[go-server] Feat: add required assertions to models (#10068)

* Add RequiredError

* Add IsZeroValue helper

* Add AssertRequired method to all models

* Add AssertRequired call for body param

* Regenerate files

* Add DisallowUnknownFields

* Regenerate samples

* Use hasRequired in model to remove unnecessary code

* Revert disallowUnknownFields

* Use isAdditionalPropertiesTrue for disallowing unknown fields

* Updated samples

* Fix indent

* Add require checks for nested slices

* Add new tests

* Regenerate samples

* Regenerate samples after merging

bin/configs/go-server-required.yaml

@@ -0,0 +1,9 @@
+generatorName: go-server
+outputDir: samples/server/petstore/go-server-required
+inputSpec: modules/openapi-generator/src/test/resources/3_0/server-required.yaml
+templateDir: modules/openapi-generator/src/main/resources/go-server
+additionalProperties:
+  hideGenerationTimestamp: "true"
+  packageName: petstoreserver
+  addResponseHeaders: true
+  router: "chi"

modules/openapi-generator/src/main/resources/go-server/controller-api.mustache

@@ -174,14 +174,36 @@ func (c *{{classname}}Controller) {{nickname}}(w http.ResponseWriter, r *http.Re
 	{{paramName}} := r.Header.Get("{{baseName}}")
 	{{/isHeaderParam}}
 	{{#isBodyParam}}
-	{{paramName}} := &{{dataType}}{}
+	{{paramName}} := {{dataType}}{}
-	if err := json.NewDecoder(r.Body).Decode(&{{paramName}}); err != nil {
+	d := json.NewDecoder(r.Body)
+	{{^isAdditionalPropertiesTrue}}
+	d.DisallowUnknownFields()
+	{{/isAdditionalPropertiesTrue}}
+	if err := d.Decode(&{{paramName}}); err != nil {
 		c.errorHandler(w, r, &ParsingError{Err: err}, nil)
 		return
 	}
+	{{#isArray}}
+		{{#items.isModel}}
+	for _, el := range {{paramName}} {
+		if err := Assert{{baseType}}Required(el); err != nil {
+			c.errorHandler(w, r, err, nil)
+			return
+		}
+	}
+		{{/items.isModel}}
+	{{/isArray}}
+	{{^isArray}}
+		{{#isModel}}
+	if err := Assert{{baseType}}Required({{paramName}}); err != nil {
+		c.errorHandler(w, r, err, nil)
+		return
+	}
+		{{/isModel}}
+	{{/isArray}}
 	{{/isBodyParam}}
 	{{/allParams}}
-	result, err := c.service.{{nickname}}(r.Context(){{#allParams}}, {{#isBodyParam}}*{{/isBodyParam}}{{paramName}}{{/allParams}})
+	result, err := c.service.{{nickname}}(r.Context(){{#allParams}}, {{paramName}}{{/allParams}})
 	// If an error occurred, encode the error with the status code
 	if err != nil {
 		c.errorHandler(w, r, err, &result)

modules/openapi-generator/src/main/resources/go-server/error.mustache

@@ -2,9 +2,16 @@
 package {{packageName}}
 
 import (
+	"errors"
+	"fmt"
 	"net/http"
 )
 
+var (
+	// ErrTypeAssertionError is thrown when type an interface does not match the asserted type
+	ErrTypeAssertionError = errors.New("unable to assert type")
+)
+
 // ParsingError indicates that an error has occurred when parsing request parameters
 type ParsingError struct {
 	Err error
@@ -18,6 +25,15 @@ func (e *ParsingError) Error() string {
 	return e.Err.Error()
 }
 
+// RequiredError indicates that an error has occurred when parsing request parameters
+type RequiredError struct {
+	Field string
+}
+
+func (e *RequiredError) Error() string {
+	return fmt.Sprintf("required field '%s' is zero value.", e.Field)
+}
+
 // ErrorHandler defines the required method for handling error. You may implement it and inject this into a controller if
 // you would like errors to be handled differently from the DefaultErrorHandler
 type ErrorHandler func(w http.ResponseWriter, r *http.Request, err error, result *ImplResponse)
@@ -28,6 +44,9 @@ func DefaultErrorHandler(w http.ResponseWriter, r *http.Request, err error, resu
 	if _, ok := err.(*ParsingError); ok {
 		// Handle parsing errors
 		EncodeJSONResponse(err.Error(), func(i int) *int { return &i }(http.StatusBadRequest),{{#addResponseHeaders}} map[string][]string{},{{/addResponseHeaders}} w)
+	} else if _, ok := err.(*RequiredError); ok {
+		// Handle missing required errors
+		EncodeJSONResponse(err.Error(), func(i int) *int { return &i }(http.StatusUnprocessableEntity),{{#addResponseHeaders}} map[string][]string{},{{/addResponseHeaders}} w)
 	} else {
 		// Handle all other errors
 		EncodeJSONResponse(err.Error(), &result.Code,{{#addResponseHeaders}} result.Headers,{{/addResponseHeaders}} w)

modules/openapi-generator/src/main/resources/go-server/helpers.mustache

@@ -1,7 +1,11 @@
 {{>partial_header}}
 package {{packageName}}
 
-//Response return a ImplResponse struct filled
+import (
+	"reflect"
+)
+
+// Response return a ImplResponse struct filled
 func Response(code int, body interface{}) ImplResponse {
 	return ImplResponse {
 		Code: code,
@@ -13,7 +17,7 @@ func Response(code int, body interface{}) ImplResponse {
 }
 {{#addResponseHeaders}}
 
-//ResponseWithHeaders return a ImplResponse struct filled, including headers
+// ResponseWithHeaders return a ImplResponse struct filled, including headers
 func ResponseWithHeaders(code int, headers map[string][]string, body interface{}) ImplResponse {
 	return ImplResponse {
 		Code: code,
@@ -22,3 +26,35 @@ func ResponseWithHeaders(code int, headers map[string][]string, body interface{}
 	}
 }
 {{/addResponseHeaders}}
+
+// IsZeroValue checks if the val is the zero-ed value.
+func IsZeroValue(val interface{}) bool {
+	return val == nil || reflect.DeepEqual(val, reflect.Zero(reflect.TypeOf(val)).Interface())
+}
+
+// AssertInterfaceRequired recursively checks each struct in a slice against the callback.
+// This method traverse nested slices in a preorder fashion.
+func AssertRecurseInterfaceRequired(obj interface{}, callback func(interface{}) error) error {
+	return AssertRecurseValueRequired(reflect.ValueOf(obj), callback)
+}
+
+// AssertNestedValueRequired checks each struct in the nested slice against the callback.
+// This method traverse nested slices in a preorder fashion.
+func AssertRecurseValueRequired(value reflect.Value, callback func(interface{}) error) error {
+	switch value.Kind() {
+	// If it is a struct we check using callback
+	case reflect.Struct:
+		if err := callback(value.Interface()); err != nil {
+			return err
+		}
+
+	// If it is a slice we continue recursion
+	case reflect.Slice:
+		for i := 0; i < value.Len(); i += 1 {
+			if err := AssertRecurseValueRequired(value.Index(i), callback); err != nil {
+				return err
+			}
+		}
+	}
+	return nil
+}

modules/openapi-generator/src/main/resources/go-server/model.mustache

@@ -34,4 +34,101 @@ type {{classname}} struct {
 	{{/deprecated}}
 	{{name}} {{#isNullable}}*{{/isNullable}}{{{dataType}}} `json:"{{baseName}}{{^required}},omitempty{{/required}}"{{#vendorExtensions.x-go-custom-tag}} {{{.}}}{{/vendorExtensions.x-go-custom-tag}}`
 {{/vars}}
-}{{/isEnum}}{{/model}}{{/models}}
+}{{/isEnum}}
+
+// Assert{{classname}}Required checks if the required fields are not zero-ed
+func Assert{{classname}}Required(obj {{classname}}) error {
+{{#hasRequired}}
+	elements := map[string]interface{}{
+{{#requiredVars}}		"{{baseName}}": obj.{{name}},
+{{/requiredVars}}	}
+	for name, el := range elements {
+		if isZero := IsZeroValue(el); isZero {
+			return &RequiredError{Field: name}
+		}
+	}
+
+{{/hasRequired}}
+{{#parent}}
+	{{^isMap}}
+		{{^isArray}}
+	if err := Assert{{{parent}}}Required(obj.{{{parent}}}); err != nil {
+		return err
+	}
+
+		{{/isArray}}
+	{{/isMap}}
+{{/parent}}
+{{#Vars}}
+	{{#isNullable}}
+		{{#isModel}}
+	if obj.{{name}} != nil {
+		{{/isModel}}
+		{{#isArray}}
+			{{#items.isModel}}
+	if obj.{{name}} != nil {
+			{{/items.isModel}}
+			{{^items.isModel}}
+				{{#mostInnerItems.isModel}}
+					{{^mostInnerItems.isPrimitiveType}}
+	if obj.{{name}} != nil {
+					{{/mostInnerItems.isPrimitiveType}}
+				{{/mostInnerItems.isModel}}
+			{{/items.isModel}}
+		{{/isArray}}
+	{{/isNullable}}
+	{{#isModel}}
+{{#isNullable}}	{{/isNullable}}	if err := Assert{{baseType}}Required({{#isNullable}}*{{/isNullable}}obj.{{name}}); err != nil {
+{{#isNullable}}	{{/isNullable}}		return err
+{{#isNullable}}	{{/isNullable}}	}
+	{{/isModel}}
+	{{#isArray}}
+		{{#items.isModel}}
+{{#isNullable}}	{{/isNullable}}	for _, el := range {{#isNullable}}*{{/isNullable}}obj.{{name}} {
+{{#isNullable}}	{{/isNullable}}		if err := Assert{{items.baseType}}Required(el); err != nil {
+{{#isNullable}}	{{/isNullable}}			return err
+{{#isNullable}}	{{/isNullable}}		}
+{{#isNullable}}	{{/isNullable}}	}
+		{{/items.isModel}}
+		{{^items.isModel}}
+			{{#mostInnerItems.isModel}}
+				{{^mostInnerItems.isPrimitiveType}}
+{{#isNullable}}	{{/isNullable}}	if err := AssertRecurse{{mostInnerItems.dataType}}Required({{#isNullable}}*{{/isNullable}}obj.{{name}}); err != nil {
+{{#isNullable}}	{{/isNullable}}		return err
+{{#isNullable}}	{{/isNullable}}	}
+				{{/mostInnerItems.isPrimitiveType}}
+			{{/mostInnerItems.isModel}}
+		{{/items.isModel}}
+	{{/isArray}}
+	{{#isNullable}}
+		{{#isModel}}
+	}
+		{{/isModel}}
+		{{#isArray}}
+			{{#items.isModel}}
+	}
+			{{/items.isModel}}
+			{{^items.isModel}}
+				{{#mostInnerItems.isModel}}
+					{{^mostInnerItems.isPrimitiveType}}
+	}
+					{{/mostInnerItems.isPrimitiveType}}
+				{{/mostInnerItems.isModel}}
+			{{/items.isModel}}
+		{{/isArray}}
+	{{/isNullable}}
+{{/Vars}}
+	return nil
+}
+
+// AssertRecurse{{classname}}Required recursively checks if required fields are not zero-ed in a nested slice.
+// Accepts only nested slice of {{classname}} (e.g. [][]{{classname}}), otherwise ErrTypeAssertionError is thrown.
+func AssertRecurse{{classname}}Required(objSlice interface{}) error {
+	return AssertRecurseInterfaceRequired(objSlice, func(obj interface{}) error {
+		a{{classname}}, ok := obj.({{classname}})
+		if !ok {
+			return ErrTypeAssertionError
+		}
+		return Assert{{classname}}Required(a{{classname}})
+	})
+}{{/model}}{{/models}}

modules/openapi-generator/src/test/resources/3_0/server-required.yaml

@@ -0,0 +1,800 @@
+openapi: 3.0.0
+servers:
+  - url: "http://petstore.swagger.io/v2"
+info:
+  description: >-
+    This is a sample server Petstore server. For this sample, you can use the api key
+    `special-key` to test the authorization filters.
+  version: 1.0.0
+  title: OpenAPI Petstore
+  license:
+    name: Apache-2.0
+    url: "https://www.apache.org/licenses/LICENSE-2.0.html"
+tags:
+  - name: pet
+    description: Everything about your Pets
+  - name: store
+    description: Access to Petstore orders
+  - name: user
+    description: Operations about user
+paths:
+  /pet:
+    post:
+      tags:
+        - pet
+      summary: Add a new pet to the store
+      description: ""
+      operationId: addPet
+      responses:
+        "200":
+          description: successful operation
+          content:
+            application/xml:
+              schema:
+                $ref: "#/components/schemas/Pet"
+            application/json:
+              schema:
+                $ref: "#/components/schemas/Pet"
+        "405":
+          description: Invalid input
+      security:
+        - petstore_auth:
+            - "write:pets"
+            - "read:pets"
+      requestBody:
+        $ref: "#/components/requestBodies/Pet"
+    put:
+      tags:
+        - pet
+      summary: Update an existing pet
+      description: ""
+      operationId: updatePet
+      responses:
+        "200":
+          description: successful operation
+          content:
+            application/xml:
+              schema:
+                $ref: "#/components/schemas/Pet"
+            application/json:
+              schema:
+                $ref: "#/components/schemas/Pet"
+        "400":
+          description: Invalid ID supplied
+        "404":
+          description: Pet not found
+        "405":
+          description: Validation exception
+      security:
+        - petstore_auth:
+            - "write:pets"
+            - "read:pets"
+      requestBody:
+        $ref: "#/components/requestBodies/Pet"
+  /pet/findByStatus:
+    get:
+      tags:
+        - pet
+      summary: Finds Pets by status
+      description: Multiple status values can be provided with comma separated strings
+      operationId: findPetsByStatus
+      parameters:
+        - name: status
+          in: query
+          description: Status values that need to be considered for filter
+          required: true
+          style: form
+          explode: false
+          schema:
+            type: array
+            items:
+              type: string
+              enum:
+                - available
+                - pending
+                - sold
+              default: available
+      responses:
+        "200":
+          description: successful operation
+          content:
+            application/xml:
+              schema:
+                type: array
+                items:
+                  $ref: "#/components/schemas/Pet"
+            application/json:
+              schema:
+                type: array
+                items:
+                  $ref: "#/components/schemas/Pet"
+        "400":
+          description: Invalid status value
+      security:
+        - petstore_auth:
+            - "read:pets"
+  /pet/findByTags:
+    get:
+      tags:
+        - pet
+      summary: Finds Pets by tags
+      description: >-
+        Multiple tags can be provided with comma separated strings. Use tag1,
+        tag2, tag3 for testing.
+      operationId: findPetsByTags
+      parameters:
+        - name: tags
+          in: query
+          description: Tags to filter by
+          required: true
+          style: form
+          explode: false
+          schema:
+            type: array
+            items:
+              type: string
+      responses:
+        "200":
+          description: successful operation
+          content:
+            application/xml:
+              schema:
+                type: array
+                items:
+                  $ref: "#/components/schemas/Pet"
+            application/json:
+              schema:
+                type: array
+                items:
+                  $ref: "#/components/schemas/Pet"
+        "400":
+          description: Invalid tag value
+      security:
+        - petstore_auth:
+            - "read:pets"
+      deprecated: true
+  "/pet/{petId}":
+    get:
+      tags:
+        - pet
+      summary: Find pet by ID
+      description: Returns a single pet
+      operationId: getPetById
+      parameters:
+        - name: petId
+          in: path
+          description: ID of pet to return
+          required: true
+          schema:
+            type: integer
+            format: int64
+      responses:
+        "200":
+          description: successful operation
+          content:
+            application/xml:
+              schema:
+                $ref: "#/components/schemas/Pet"
+            application/json:
+              schema:
+                $ref: "#/components/schemas/Pet"
+        "400":
+          description: Invalid ID supplied
+        "404":
+          description: Pet not found
+      security:
+        - api_key: []
+    post:
+      tags:
+        - pet
+      summary: Updates a pet in the store with form data
+      description: ""
+      operationId: updatePetWithForm
+      parameters:
+        - name: petId
+          in: path
+          description: ID of pet that needs to be updated
+          required: true
+          schema:
+            type: integer
+            format: int64
+      responses:
+        "405":
+          description: Invalid input
+      security:
+        - petstore_auth:
+            - "write:pets"
+            - "read:pets"
+      requestBody:
+        content:
+          application/x-www-form-urlencoded:
+            schema:
+              type: object
+              properties:
+                name:
+                  description: Updated name of the pet
+                  type: string
+                status:
+                  description: Updated status of the pet
+                  type: string
+    delete:
+      tags:
+        - pet
+      summary: Deletes a pet
+      description: ""
+      operationId: deletePet
+      parameters:
+        - name: api_key
+          in: header
+          required: false
+          schema:
+            type: string
+        - name: petId
+          in: path
+          description: Pet id to delete
+          required: true
+          schema:
+            type: integer
+            format: int64
+      responses:
+        "400":
+          description: Invalid pet value
+      security:
+        - petstore_auth:
+            - "write:pets"
+            - "read:pets"
+  "/pet/{petId}/uploadImage":
+    post:
+      tags:
+        - pet
+      summary: uploads an image
+      description: ""
+      operationId: uploadFile
+      parameters:
+        - name: petId
+          in: path
+          description: ID of pet to update
+          required: true
+          schema:
+            type: integer
+            format: int64
+      responses:
+        "200":
+          description: successful operation
+          content:
+            application/json:
+              schema:
+                $ref: "#/components/schemas/ApiResponse"
+      security:
+        - petstore_auth:
+            - "write:pets"
+            - "read:pets"
+      requestBody:
+        content:
+          multipart/form-data:
+            schema:
+              type: object
+              properties:
+                additionalMetadata:
+                  description: Additional data to pass to server
+                  type: string
+                file:
+                  description: file to upload
+                  type: string
+                  format: binary
+  /store/inventory:
+    get:
+      tags:
+        - store
+      summary: Returns pet inventories by status
+      description: Returns a map of status codes to quantities
+      operationId: getInventory
+      responses:
+        "200":
+          description: successful operation
+          content:
+            application/json:
+              schema:
+                type: object
+                additionalProperties:
+                  type: integer
+                  format: int32
+      security:
+        - api_key: []
+  /store/order:
+    post:
+      tags:
+        - store
+      summary: Place an order for a pet
+      description: ""
+      operationId: placeOrder
+      responses:
+        "200":
+          description: successful operation
+          content:
+            application/xml:
+              schema:
+                $ref: "#/components/schemas/Order"
+            application/json:
+              schema:
+                $ref: "#/components/schemas/Order"
+        "400":
+          description: Invalid Order
+      requestBody:
+        content:
+          application/json:
+            schema:
+              $ref: "#/components/schemas/Order"
+        description: order placed for purchasing the pet
+        required: true
+  "/store/order/{orderId}":
+    get:
+      tags:
+        - store
+      summary: Find purchase order by ID
+      description: >-
+        For valid response try integer IDs with value <= 5 or > 10. Other values
+        will generated exceptions
+      operationId: getOrderById
+      parameters:
+        - name: orderId
+          in: path
+          description: ID of pet that needs to be fetched
+          required: true
+          schema:
+            type: integer
+            format: int64
+            minimum: 1
+            maximum: 5
+      responses:
+        "200":
+          description: successful operation
+          content:
+            application/xml:
+              schema:
+                $ref: "#/components/schemas/Order"
+            application/json:
+              schema:
+                $ref: "#/components/schemas/Order"
+        "400":
+          description: Invalid ID supplied
+        "404":
+          description: Order not found
+    delete:
+      tags:
+        - store
+      summary: Delete purchase order by ID
+      description: >-
+        For valid response try integer IDs with value < 1000. Anything above
+        1000 or nonintegers will generate API errors
+      operationId: deleteOrder
+      parameters:
+        - name: orderId
+          in: path
+          description: ID of the order that needs to be deleted
+          required: true
+          schema:
+            type: string
+      responses:
+        "400":
+          description: Invalid ID supplied
+        "404":
+          description: Order not found
+  /user:
+    post:
+      tags:
+        - user
+      summary: Create user
+      description: This can only be done by the logged in user.
+      operationId: createUser
+      responses:
+        default:
+          description: successful operation
+      security:
+        - api_key: []
+      requestBody:
+        content:
+          application/json:
+            schema:
+              $ref: "#/components/schemas/User"
+        description: Created user object
+        required: true
+  /user/createWithArray:
+    post:
+      tags:
+        - user
+      summary: Creates list of users with given input array
+      description: ""
+      operationId: createUsersWithArrayInput
+      responses:
+        default:
+          description: successful operation
+      security:
+        - api_key: []
+      requestBody:
+        $ref: "#/components/requestBodies/UserArray"
+  /user/createWithList:
+    post:
+      tags:
+        - user
+      summary: Creates list of users with given input array
+      description: ""
+      operationId: createUsersWithListInput
+      responses:
+        default:
+          description: successful operation
+      security:
+        - api_key: []
+      requestBody:
+        $ref: "#/components/requestBodies/UserArray"
+  /user/login:
+    get:
+      tags:
+        - user
+      summary: Logs user into the system
+      description: ""
+      operationId: loginUser
+      parameters:
+        - name: username
+          in: query
+          description: The user name for login
+          required: true
+          schema:
+            type: string
+            pattern: '^[a-zA-Z0-9]+[a-zA-Z0-9\.\-_]*[a-zA-Z0-9]+$'
+        - name: password
+          in: query
+          description: The password for login in clear text
+          required: true
+          schema:
+            type: string
+      responses:
+        "200":
+          description: successful operation
+          headers:
+            Set-Cookie:
+              description: >-
+                Cookie authentication key for use with the `api_key`
+                apiKey authentication.
+              schema:
+                type: string
+                example: AUTH_KEY=abcde12345; Path=/; HttpOnly
+            X-Rate-Limit:
+              description: calls per hour allowed by the user
+              schema:
+                type: integer
+                format: int32
+            X-Expires-After:
+              description: date in UTC when toekn expires
+              schema:
+                type: string
+                format: date-time
+          content:
+            application/xml:
+              schema:
+                type: string
+            application/json:
+              schema:
+                type: string
+        "400":
+          description: Invalid username/password supplied
+  /user/logout:
+    get:
+      tags:
+        - user
+      summary: Logs out current logged in user session
+      description: ""
+      operationId: logoutUser
+      responses:
+        default:
+          description: successful operation
+      security:
+        - api_key: []
+  "/user/{username}":
+    get:
+      tags:
+        - user
+      summary: Get user by user name
+      description: ""
+      operationId: getUserByName
+      parameters:
+        - name: username
+          in: path
+          description: The name that needs to be fetched. Use user1 for testing.
+          required: true
+          schema:
+            type: string
+      responses:
+        "200":
+          description: successful operation
+          content:
+            application/xml:
+              schema:
+                $ref: "#/components/schemas/User"
+            application/json:
+              schema:
+                $ref: "#/components/schemas/User"
+        "400":
+          description: Invalid username supplied
+        "404":
+          description: User not found
+    put:
+      tags:
+        - user
+      summary: Updated user
+      description: This can only be done by the logged in user.
+      operationId: updateUser
+      parameters:
+        - name: username
+          in: path
+          description: name that need to be deleted
+          required: true
+          schema:
+            type: string
+      responses:
+        "400":
+          description: Invalid user supplied
+        "404":
+          description: User not found
+      security:
+        - api_key: []
+      requestBody:
+        content:
+          application/json:
+            schema:
+              $ref: "#/components/schemas/User"
+        description: Updated user object
+        required: true
+    delete:
+      tags:
+        - user
+      summary: Delete user
+      description: This can only be done by the logged in user.
+      operationId: deleteUser
+      parameters:
+        - name: username
+          in: path
+          description: The name that needs to be deleted
+          required: true
+          schema:
+            type: string
+      responses:
+        "400":
+          description: Invalid username supplied
+        "404":
+          description: User not found
+      security:
+        - api_key: []
+externalDocs:
+  description: Find out more about Swagger
+  url: "http://swagger.io"
+components:
+  requestBodies:
+    UserArray:
+      content:
+        application/json:
+          schema:
+            type: array
+            items:
+              $ref: "#/components/schemas/User"
+      description: List of user object
+      required: true
+    Pet:
+      content:
+        application/json:
+          schema:
+            $ref: "#/components/schemas/Pet"
+        application/xml:
+          schema:
+            $ref: "#/components/schemas/Pet"
+      description: Pet object that needs to be added to the store
+      required: true
+  securitySchemes:
+    petstore_auth:
+      type: oauth2
+      flows:
+        implicit:
+          authorizationUrl: "http://petstore.swagger.io/api/oauth/dialog"
+          scopes:
+            "write:pets": modify pets in your account
+            "read:pets": read your pets
+    api_key:
+      type: apiKey
+      name: api_key
+      in: header
+  schemas:
+    OrderInfo:
+      title: Pet Order Info
+      description: An order info for a pets from the pet store
+      type: object
+      properties:
+        petId:
+          type: integer
+          format: int64
+        quantity:
+          type: integer
+          format: int32
+        shipDate:
+          type: string
+          format: date-time
+      xml:
+        name: OrderInfo
+    SpecialInfo:
+      title: Pet Order Info
+      description: An order info for a pets from the pet store
+      discriminator:
+        propertyName: type
+      type: object
+      properties:
+        promotion:
+          type: boolean
+        type:
+          type: string
+      xml:
+        name: OrderInfo
+    Order:
+      title: Pet Order
+      description: An order for a pets from the pet store
+      allOf:
+        - $ref: '#/components/schemas/OrderInfo'
+        - $ref: '#/components/schemas/SpecialInfo'
+      type: object
+      properties:
+        id:
+          type: integer
+          format: int64
+        status:
+          type: string
+          description: Order Status
+          enum:
+            - placed
+            - approved
+            - delivered
+        complete:
+          type: boolean
+          default: false
+        comment:
+          type: string
+          nullable: true
+      xml:
+        name: Order
+      required:
+        - comment
+    Category:
+      title: Pet category
+      description: A category for a pet
+      type: object
+      nullable: true
+      properties:
+        id:
+          type: integer
+          format: int64
+        name:
+          type: string
+          pattern: '^[a-zA-Z0-9]+[a-zA-Z0-9\.\-_]*[a-zA-Z0-9]+$'
+      xml:
+        name: Category
+    User:
+      title: a User
+      description: A User who is purchasing from the pet store
+      type: object
+      properties:
+        id:
+          type: integer
+          format: int64
+        username:
+          type: string
+        firstName:
+          type: string
+        lastName:
+          type: string
+        email:
+          type: string
+        password:
+          type: string
+        phone:
+          type: string
+          nullable: true
+        userStatus:
+          type: integer
+          format: int32
+          description: User Status
+        deepSliceModel:
+          nullable: true
+          type: array
+          description: An array 1-deep.
+          items:
+            type: array
+            description: An array 2-deep.
+            items:
+              type: array
+              description: An array 3-deep.
+              items:
+                $ref: "#/components/schemas/Tag"
+        deepSliceMap:
+          type: array
+          description: An array 1-deep.
+          items:
+            type: array
+            description: An array 2-deep.
+            items:
+              title: an Object
+              type: object
+              description: An array 3-deep.
+              properties:
+                tag:
+                  $ref: "#/components/schemas/Tag"
+                Pet:
+                  type: array
+                  description: An array of pet.
+                  items:
+                    $ref: "#/components/schemas/Pet"
+      xml:
+        name: User
+      required:
+        - deepSliceModel
+    Tag:
+      title: Pet Tag
+      description: A tag for a pet
+      type: object
+      properties:
+        id:
+          type: integer
+          format: int64
+        name:
+          type: string
+      xml:
+        name: Tag
+    Pet:
+      title: a Pet
+      description: A pet for sale in the pet store
+      type: object
+      required:
+        - name
+        - photoUrls
+      properties:
+        id:
+          type: integer
+          format: int64
+        category:
+          $ref: "#/components/schemas/Category"
+        name:
+          type: string
+          example: doggie
+        photoUrls:
+          nullable: true
+          type: array
+          xml:
+            name: photoUrl
+            wrapped: true
+          items:
+            type: string
+        tags:
+          nullable: true
+          type: array
+          xml:
+            name: tag
+            wrapped: true
+          items:
+            $ref: "#/components/schemas/Tag"
+        status:
+          type: string
+          description: pet status in the store
+          enum:
+            - available
+            - pending
+            - sold
+      xml:
+        name: Pet
+    ApiResponse:
+      title: An uploaded response
+      description: Describes the result of uploading an image resource
+      type: object
+      properties:
+        code:
+          type: integer
+          format: int32
+        type:
+          type: string
+        message:
+          type: string

samples/server/petstore/go-api-server/go/api_pet.go

@@ -103,12 +103,18 @@ func (c *PetApiController) Routes() Routes {
 
 // AddPet - Add a new pet to the store
 func (c *PetApiController) AddPet(w http.ResponseWriter, r *http.Request) {
-	pet := &Pet{}
+	pet := Pet{}
-	if err := json.NewDecoder(r.Body).Decode(&pet); err != nil {
+	d := json.NewDecoder(r.Body)
+	d.DisallowUnknownFields()
+	if err := d.Decode(&pet); err != nil {
 		c.errorHandler(w, r, &ParsingError{Err: err}, nil)
 		return
 	}
-	result, err := c.service.AddPet(r.Context(), *pet)
+	if err := AssertPetRequired(pet); err != nil {
+		c.errorHandler(w, r, err, nil)
+		return
+	}
+	result, err := c.service.AddPet(r.Context(), pet)
 	// If an error occurred, encode the error with the status code
 	if err != nil {
 		c.errorHandler(w, r, err, &result)
@@ -193,12 +199,18 @@ func (c *PetApiController) GetPetById(w http.ResponseWriter, r *http.Request) {
 
 // UpdatePet - Update an existing pet
 func (c *PetApiController) UpdatePet(w http.ResponseWriter, r *http.Request) {
-	pet := &Pet{}
+	pet := Pet{}
-	if err := json.NewDecoder(r.Body).Decode(&pet); err != nil {
+	d := json.NewDecoder(r.Body)
+	d.DisallowUnknownFields()
+	if err := d.Decode(&pet); err != nil {
 		c.errorHandler(w, r, &ParsingError{Err: err}, nil)
 		return
 	}
-	result, err := c.service.UpdatePet(r.Context(), *pet)
+	if err := AssertPetRequired(pet); err != nil {
+		c.errorHandler(w, r, err, nil)
+		return
+	}
+	result, err := c.service.UpdatePet(r.Context(), pet)
 	// If an error occurred, encode the error with the status code
 	if err != nil {
 		c.errorHandler(w, r, err, &result)

samples/server/petstore/go-api-server/go/api_store.go

@@ -128,12 +128,18 @@ func (c *StoreApiController) GetOrderById(w http.ResponseWriter, r *http.Request
 
 // PlaceOrder - Place an order for a pet
 func (c *StoreApiController) PlaceOrder(w http.ResponseWriter, r *http.Request) {
-	order := &Order{}
+	order := Order{}
-	if err := json.NewDecoder(r.Body).Decode(&order); err != nil {
+	d := json.NewDecoder(r.Body)
+	d.DisallowUnknownFields()
+	if err := d.Decode(&order); err != nil {
 		c.errorHandler(w, r, &ParsingError{Err: err}, nil)
 		return
 	}
-	result, err := c.service.PlaceOrder(r.Context(), *order)
+	if err := AssertOrderRequired(order); err != nil {
+		c.errorHandler(w, r, err, nil)
+		return
+	}
+	result, err := c.service.PlaceOrder(r.Context(), order)
 	// If an error occurred, encode the error with the status code
 	if err != nil {
 		c.errorHandler(w, r, err, &result)

samples/server/petstore/go-api-server/go/api_user.go

@@ -103,12 +103,18 @@ func (c *UserApiController) Routes() Routes {
 
 // CreateUser - Create user
 func (c *UserApiController) CreateUser(w http.ResponseWriter, r *http.Request) {
-	user := &User{}
+	user := User{}
-	if err := json.NewDecoder(r.Body).Decode(&user); err != nil {
+	d := json.NewDecoder(r.Body)
+	d.DisallowUnknownFields()
+	if err := d.Decode(&user); err != nil {
 		c.errorHandler(w, r, &ParsingError{Err: err}, nil)
 		return
 	}
-	result, err := c.service.CreateUser(r.Context(), *user)
+	if err := AssertUserRequired(user); err != nil {
+		c.errorHandler(w, r, err, nil)
+		return
+	}
+	result, err := c.service.CreateUser(r.Context(), user)
 	// If an error occurred, encode the error with the status code
 	if err != nil {
 		c.errorHandler(w, r, err, &result)
@@ -121,12 +127,20 @@ func (c *UserApiController) CreateUser(w http.ResponseWriter, r *http.Request) {
 
 // CreateUsersWithArrayInput - Creates list of users with given input array
 func (c *UserApiController) CreateUsersWithArrayInput(w http.ResponseWriter, r *http.Request) {
-	user := &[]User{}
+	user := []User{}
-	if err := json.NewDecoder(r.Body).Decode(&user); err != nil {
+	d := json.NewDecoder(r.Body)
+	d.DisallowUnknownFields()
+	if err := d.Decode(&user); err != nil {
 		c.errorHandler(w, r, &ParsingError{Err: err}, nil)
 		return
 	}
-	result, err := c.service.CreateUsersWithArrayInput(r.Context(), *user)
+	for _, el := range user {
+		if err := AssertUserRequired(el); err != nil {
+			c.errorHandler(w, r, err, nil)
+			return
+		}
+	}
+	result, err := c.service.CreateUsersWithArrayInput(r.Context(), user)
 	// If an error occurred, encode the error with the status code
 	if err != nil {
 		c.errorHandler(w, r, err, &result)
@@ -139,12 +153,20 @@ func (c *UserApiController) CreateUsersWithArrayInput(w http.ResponseWriter, r *
 
 // CreateUsersWithListInput - Creates list of users with given input array
 func (c *UserApiController) CreateUsersWithListInput(w http.ResponseWriter, r *http.Request) {
-	user := &[]User{}
+	user := []User{}
-	if err := json.NewDecoder(r.Body).Decode(&user); err != nil {
+	d := json.NewDecoder(r.Body)
+	d.DisallowUnknownFields()
+	if err := d.Decode(&user); err != nil {
 		c.errorHandler(w, r, &ParsingError{Err: err}, nil)
 		return
 	}
-	result, err := c.service.CreateUsersWithListInput(r.Context(), *user)
+	for _, el := range user {
+		if err := AssertUserRequired(el); err != nil {
+			c.errorHandler(w, r, err, nil)
+			return
+		}
+	}
+	result, err := c.service.CreateUsersWithListInput(r.Context(), user)
 	// If an error occurred, encode the error with the status code
 	if err != nil {
 		c.errorHandler(w, r, err, &result)
@@ -221,12 +243,18 @@ func (c *UserApiController) UpdateUser(w http.ResponseWriter, r *http.Request) {
 	params := mux.Vars(r)
 	username := params["username"]
 	
-	user := &User{}
+	user := User{}
-	if err := json.NewDecoder(r.Body).Decode(&user); err != nil {
+	d := json.NewDecoder(r.Body)
+	d.DisallowUnknownFields()
+	if err := d.Decode(&user); err != nil {
 		c.errorHandler(w, r, &ParsingError{Err: err}, nil)
 		return
 	}
-	result, err := c.service.UpdateUser(r.Context(), username, *user)
+	if err := AssertUserRequired(user); err != nil {
+		c.errorHandler(w, r, err, nil)
+		return
+	}
+	result, err := c.service.UpdateUser(r.Context(), username, user)
 	// If an error occurred, encode the error with the status code
 	if err != nil {
 		c.errorHandler(w, r, err, &result)

samples/server/petstore/go-api-server/go/error.go

@@ -10,9 +10,16 @@
 package petstoreserver
 
 import (
+	"errors"
+	"fmt"
 	"net/http"
 )
 
+var (
+	// ErrTypeAssertionError is thrown when type an interface does not match the asserted type
+	ErrTypeAssertionError = errors.New("unable to assert type")
+)
+
 // ParsingError indicates that an error has occurred when parsing request parameters
 type ParsingError struct {
 	Err error
@@ -26,6 +33,15 @@ func (e *ParsingError) Error() string {
 	return e.Err.Error()
 }
 
+// RequiredError indicates that an error has occurred when parsing request parameters
+type RequiredError struct {
+	Field string
+}
+
+func (e *RequiredError) Error() string {
+	return fmt.Sprintf("required field '%s' is zero value.", e.Field)
+}
+
 // ErrorHandler defines the required method for handling error. You may implement it and inject this into a controller if
 // you would like errors to be handled differently from the DefaultErrorHandler
 type ErrorHandler func(w http.ResponseWriter, r *http.Request, err error, result *ImplResponse)
@@ -36,6 +52,9 @@ func DefaultErrorHandler(w http.ResponseWriter, r *http.Request, err error, resu
 	if _, ok := err.(*ParsingError); ok {
 		// Handle parsing errors
 		EncodeJSONResponse(err.Error(), func(i int) *int { return &i }(http.StatusBadRequest), map[string][]string{}, w)
+	} else if _, ok := err.(*RequiredError); ok {
+		// Handle missing required errors
+		EncodeJSONResponse(err.Error(), func(i int) *int { return &i }(http.StatusUnprocessableEntity), map[string][]string{}, w)
 	} else {
 		// Handle all other errors
 		EncodeJSONResponse(err.Error(), &result.Code, result.Headers, w)

samples/server/petstore/go-api-server/go/helpers.go

@@ -9,7 +9,11 @@
 
 package petstoreserver
 
-//Response return a ImplResponse struct filled
+import (
+	"reflect"
+)
+
+// Response return a ImplResponse struct filled
 func Response(code int, body interface{}) ImplResponse {
 	return ImplResponse {
 		Code: code,
@@ -18,7 +22,7 @@ func Response(code int, body interface{}) ImplResponse {
 	}
 }
 
-//ResponseWithHeaders return a ImplResponse struct filled, including headers
+// ResponseWithHeaders return a ImplResponse struct filled, including headers
 func ResponseWithHeaders(code int, headers map[string][]string, body interface{}) ImplResponse {
 	return ImplResponse {
 		Code: code,
@@ -26,3 +30,35 @@ func ResponseWithHeaders(code int, headers map[string][]string, body interface{}
 		Body: body,
 	}
 }
+
+// IsZeroValue checks if the val is the zero-ed value.
+func IsZeroValue(val interface{}) bool {
+	return val == nil || reflect.DeepEqual(val, reflect.Zero(reflect.TypeOf(val)).Interface())
+}
+
+// AssertInterfaceRequired recursively checks each struct in a slice against the callback.
+// This method traverse nested slices in a preorder fashion.
+func AssertRecurseInterfaceRequired(obj interface{}, callback func(interface{}) error) error {
+	return AssertRecurseValueRequired(reflect.ValueOf(obj), callback)
+}
+
+// AssertNestedValueRequired checks each struct in the nested slice against the callback.
+// This method traverse nested slices in a preorder fashion.
+func AssertRecurseValueRequired(value reflect.Value, callback func(interface{}) error) error {
+	switch value.Kind() {
+	// If it is a struct we check using callback
+	case reflect.Struct:
+		if err := callback(value.Interface()); err != nil {
+			return err
+		}
+
+	// If it is a slice we continue recursion
+	case reflect.Slice:
+		for i := 0; i < value.Len(); i += 1 {
+			if err := AssertRecurseValueRequired(value.Index(i), callback); err != nil {
+				return err
+			}
+		}
+	}
+	return nil
+}

samples/server/petstore/go-api-server/go/model_api_response.go

@@ -18,3 +18,20 @@ type ApiResponse struct {
 
 	Message string `json:"message,omitempty"`
 }
+
+// AssertApiResponseRequired checks if the required fields are not zero-ed
+func AssertApiResponseRequired(obj ApiResponse) error {
+	return nil
+}
+
+// AssertRecurseApiResponseRequired recursively checks if required fields are not zero-ed in a nested slice.
+// Accepts only nested slice of ApiResponse (e.g. [][]ApiResponse), otherwise ErrTypeAssertionError is thrown.
+func AssertRecurseApiResponseRequired(objSlice interface{}) error {
+	return AssertRecurseInterfaceRequired(objSlice, func(obj interface{}) error {
+		aApiResponse, ok := obj.(ApiResponse)
+		if !ok {
+			return ErrTypeAssertionError
+		}
+		return AssertApiResponseRequired(aApiResponse)
+	})
+}

samples/server/petstore/go-api-server/go/model_category.go

@@ -16,3 +16,20 @@ type Category struct {
 
 	Name string `json:"name,omitempty"`
 }
+
+// AssertCategoryRequired checks if the required fields are not zero-ed
+func AssertCategoryRequired(obj Category) error {
+	return nil
+}
+
+// AssertRecurseCategoryRequired recursively checks if required fields are not zero-ed in a nested slice.
+// Accepts only nested slice of Category (e.g. [][]Category), otherwise ErrTypeAssertionError is thrown.
+func AssertRecurseCategoryRequired(objSlice interface{}) error {
+	return AssertRecurseInterfaceRequired(objSlice, func(obj interface{}) error {
+		aCategory, ok := obj.(Category)
+		if !ok {
+			return ErrTypeAssertionError
+		}
+		return AssertCategoryRequired(aCategory)
+	})
+}

samples/server/petstore/go-api-server/go/model_order.go

@@ -29,3 +29,20 @@ type Order struct {
 
 	Complete bool `json:"complete,omitempty"`
 }
+
+// AssertOrderRequired checks if the required fields are not zero-ed
+func AssertOrderRequired(obj Order) error {
+	return nil
+}
+
+// AssertRecurseOrderRequired recursively checks if required fields are not zero-ed in a nested slice.
+// Accepts only nested slice of Order (e.g. [][]Order), otherwise ErrTypeAssertionError is thrown.
+func AssertRecurseOrderRequired(objSlice interface{}) error {
+	return AssertRecurseInterfaceRequired(objSlice, func(obj interface{}) error {
+		aOrder, ok := obj.(Order)
+		if !ok {
+			return ErrTypeAssertionError
+		}
+		return AssertOrderRequired(aOrder)
+	})
+}

samples/server/petstore/go-api-server/go/model_pet.go

@@ -26,3 +26,38 @@ type Pet struct {
 	// Deprecated
 	Status string `json:"status,omitempty"`
 }
+
+// AssertPetRequired checks if the required fields are not zero-ed
+func AssertPetRequired(obj Pet) error {
+	elements := map[string]interface{}{
+		"name": obj.Name,
+		"photoUrls": obj.PhotoUrls,
+	}
+	for name, el := range elements {
+		if isZero := IsZeroValue(el); isZero {
+			return &RequiredError{Field: name}
+		}
+	}
+
+	if err := AssertCategoryRequired(obj.Category); err != nil {
+		return err
+	}
+	for _, el := range obj.Tags {
+		if err := AssertTagRequired(el); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+// AssertRecursePetRequired recursively checks if required fields are not zero-ed in a nested slice.
+// Accepts only nested slice of Pet (e.g. [][]Pet), otherwise ErrTypeAssertionError is thrown.
+func AssertRecursePetRequired(objSlice interface{}) error {
+	return AssertRecurseInterfaceRequired(objSlice, func(obj interface{}) error {
+		aPet, ok := obj.(Pet)
+		if !ok {
+			return ErrTypeAssertionError
+		}
+		return AssertPetRequired(aPet)
+	})
+}

samples/server/petstore/go-api-server/go/model_tag.go

@@ -16,3 +16,20 @@ type Tag struct {
 
 	Name string `json:"name,omitempty"`
 }
+
+// AssertTagRequired checks if the required fields are not zero-ed
+func AssertTagRequired(obj Tag) error {
+	return nil
+}
+
+// AssertRecurseTagRequired recursively checks if required fields are not zero-ed in a nested slice.
+// Accepts only nested slice of Tag (e.g. [][]Tag), otherwise ErrTypeAssertionError is thrown.
+func AssertRecurseTagRequired(objSlice interface{}) error {
+	return AssertRecurseInterfaceRequired(objSlice, func(obj interface{}) error {
+		aTag, ok := obj.(Tag)
+		if !ok {
+			return ErrTypeAssertionError
+		}
+		return AssertTagRequired(aTag)
+	})
+}

samples/server/petstore/go-api-server/go/model_user.go

@@ -29,3 +29,20 @@ type User struct {
 	// User Status
 	UserStatus int32 `json:"userStatus,omitempty"`
 }
+
+// AssertUserRequired checks if the required fields are not zero-ed
+func AssertUserRequired(obj User) error {
+	return nil
+}
+
+// AssertRecurseUserRequired recursively checks if required fields are not zero-ed in a nested slice.
+// Accepts only nested slice of User (e.g. [][]User), otherwise ErrTypeAssertionError is thrown.
+func AssertRecurseUserRequired(objSlice interface{}) error {
+	return AssertRecurseInterfaceRequired(objSlice, func(obj interface{}) error {
+		aUser, ok := obj.(User)
+		if !ok {
+			return ErrTypeAssertionError
+		}
+		return AssertUserRequired(aUser)
+	})
+}

samples/server/petstore/go-chi-server/go/api_pet.go

@@ -103,12 +103,18 @@ func (c *PetApiController) Routes() Routes {
 
 // AddPet - Add a new pet to the store
 func (c *PetApiController) AddPet(w http.ResponseWriter, r *http.Request) {
-	pet := &Pet{}
+	pet := Pet{}
-	if err := json.NewDecoder(r.Body).Decode(&pet); err != nil {
+	d := json.NewDecoder(r.Body)
+	d.DisallowUnknownFields()
+	if err := d.Decode(&pet); err != nil {
 		c.errorHandler(w, r, &ParsingError{Err: err}, nil)
 		return
 	}
-	result, err := c.service.AddPet(r.Context(), *pet)
+	if err := AssertPetRequired(pet); err != nil {
+		c.errorHandler(w, r, err, nil)
+		return
+	}
+	result, err := c.service.AddPet(r.Context(), pet)
 	// If an error occurred, encode the error with the status code
 	if err != nil {
 		c.errorHandler(w, r, err, &result)
@@ -191,12 +197,18 @@ func (c *PetApiController) GetPetById(w http.ResponseWriter, r *http.Request) {
 
 // UpdatePet - Update an existing pet
 func (c *PetApiController) UpdatePet(w http.ResponseWriter, r *http.Request) {
-	pet := &Pet{}
+	pet := Pet{}
-	if err := json.NewDecoder(r.Body).Decode(&pet); err != nil {
+	d := json.NewDecoder(r.Body)
+	d.DisallowUnknownFields()
+	if err := d.Decode(&pet); err != nil {
 		c.errorHandler(w, r, &ParsingError{Err: err}, nil)
 		return
 	}
-	result, err := c.service.UpdatePet(r.Context(), *pet)
+	if err := AssertPetRequired(pet); err != nil {
+		c.errorHandler(w, r, err, nil)
+		return
+	}
+	result, err := c.service.UpdatePet(r.Context(), pet)
 	// If an error occurred, encode the error with the status code
 	if err != nil {
 		c.errorHandler(w, r, err, &result)

samples/server/petstore/go-chi-server/go/api_store.go

@@ -126,12 +126,18 @@ func (c *StoreApiController) GetOrderById(w http.ResponseWriter, r *http.Request
 
 // PlaceOrder - Place an order for a pet
 func (c *StoreApiController) PlaceOrder(w http.ResponseWriter, r *http.Request) {
-	order := &Order{}
+	order := Order{}
-	if err := json.NewDecoder(r.Body).Decode(&order); err != nil {
+	d := json.NewDecoder(r.Body)
+	d.DisallowUnknownFields()
+	if err := d.Decode(&order); err != nil {
 		c.errorHandler(w, r, &ParsingError{Err: err}, nil)
 		return
 	}
-	result, err := c.service.PlaceOrder(r.Context(), *order)
+	if err := AssertOrderRequired(order); err != nil {
+		c.errorHandler(w, r, err, nil)
+		return
+	}
+	result, err := c.service.PlaceOrder(r.Context(), order)
 	// If an error occurred, encode the error with the status code
 	if err != nil {
 		c.errorHandler(w, r, err, &result)

samples/server/petstore/go-chi-server/go/api_user.go

@@ -103,12 +103,18 @@ func (c *UserApiController) Routes() Routes {
 
 // CreateUser - Create user
 func (c *UserApiController) CreateUser(w http.ResponseWriter, r *http.Request) {
-	user := &User{}
+	user := User{}
-	if err := json.NewDecoder(r.Body).Decode(&user); err != nil {
+	d := json.NewDecoder(r.Body)
+	d.DisallowUnknownFields()
+	if err := d.Decode(&user); err != nil {
 		c.errorHandler(w, r, &ParsingError{Err: err}, nil)
 		return
 	}
-	result, err := c.service.CreateUser(r.Context(), *user)
+	if err := AssertUserRequired(user); err != nil {
+		c.errorHandler(w, r, err, nil)
+		return
+	}
+	result, err := c.service.CreateUser(r.Context(), user)
 	// If an error occurred, encode the error with the status code
 	if err != nil {
 		c.errorHandler(w, r, err, &result)
@@ -121,12 +127,20 @@ func (c *UserApiController) CreateUser(w http.ResponseWriter, r *http.Request) {
 
 // CreateUsersWithArrayInput - Creates list of users with given input array
 func (c *UserApiController) CreateUsersWithArrayInput(w http.ResponseWriter, r *http.Request) {
-	user := &[]User{}
+	user := []User{}
-	if err := json.NewDecoder(r.Body).Decode(&user); err != nil {
+	d := json.NewDecoder(r.Body)
+	d.DisallowUnknownFields()
+	if err := d.Decode(&user); err != nil {
 		c.errorHandler(w, r, &ParsingError{Err: err}, nil)
 		return
 	}
-	result, err := c.service.CreateUsersWithArrayInput(r.Context(), *user)
+	for _, el := range user {
+		if err := AssertUserRequired(el); err != nil {
+			c.errorHandler(w, r, err, nil)
+			return
+		}
+	}
+	result, err := c.service.CreateUsersWithArrayInput(r.Context(), user)
 	// If an error occurred, encode the error with the status code
 	if err != nil {
 		c.errorHandler(w, r, err, &result)
@@ -139,12 +153,20 @@ func (c *UserApiController) CreateUsersWithArrayInput(w http.ResponseWriter, r *
 
 // CreateUsersWithListInput - Creates list of users with given input array
 func (c *UserApiController) CreateUsersWithListInput(w http.ResponseWriter, r *http.Request) {
-	user := &[]User{}
+	user := []User{}
-	if err := json.NewDecoder(r.Body).Decode(&user); err != nil {
+	d := json.NewDecoder(r.Body)
+	d.DisallowUnknownFields()
+	if err := d.Decode(&user); err != nil {
 		c.errorHandler(w, r, &ParsingError{Err: err}, nil)
 		return
 	}
-	result, err := c.service.CreateUsersWithListInput(r.Context(), *user)
+	for _, el := range user {
+		if err := AssertUserRequired(el); err != nil {
+			c.errorHandler(w, r, err, nil)
+			return
+		}
+	}
+	result, err := c.service.CreateUsersWithListInput(r.Context(), user)
 	// If an error occurred, encode the error with the status code
 	if err != nil {
 		c.errorHandler(w, r, err, &result)
@@ -218,12 +240,18 @@ func (c *UserApiController) LogoutUser(w http.ResponseWriter, r *http.Request) {
 func (c *UserApiController) UpdateUser(w http.ResponseWriter, r *http.Request) {
 	username := chi.URLParam(r, "username")
 	
-	user := &User{}
+	user := User{}
-	if err := json.NewDecoder(r.Body).Decode(&user); err != nil {
+	d := json.NewDecoder(r.Body)
+	d.DisallowUnknownFields()
+	if err := d.Decode(&user); err != nil {
 		c.errorHandler(w, r, &ParsingError{Err: err}, nil)
 		return
 	}
-	result, err := c.service.UpdateUser(r.Context(), username, *user)
+	if err := AssertUserRequired(user); err != nil {
+		c.errorHandler(w, r, err, nil)
+		return
+	}
+	result, err := c.service.UpdateUser(r.Context(), username, user)
 	// If an error occurred, encode the error with the status code
 	if err != nil {
 		c.errorHandler(w, r, err, &result)

samples/server/petstore/go-chi-server/go/error.go

@@ -10,9 +10,16 @@
 package petstoreserver
 
 import (
+	"errors"
+	"fmt"
 	"net/http"
 )
 
+var (
+	// ErrTypeAssertionError is thrown when type an interface does not match the asserted type
+	ErrTypeAssertionError = errors.New("unable to assert type")
+)
+
 // ParsingError indicates that an error has occurred when parsing request parameters
 type ParsingError struct {
 	Err error
@@ -26,6 +33,15 @@ func (e *ParsingError) Error() string {
 	return e.Err.Error()
 }
 
+// RequiredError indicates that an error has occurred when parsing request parameters
+type RequiredError struct {
+	Field string
+}
+
+func (e *RequiredError) Error() string {
+	return fmt.Sprintf("required field '%s' is zero value.", e.Field)
+}
+
 // ErrorHandler defines the required method for handling error. You may implement it and inject this into a controller if
 // you would like errors to be handled differently from the DefaultErrorHandler
 type ErrorHandler func(w http.ResponseWriter, r *http.Request, err error, result *ImplResponse)
@@ -36,6 +52,9 @@ func DefaultErrorHandler(w http.ResponseWriter, r *http.Request, err error, resu
 	if _, ok := err.(*ParsingError); ok {
 		// Handle parsing errors
 		EncodeJSONResponse(err.Error(), func(i int) *int { return &i }(http.StatusBadRequest), map[string][]string{}, w)
+	} else if _, ok := err.(*RequiredError); ok {
+		// Handle missing required errors
+		EncodeJSONResponse(err.Error(), func(i int) *int { return &i }(http.StatusUnprocessableEntity), map[string][]string{}, w)
 	} else {
 		// Handle all other errors
 		EncodeJSONResponse(err.Error(), &result.Code, result.Headers, w)

samples/server/petstore/go-chi-server/go/helpers.go

@@ -9,7 +9,11 @@
 
 package petstoreserver
 
-//Response return a ImplResponse struct filled
+import (
+	"reflect"
+)
+
+// Response return a ImplResponse struct filled
 func Response(code int, body interface{}) ImplResponse {
 	return ImplResponse {
 		Code: code,
@@ -18,7 +22,7 @@ func Response(code int, body interface{}) ImplResponse {
 	}
 }
 
-//ResponseWithHeaders return a ImplResponse struct filled, including headers
+// ResponseWithHeaders return a ImplResponse struct filled, including headers
 func ResponseWithHeaders(code int, headers map[string][]string, body interface{}) ImplResponse {
 	return ImplResponse {
 		Code: code,
@@ -26,3 +30,35 @@ func ResponseWithHeaders(code int, headers map[string][]string, body interface{}
 		Body: body,
 	}
 }
+
+// IsZeroValue checks if the val is the zero-ed value.
+func IsZeroValue(val interface{}) bool {
+	return val == nil || reflect.DeepEqual(val, reflect.Zero(reflect.TypeOf(val)).Interface())
+}
+
+// AssertInterfaceRequired recursively checks each struct in a slice against the callback.
+// This method traverse nested slices in a preorder fashion.
+func AssertRecurseInterfaceRequired(obj interface{}, callback func(interface{}) error) error {
+	return AssertRecurseValueRequired(reflect.ValueOf(obj), callback)
+}
+
+// AssertNestedValueRequired checks each struct in the nested slice against the callback.
+// This method traverse nested slices in a preorder fashion.
+func AssertRecurseValueRequired(value reflect.Value, callback func(interface{}) error) error {
+	switch value.Kind() {
+	// If it is a struct we check using callback
+	case reflect.Struct:
+		if err := callback(value.Interface()); err != nil {
+			return err
+		}
+
+	// If it is a slice we continue recursion
+	case reflect.Slice:
+		for i := 0; i < value.Len(); i += 1 {
+			if err := AssertRecurseValueRequired(value.Index(i), callback); err != nil {
+				return err
+			}
+		}
+	}
+	return nil
+}

samples/server/petstore/go-chi-server/go/model_api_response.go

@@ -18,3 +18,20 @@ type ApiResponse struct {
 
 	Message string `json:"message,omitempty"`
 }
+
+// AssertApiResponseRequired checks if the required fields are not zero-ed
+func AssertApiResponseRequired(obj ApiResponse) error {
+	return nil
+}
+
+// AssertRecurseApiResponseRequired recursively checks if required fields are not zero-ed in a nested slice.
+// Accepts only nested slice of ApiResponse (e.g. [][]ApiResponse), otherwise ErrTypeAssertionError is thrown.
+func AssertRecurseApiResponseRequired(objSlice interface{}) error {
+	return AssertRecurseInterfaceRequired(objSlice, func(obj interface{}) error {
+		aApiResponse, ok := obj.(ApiResponse)
+		if !ok {
+			return ErrTypeAssertionError
+		}
+		return AssertApiResponseRequired(aApiResponse)
+	})
+}

samples/server/petstore/go-chi-server/go/model_category.go

@@ -16,3 +16,20 @@ type Category struct {
 
 	Name string `json:"name,omitempty"`
 }
+
+// AssertCategoryRequired checks if the required fields are not zero-ed
+func AssertCategoryRequired(obj Category) error {
+	return nil
+}
+
+// AssertRecurseCategoryRequired recursively checks if required fields are not zero-ed in a nested slice.
+// Accepts only nested slice of Category (e.g. [][]Category), otherwise ErrTypeAssertionError is thrown.
+func AssertRecurseCategoryRequired(objSlice interface{}) error {
+	return AssertRecurseInterfaceRequired(objSlice, func(obj interface{}) error {
+		aCategory, ok := obj.(Category)
+		if !ok {
+			return ErrTypeAssertionError
+		}
+		return AssertCategoryRequired(aCategory)
+	})
+}

samples/server/petstore/go-chi-server/go/model_order.go

@@ -29,3 +29,20 @@ type Order struct {
 
 	Complete bool `json:"complete,omitempty"`
 }
+
+// AssertOrderRequired checks if the required fields are not zero-ed
+func AssertOrderRequired(obj Order) error {
+	return nil
+}
+
+// AssertRecurseOrderRequired recursively checks if required fields are not zero-ed in a nested slice.
+// Accepts only nested slice of Order (e.g. [][]Order), otherwise ErrTypeAssertionError is thrown.
+func AssertRecurseOrderRequired(objSlice interface{}) error {
+	return AssertRecurseInterfaceRequired(objSlice, func(obj interface{}) error {
+		aOrder, ok := obj.(Order)
+		if !ok {
+			return ErrTypeAssertionError
+		}
+		return AssertOrderRequired(aOrder)
+	})
+}

samples/server/petstore/go-chi-server/go/model_pet.go

@@ -26,3 +26,38 @@ type Pet struct {
 	// Deprecated
 	Status string `json:"status,omitempty"`
 }
+
+// AssertPetRequired checks if the required fields are not zero-ed
+func AssertPetRequired(obj Pet) error {
+	elements := map[string]interface{}{
+		"name": obj.Name,
+		"photoUrls": obj.PhotoUrls,
+	}
+	for name, el := range elements {
+		if isZero := IsZeroValue(el); isZero {
+			return &RequiredError{Field: name}
+		}
+	}
+
+	if err := AssertCategoryRequired(obj.Category); err != nil {
+		return err
+	}
+	for _, el := range obj.Tags {
+		if err := AssertTagRequired(el); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+// AssertRecursePetRequired recursively checks if required fields are not zero-ed in a nested slice.
+// Accepts only nested slice of Pet (e.g. [][]Pet), otherwise ErrTypeAssertionError is thrown.
+func AssertRecursePetRequired(objSlice interface{}) error {
+	return AssertRecurseInterfaceRequired(objSlice, func(obj interface{}) error {
+		aPet, ok := obj.(Pet)
+		if !ok {
+			return ErrTypeAssertionError
+		}
+		return AssertPetRequired(aPet)
+	})
+}

samples/server/petstore/go-chi-server/go/model_tag.go

@@ -16,3 +16,20 @@ type Tag struct {
 
 	Name string `json:"name,omitempty"`
 }
+
+// AssertTagRequired checks if the required fields are not zero-ed
+func AssertTagRequired(obj Tag) error {
+	return nil
+}
+
+// AssertRecurseTagRequired recursively checks if required fields are not zero-ed in a nested slice.
+// Accepts only nested slice of Tag (e.g. [][]Tag), otherwise ErrTypeAssertionError is thrown.
+func AssertRecurseTagRequired(objSlice interface{}) error {
+	return AssertRecurseInterfaceRequired(objSlice, func(obj interface{}) error {
+		aTag, ok := obj.(Tag)
+		if !ok {
+			return ErrTypeAssertionError
+		}
+		return AssertTagRequired(aTag)
+	})
+}

samples/server/petstore/go-chi-server/go/model_user.go

@@ -29,3 +29,20 @@ type User struct {
 	// User Status
 	UserStatus int32 `json:"userStatus,omitempty"`
 }
+
+// AssertUserRequired checks if the required fields are not zero-ed
+func AssertUserRequired(obj User) error {
+	return nil
+}
+
+// AssertRecurseUserRequired recursively checks if required fields are not zero-ed in a nested slice.
+// Accepts only nested slice of User (e.g. [][]User), otherwise ErrTypeAssertionError is thrown.
+func AssertRecurseUserRequired(objSlice interface{}) error {
+	return AssertRecurseInterfaceRequired(objSlice, func(obj interface{}) error {
+		aUser, ok := obj.(User)
+		if !ok {
+			return ErrTypeAssertionError
+		}
+		return AssertUserRequired(aUser)
+	})
+}

samples/server/petstore/go-server-required/.openapi-generator-ignore

@@ -0,0 +1,23 @@
+# OpenAPI Generator Ignore
+# Generated by openapi-generator https://github.com/openapitools/openapi-generator
+
+# Use this file to prevent files from being overwritten by the generator.
+# The patterns follow closely to .gitignore or .dockerignore.
+
+# As an example, the C# client generator defines ApiClient.cs.
+# You can make changes and tell OpenAPI Generator to ignore just this file by uncommenting the following line:
+#ApiClient.cs
+
+# You can match any string of characters against a directory, file or extension with a single asterisk (*):
+#foo/*/qux
+# The above matches foo/bar/qux and foo/baz/qux, but not foo/bar/baz/qux
+
+# You can recursively match patterns against a directory, file or extension with a double asterisk (**):
+#foo/**/qux
+# This matches foo/bar/qux, foo/baz/qux, and foo/bar/baz/qux
+
+# You can also negate patterns with an exclamation (!).
+# For example, you can ignore all files in a docs folder with the file extension .md:
+#docs/*.md
+# Then explicitly reverse the ignore rule for a single file:
+#!docs/README.md

samples/server/petstore/go-server-required/.openapi-generator/FILES

@@ -0,0 +1,25 @@
+Dockerfile
+README.md
+api/openapi.yaml
+go.mod
+go/api.go
+go/api_pet.go
+go/api_pet_service.go
+go/api_store.go
+go/api_store_service.go
+go/api_user.go
+go/api_user_service.go
+go/error.go
+go/helpers.go
+go/impl.go
+go/logger.go
+go/model_api_response.go
+go/model_category.go
+go/model_order.go
+go/model_order_info.go
+go/model_pet.go
+go/model_special_info.go
+go/model_tag.go
+go/model_user.go
+go/routers.go
+main.go

samples/server/petstore/go-server-required/.openapi-generator/VERSION

@@ -0,0 +1 @@
+5.2.1-SNAPSHOT

samples/server/petstore/go-server-required/Dockerfile

@@ -0,0 +1,14 @@
+FROM golang:1.10 AS build
+WORKDIR /go/src
+COPY go ./go
+COPY main.go .
+
+ENV CGO_ENABLED=0
+RUN go get -d -v ./...
+
+RUN go build -a -installsuffix cgo -o petstoreserver .
+
+FROM scratch AS runtime
+COPY --from=build /go/src/petstoreserver ./
+EXPOSE 8080/tcp
+ENTRYPOINT ["./petstoreserver"]

samples/server/petstore/go-server-required/README.md

@@ -0,0 +1,35 @@
+# Go API Server for petstoreserver
+
+This is a sample server Petstore server. For this sample, you can use the api key `special-key` to test the authorization filters.
+
+## Overview
+This server was generated by the [openapi-generator]
+(https://openapi-generator.tech) project.
+By using the [OpenAPI-Spec](https://github.com/OAI/OpenAPI-Specification) from a remote server, you can easily generate a server stub.  
+-
+
+To see how to make this your own, look here:
+
+[README](https://openapi-generator.tech)
+
+- API version: 1.0.0
+
+
+### Running the server
+To run the server, follow these simple steps:
+
+```
+go run main.go
+```
+
+To run the server in a docker container
+```
+docker build --network=host -t petstoreserver .
+```
+
+Once image is built use
+```
+docker run --rm -it petstoreserver 
+```
+
+

samples/server/petstore/go-server-required/api/openapi.yaml

@@ -0,0 +1,906 @@
+openapi: 3.0.0
+info:
+  description: This is a sample server Petstore server. For this sample, you can use
+    the api key `special-key` to test the authorization filters.
+  license:
+    name: Apache-2.0
+    url: https://www.apache.org/licenses/LICENSE-2.0.html
+  title: OpenAPI Petstore
+  version: 1.0.0
+externalDocs:
+  description: Find out more about Swagger
+  url: http://swagger.io
+servers:
+- url: http://petstore.swagger.io/v2
+tags:
+- description: Everything about your Pets
+  name: pet
+- description: Access to Petstore orders
+  name: store
+- description: Operations about user
+  name: user
+paths:
+  /pet:
+    post:
+      operationId: addPet
+      requestBody:
+        $ref: '#/components/requestBodies/Pet'
+      responses:
+        "200":
+          content:
+            application/xml:
+              schema:
+                $ref: '#/components/schemas/Pet'
+            application/json:
+              schema:
+                $ref: '#/components/schemas/Pet'
+          description: successful operation
+        "405":
+          description: Invalid input
+      security:
+      - petstore_auth:
+        - write:pets
+        - read:pets
+      summary: Add a new pet to the store
+      tags:
+      - pet
+    put:
+      operationId: updatePet
+      requestBody:
+        $ref: '#/components/requestBodies/Pet'
+      responses:
+        "200":
+          content:
+            application/xml:
+              schema:
+                $ref: '#/components/schemas/Pet'
+            application/json:
+              schema:
+                $ref: '#/components/schemas/Pet'
+          description: successful operation
+        "400":
+          description: Invalid ID supplied
+        "404":
+          description: Pet not found
+        "405":
+          description: Validation exception
+      security:
+      - petstore_auth:
+        - write:pets
+        - read:pets
+      summary: Update an existing pet
+      tags:
+      - pet
+  /pet/findByStatus:
+    get:
+      description: Multiple status values can be provided with comma separated strings
+      operationId: findPetsByStatus
+      parameters:
+      - description: Status values that need to be considered for filter
+        explode: false
+        in: query
+        name: status
+        required: true
+        schema:
+          items:
+            default: available
+            enum:
+            - available
+            - pending
+            - sold
+            type: string
+          type: array
+        style: form
+      responses:
+        "200":
+          content:
+            application/xml:
+              schema:
+                items:
+                  $ref: '#/components/schemas/Pet'
+                type: array
+            application/json:
+              schema:
+                items:
+                  $ref: '#/components/schemas/Pet'
+                type: array
+          description: successful operation
+        "400":
+          description: Invalid status value
+      security:
+      - petstore_auth:
+        - read:pets
+      summary: Finds Pets by status
+      tags:
+      - pet
+  /pet/findByTags:
+    get:
+      deprecated: true
+      description: Multiple tags can be provided with comma separated strings. Use
+        tag1, tag2, tag3 for testing.
+      operationId: findPetsByTags
+      parameters:
+      - description: Tags to filter by
+        explode: false
+        in: query
+        name: tags
+        required: true
+        schema:
+          items:
+            type: string
+          type: array
+        style: form
+      responses:
+        "200":
+          content:
+            application/xml:
+              schema:
+                items:
+                  $ref: '#/components/schemas/Pet'
+                type: array
+            application/json:
+              schema:
+                items:
+                  $ref: '#/components/schemas/Pet'
+                type: array
+          description: successful operation
+        "400":
+          description: Invalid tag value
+      security:
+      - petstore_auth:
+        - read:pets
+      summary: Finds Pets by tags
+      tags:
+      - pet
+  /pet/{petId}:
+    delete:
+      operationId: deletePet
+      parameters:
+      - explode: false
+        in: header
+        name: api_key
+        required: false
+        schema:
+          type: string
+        style: simple
+      - description: Pet id to delete
+        explode: false
+        in: path
+        name: petId
+        required: true
+        schema:
+          format: int64
+          type: integer
+        style: simple
+      responses:
+        "400":
+          description: Invalid pet value
+      security:
+      - petstore_auth:
+        - write:pets
+        - read:pets
+      summary: Deletes a pet
+      tags:
+      - pet
+    get:
+      description: Returns a single pet
+      operationId: getPetById
+      parameters:
+      - description: ID of pet to return
+        explode: false
+        in: path
+        name: petId
+        required: true
+        schema:
+          format: int64
+          type: integer
+        style: simple
+      responses:
+        "200":
+          content:
+            application/xml:
+              schema:
+                $ref: '#/components/schemas/Pet'
+            application/json:
+              schema:
+                $ref: '#/components/schemas/Pet'
+          description: successful operation
+        "400":
+          description: Invalid ID supplied
+        "404":
+          description: Pet not found
+      security:
+      - api_key: []
+      summary: Find pet by ID
+      tags:
+      - pet
+    post:
+      operationId: updatePetWithForm
+      parameters:
+      - description: ID of pet that needs to be updated
+        explode: false
+        in: path
+        name: petId
+        required: true
+        schema:
+          format: int64
+          type: integer
+        style: simple
+      requestBody:
+        $ref: '#/components/requestBodies/inline_object'
+        content:
+          application/x-www-form-urlencoded:
+            schema:
+              properties:
+                name:
+                  description: Updated name of the pet
+                  type: string
+                status:
+                  description: Updated status of the pet
+                  type: string
+              type: object
+      responses:
+        "405":
+          description: Invalid input
+      security:
+      - petstore_auth:
+        - write:pets
+        - read:pets
+      summary: Updates a pet in the store with form data
+      tags:
+      - pet
+  /pet/{petId}/uploadImage:
+    post:
+      operationId: uploadFile
+      parameters:
+      - description: ID of pet to update
+        explode: false
+        in: path
+        name: petId
+        required: true
+        schema:
+          format: int64
+          type: integer
+        style: simple
+      requestBody:
+        $ref: '#/components/requestBodies/inline_object_1'
+        content:
+          multipart/form-data:
+            schema:
+              properties:
+                additionalMetadata:
+                  description: Additional data to pass to server
+                  type: string
+                file:
+                  description: file to upload
+                  format: binary
+                  type: string
+              type: object
+      responses:
+        "200":
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/ApiResponse'
+          description: successful operation
+      security:
+      - petstore_auth:
+        - write:pets
+        - read:pets
+      summary: uploads an image
+      tags:
+      - pet
+  /store/inventory:
+    get:
+      description: Returns a map of status codes to quantities
+      operationId: getInventory
+      responses:
+        "200":
+          content:
+            application/json:
+              schema:
+                additionalProperties:
+                  format: int32
+                  type: integer
+                type: object
+          description: successful operation
+      security:
+      - api_key: []
+      summary: Returns pet inventories by status
+      tags:
+      - store
+  /store/order:
+    post:
+      operationId: placeOrder
+      requestBody:
+        content:
+          application/json:
+            schema:
+              $ref: '#/components/schemas/Order'
+        description: order placed for purchasing the pet
+        required: true
+      responses:
+        "200":
+          content:
+            application/xml:
+              schema:
+                $ref: '#/components/schemas/Order'
+            application/json:
+              schema:
+                $ref: '#/components/schemas/Order'
+          description: successful operation
+        "400":
+          description: Invalid Order
+      summary: Place an order for a pet
+      tags:
+      - store
+  /store/order/{orderId}:
+    delete:
+      description: For valid response try integer IDs with value < 1000. Anything
+        above 1000 or nonintegers will generate API errors
+      operationId: deleteOrder
+      parameters:
+      - description: ID of the order that needs to be deleted
+        explode: false
+        in: path
+        name: orderId
+        required: true
+        schema:
+          type: string
+        style: simple
+      responses:
+        "400":
+          description: Invalid ID supplied
+        "404":
+          description: Order not found
+      summary: Delete purchase order by ID
+      tags:
+      - store
+    get:
+      description: For valid response try integer IDs with value <= 5 or > 10. Other
+        values will generated exceptions
+      operationId: getOrderById
+      parameters:
+      - description: ID of pet that needs to be fetched
+        explode: false
+        in: path
+        name: orderId
+        required: true
+        schema:
+          format: int64
+          maximum: 5
+          minimum: 1
+          type: integer
+        style: simple
+      responses:
+        "200":
+          content:
+            application/xml:
+              schema:
+                $ref: '#/components/schemas/Order'
+            application/json:
+              schema:
+                $ref: '#/components/schemas/Order'
+          description: successful operation
+        "400":
+          description: Invalid ID supplied
+        "404":
+          description: Order not found
+      summary: Find purchase order by ID
+      tags:
+      - store
+  /user:
+    post:
+      description: This can only be done by the logged in user.
+      operationId: createUser
+      requestBody:
+        content:
+          application/json:
+            schema:
+              $ref: '#/components/schemas/User'
+        description: Created user object
+        required: true
+      responses:
+        default:
+          description: successful operation
+      security:
+      - api_key: []
+      summary: Create user
+      tags:
+      - user
+  /user/createWithArray:
+    post:
+      operationId: createUsersWithArrayInput
+      requestBody:
+        $ref: '#/components/requestBodies/UserArray'
+      responses:
+        default:
+          description: successful operation
+      security:
+      - api_key: []
+      summary: Creates list of users with given input array
+      tags:
+      - user
+  /user/createWithList:
+    post:
+      operationId: createUsersWithListInput
+      requestBody:
+        $ref: '#/components/requestBodies/UserArray'
+      responses:
+        default:
+          description: successful operation
+      security:
+      - api_key: []
+      summary: Creates list of users with given input array
+      tags:
+      - user
+  /user/login:
+    get:
+      operationId: loginUser
+      parameters:
+      - description: The user name for login
+        explode: true
+        in: query
+        name: username
+        required: true
+        schema:
+          pattern: ^[a-zA-Z0-9]+[a-zA-Z0-9\.\-_]*[a-zA-Z0-9]+$
+          type: string
+        style: form
+      - description: The password for login in clear text
+        explode: true
+        in: query
+        name: password
+        required: true
+        schema:
+          type: string
+        style: form
+      responses:
+        "200":
+          content:
+            application/xml:
+              schema:
+                type: string
+            application/json:
+              schema:
+                type: string
+          description: successful operation
+          headers:
+            Set-Cookie:
+              description: Cookie authentication key for use with the `api_key` apiKey
+                authentication.
+              explode: false
+              schema:
+                example: AUTH_KEY=abcde12345; Path=/; HttpOnly
+                type: string
+              style: simple
+            X-Rate-Limit:
+              description: calls per hour allowed by the user
+              explode: false
+              schema:
+                format: int32
+                type: integer
+              style: simple
+            X-Expires-After:
+              description: date in UTC when toekn expires
+              explode: false
+              schema:
+                format: date-time
+                type: string
+              style: simple
+        "400":
+          description: Invalid username/password supplied
+      summary: Logs user into the system
+      tags:
+      - user
+  /user/logout:
+    get:
+      operationId: logoutUser
+      responses:
+        default:
+          description: successful operation
+      security:
+      - api_key: []
+      summary: Logs out current logged in user session
+      tags:
+      - user
+  /user/{username}:
+    delete:
+      description: This can only be done by the logged in user.
+      operationId: deleteUser
+      parameters:
+      - description: The name that needs to be deleted
+        explode: false
+        in: path
+        name: username
+        required: true
+        schema:
+          type: string
+        style: simple
+      responses:
+        "400":
+          description: Invalid username supplied
+        "404":
+          description: User not found
+      security:
+      - api_key: []
+      summary: Delete user
+      tags:
+      - user
+    get:
+      operationId: getUserByName
+      parameters:
+      - description: The name that needs to be fetched. Use user1 for testing.
+        explode: false
+        in: path
+        name: username
+        required: true
+        schema:
+          type: string
+        style: simple
+      responses:
+        "200":
+          content:
+            application/xml:
+              schema:
+                $ref: '#/components/schemas/User'
+            application/json:
+              schema:
+                $ref: '#/components/schemas/User'
+          description: successful operation
+        "400":
+          description: Invalid username supplied
+        "404":
+          description: User not found
+      summary: Get user by user name
+      tags:
+      - user
+    put:
+      description: This can only be done by the logged in user.
+      operationId: updateUser
+      parameters:
+      - description: name that need to be deleted
+        explode: false
+        in: path
+        name: username
+        required: true
+        schema:
+          type: string
+        style: simple
+      requestBody:
+        content:
+          application/json:
+            schema:
+              $ref: '#/components/schemas/User'
+        description: Updated user object
+        required: true
+      responses:
+        "400":
+          description: Invalid user supplied
+        "404":
+          description: User not found
+      security:
+      - api_key: []
+      summary: Updated user
+      tags:
+      - user
+components:
+  requestBodies:
+    UserArray:
+      content:
+        application/json:
+          schema:
+            items:
+              $ref: '#/components/schemas/User'
+            type: array
+      description: List of user object
+      required: true
+    Pet:
+      content:
+        application/json:
+          schema:
+            $ref: '#/components/schemas/Pet'
+        application/xml:
+          schema:
+            $ref: '#/components/schemas/Pet'
+      description: Pet object that needs to be added to the store
+      required: true
+    inline_object:
+      content:
+        application/x-www-form-urlencoded:
+          schema:
+            $ref: '#/components/schemas/inline_object'
+    inline_object_1:
+      content:
+        multipart/form-data:
+          schema:
+            $ref: '#/components/schemas/inline_object_1'
+  schemas:
+    OrderInfo:
+      description: An order info for a pets from the pet store
+      properties:
+        petId:
+          format: int64
+          type: integer
+        quantity:
+          format: int32
+          type: integer
+        shipDate:
+          format: date-time
+          type: string
+      title: Pet Order Info
+      type: object
+      xml:
+        name: OrderInfo
+    SpecialInfo:
+      description: An order info for a pets from the pet store
+      discriminator:
+        propertyName: type
+      properties:
+        promotion:
+          type: boolean
+        type:
+          type: string
+      title: Pet Order Info
+      type: object
+      xml:
+        name: OrderInfo
+    Order:
+      allOf:
+      - $ref: '#/components/schemas/OrderInfo'
+      - $ref: '#/components/schemas/SpecialInfo'
+      description: An order for a pets from the pet store
+      example:
+        comment: comment
+        id: 0
+        complete: false
+        status: placed
+      properties:
+        id:
+          format: int64
+          type: integer
+        status:
+          description: Order Status
+          enum:
+          - placed
+          - approved
+          - delivered
+          type: string
+        complete:
+          default: false
+          type: boolean
+        comment:
+          nullable: true
+          type: string
+      required:
+      - comment
+      title: Pet Order
+      type: object
+      xml:
+        name: Order
+    Category:
+      description: A category for a pet
+      example:
+        name: name
+        id: 6
+      nullable: true
+      properties:
+        id:
+          format: int64
+          type: integer
+        name:
+          pattern: ^[a-zA-Z0-9]+[a-zA-Z0-9\.\-_]*[a-zA-Z0-9]+$
+          type: string
+      title: Pet category
+      type: object
+      xml:
+        name: Category
+    User:
+      description: A User who is purchasing from the pet store
+      example:
+        firstName: firstName
+        lastName: lastName
+        password: password
+        userStatus: 6
+        phone: phone
+        deepSliceModel:
+        - - - name: name
+              id: 1
+            - name: name
+              id: 1
+          - - name: name
+              id: 1
+            - name: name
+              id: 1
+        - - - name: name
+              id: 1
+            - name: name
+              id: 1
+          - - name: name
+              id: 1
+            - name: name
+              id: 1
+        id: 0
+        deepSliceMap:
+        - - '{}'
+          - '{}'
+        - - '{}'
+          - '{}'
+        email: email
+        username: username
+      properties:
+        id:
+          format: int64
+          type: integer
+        username:
+          type: string
+        firstName:
+          type: string
+        lastName:
+          type: string
+        email:
+          type: string
+        password:
+          type: string
+        phone:
+          nullable: true
+          type: string
+        userStatus:
+          description: User Status
+          format: int32
+          type: integer
+        deepSliceModel:
+          description: An array 1-deep.
+          items:
+            description: An array 2-deep.
+            items:
+              description: An array 3-deep.
+              items:
+                $ref: '#/components/schemas/Tag'
+              type: array
+            type: array
+          nullable: true
+          type: array
+        deepSliceMap:
+          description: An array 1-deep.
+          items:
+            description: An array 2-deep.
+            items:
+              description: An array 3-deep.
+              properties:
+                tag:
+                  $ref: '#/components/schemas/Tag'
+                Pet:
+                  description: An array of pet.
+                  items:
+                    $ref: '#/components/schemas/Pet'
+                  type: array
+              title: an Object
+              type: object
+            type: array
+          type: array
+      required:
+      - deepSliceModel
+      title: a User
+      type: object
+      xml:
+        name: User
+    Tag:
+      description: A tag for a pet
+      example:
+        name: name
+        id: 1
+      properties:
+        id:
+          format: int64
+          type: integer
+        name:
+          type: string
+      title: Pet Tag
+      type: object
+      xml:
+        name: Tag
+    Pet:
+      description: A pet for sale in the pet store
+      example:
+        photoUrls:
+        - photoUrls
+        - photoUrls
+        name: doggie
+        id: 0
+        category:
+          name: name
+          id: 6
+        tags:
+        - name: name
+          id: 1
+        - name: name
+          id: 1
+        status: available
+      properties:
+        id:
+          format: int64
+          type: integer
+        category:
+          $ref: '#/components/schemas/Category'
+        name:
+          example: doggie
+          type: string
+        photoUrls:
+          items:
+            type: string
+          nullable: true
+          type: array
+          xml:
+            name: photoUrl
+            wrapped: true
+        tags:
+          items:
+            $ref: '#/components/schemas/Tag'
+          nullable: true
+          type: array
+          xml:
+            name: tag
+            wrapped: true
+        status:
+          description: pet status in the store
+          enum:
+          - available
+          - pending
+          - sold
+          type: string
+      required:
+      - name
+      - photoUrls
+      title: a Pet
+      type: object
+      xml:
+        name: Pet
+    ApiResponse:
+      description: Describes the result of uploading an image resource
+      example:
+        code: 0
+        type: type
+        message: message
+      properties:
+        code:
+          format: int32
+          type: integer
+        type:
+          type: string
+        message:
+          type: string
+      title: An uploaded response
+      type: object
+    inline_object:
+      properties:
+        name:
+          description: Updated name of the pet
+          type: string
+        status:
+          description: Updated status of the pet
+          type: string
+      type: object
+    inline_object_1:
+      properties:
+        additionalMetadata:
+          description: Additional data to pass to server
+          type: string
+        file:
+          description: file to upload
+          format: binary
+          type: string
+      type: object
+  securitySchemes:
+    petstore_auth:
+      flows:
+        implicit:
+          authorizationUrl: http://petstore.swagger.io/api/oauth/dialog
+          scopes:
+            write:pets: modify pets in your account
+            read:pets: read your pets
+      type: oauth2
+    api_key:
+      in: header
+      name: api_key
+      type: apiKey

samples/server/petstore/go-server-required/go.mod

@@ -0,0 +1,5 @@
+module github.com/GIT_USER_ID/GIT_REPO_ID
+
+go 1.13
+
+require github.com/go-chi/chi/v5 v5.0.3

samples/server/petstore/go-server-required/go/api.go

@@ -0,0 +1,100 @@
+/*
+ * OpenAPI Petstore
+ *
+ * This is a sample server Petstore server. For this sample, you can use the api key `special-key` to test the authorization filters.
+ *
+ * API version: 1.0.0
+ * Generated by: OpenAPI Generator (https://openapi-generator.tech)
+ */
+
+package petstoreserver
+
+import (
+	"context"
+	"net/http"
+	"os"
+)
+
+
+
+// PetApiRouter defines the required methods for binding the api requests to a responses for the PetApi
+// The PetApiRouter implementation should parse necessary information from the http request, 
+// pass the data to a PetApiServicer to perform the required actions, then write the service results to the http response.
+type PetApiRouter interface { 
+	AddPet(http.ResponseWriter, *http.Request)
+	DeletePet(http.ResponseWriter, *http.Request)
+	FindPetsByStatus(http.ResponseWriter, *http.Request)
+	// Deprecated
+	FindPetsByTags(http.ResponseWriter, *http.Request)
+	GetPetById(http.ResponseWriter, *http.Request)
+	UpdatePet(http.ResponseWriter, *http.Request)
+	UpdatePetWithForm(http.ResponseWriter, *http.Request)
+	UploadFile(http.ResponseWriter, *http.Request)
+}
+// StoreApiRouter defines the required methods for binding the api requests to a responses for the StoreApi
+// The StoreApiRouter implementation should parse necessary information from the http request, 
+// pass the data to a StoreApiServicer to perform the required actions, then write the service results to the http response.
+type StoreApiRouter interface { 
+	DeleteOrder(http.ResponseWriter, *http.Request)
+	GetInventory(http.ResponseWriter, *http.Request)
+	GetOrderById(http.ResponseWriter, *http.Request)
+	PlaceOrder(http.ResponseWriter, *http.Request)
+}
+// UserApiRouter defines the required methods for binding the api requests to a responses for the UserApi
+// The UserApiRouter implementation should parse necessary information from the http request, 
+// pass the data to a UserApiServicer to perform the required actions, then write the service results to the http response.
+type UserApiRouter interface { 
+	CreateUser(http.ResponseWriter, *http.Request)
+	CreateUsersWithArrayInput(http.ResponseWriter, *http.Request)
+	CreateUsersWithListInput(http.ResponseWriter, *http.Request)
+	DeleteUser(http.ResponseWriter, *http.Request)
+	GetUserByName(http.ResponseWriter, *http.Request)
+	LoginUser(http.ResponseWriter, *http.Request)
+	LogoutUser(http.ResponseWriter, *http.Request)
+	UpdateUser(http.ResponseWriter, *http.Request)
+}
+
+
+// PetApiServicer defines the api actions for the PetApi service
+// This interface intended to stay up to date with the openapi yaml used to generate it, 
+// while the service implementation can ignored with the .openapi-generator-ignore file 
+// and updated with the logic required for the API.
+type PetApiServicer interface { 
+	AddPet(context.Context, Pet) (ImplResponse, error)
+	DeletePet(context.Context, int64, string) (ImplResponse, error)
+	FindPetsByStatus(context.Context, []string) (ImplResponse, error)
+	// Deprecated
+	FindPetsByTags(context.Context, []string) (ImplResponse, error)
+	GetPetById(context.Context, int64) (ImplResponse, error)
+	UpdatePet(context.Context, Pet) (ImplResponse, error)
+	UpdatePetWithForm(context.Context, int64, string, string) (ImplResponse, error)
+	UploadFile(context.Context, int64, string, *os.File) (ImplResponse, error)
+}
+
+
+// StoreApiServicer defines the api actions for the StoreApi service
+// This interface intended to stay up to date with the openapi yaml used to generate it, 
+// while the service implementation can ignored with the .openapi-generator-ignore file 
+// and updated with the logic required for the API.
+type StoreApiServicer interface { 
+	DeleteOrder(context.Context, string) (ImplResponse, error)
+	GetInventory(context.Context) (ImplResponse, error)
+	GetOrderById(context.Context, int64) (ImplResponse, error)
+	PlaceOrder(context.Context, Order) (ImplResponse, error)
+}
+
+
+// UserApiServicer defines the api actions for the UserApi service
+// This interface intended to stay up to date with the openapi yaml used to generate it, 
+// while the service implementation can ignored with the .openapi-generator-ignore file 
+// and updated with the logic required for the API.
+type UserApiServicer interface { 
+	CreateUser(context.Context, User) (ImplResponse, error)
+	CreateUsersWithArrayInput(context.Context, []User) (ImplResponse, error)
+	CreateUsersWithListInput(context.Context, []User) (ImplResponse, error)
+	DeleteUser(context.Context, string) (ImplResponse, error)
+	GetUserByName(context.Context, string) (ImplResponse, error)
+	LoginUser(context.Context, string, string) (ImplResponse, error)
+	LogoutUser(context.Context) (ImplResponse, error)
+	UpdateUser(context.Context, string, User) (ImplResponse, error)
+}

samples/server/petstore/go-server-required/go/api_pet.go

@@ -0,0 +1,275 @@
+/*
+ * OpenAPI Petstore
+ *
+ * This is a sample server Petstore server. For this sample, you can use the api key `special-key` to test the authorization filters.
+ *
+ * API version: 1.0.0
+ * Generated by: OpenAPI Generator (https://openapi-generator.tech)
+ */
+
+package petstoreserver
+
+import (
+	"encoding/json"
+	"net/http"
+	"strings"
+
+	"github.com/go-chi/chi/v5"
+)
+
+// PetApiController binds http requests to an api service and writes the service results to the http response
+type PetApiController struct {
+	service PetApiServicer
+	errorHandler ErrorHandler
+}
+
+// PetApiOption for how the controller is set up.
+type PetApiOption func(*PetApiController)
+
+// WithPetApiErrorHandler inject ErrorHandler into controller
+func WithPetApiErrorHandler(h ErrorHandler) PetApiOption {
+	return func(c *PetApiController) {
+		c.errorHandler = h
+	}
+}
+
+// NewPetApiController creates a default api controller
+func NewPetApiController(s PetApiServicer, opts ...PetApiOption) Router {
+	controller := &PetApiController{
+		service:      s,
+		errorHandler: DefaultErrorHandler,
+	}
+
+	for _, opt := range opts {
+		opt(controller)
+	}
+
+	return controller
+}
+
+// Routes returns all of the api route for the PetApiController
+func (c *PetApiController) Routes() Routes {
+	return Routes{ 
+		{
+			"AddPet",
+			strings.ToUpper("Post"),
+			"/v2/pet",
+			c.AddPet,
+		},
+		{
+			"DeletePet",
+			strings.ToUpper("Delete"),
+			"/v2/pet/{petId}",
+			c.DeletePet,
+		},
+		{
+			"FindPetsByStatus",
+			strings.ToUpper("Get"),
+			"/v2/pet/findByStatus",
+			c.FindPetsByStatus,
+		},
+		{
+			"FindPetsByTags",
+			strings.ToUpper("Get"),
+			"/v2/pet/findByTags",
+			c.FindPetsByTags,
+		},
+		{
+			"GetPetById",
+			strings.ToUpper("Get"),
+			"/v2/pet/{petId}",
+			c.GetPetById,
+		},
+		{
+			"UpdatePet",
+			strings.ToUpper("Put"),
+			"/v2/pet",
+			c.UpdatePet,
+		},
+		{
+			"UpdatePetWithForm",
+			strings.ToUpper("Post"),
+			"/v2/pet/{petId}",
+			c.UpdatePetWithForm,
+		},
+		{
+			"UploadFile",
+			strings.ToUpper("Post"),
+			"/v2/pet/{petId}/uploadImage",
+			c.UploadFile,
+		},
+	}
+}
+
+// AddPet - Add a new pet to the store
+func (c *PetApiController) AddPet(w http.ResponseWriter, r *http.Request) {
+	pet := Pet{}
+	d := json.NewDecoder(r.Body)
+	d.DisallowUnknownFields()
+	if err := d.Decode(&pet); err != nil {
+		c.errorHandler(w, r, &ParsingError{Err: err}, nil)
+		return
+	}
+	if err := AssertPetRequired(pet); err != nil {
+		c.errorHandler(w, r, err, nil)
+		return
+	}
+	result, err := c.service.AddPet(r.Context(), pet)
+	// If an error occurred, encode the error with the status code
+	if err != nil {
+		c.errorHandler(w, r, err, &result)
+		return
+	}
+	// If no error, encode the body and the result code
+	EncodeJSONResponse(result.Body, &result.Code, result.Headers, w)
+
+}
+
+// DeletePet - Deletes a pet
+func (c *PetApiController) DeletePet(w http.ResponseWriter, r *http.Request) {
+	petId, err := parseInt64Parameter(chi.URLParam(r, "petId"), true)
+	if err != nil {
+		c.errorHandler(w, r, &ParsingError{Err: err}, nil)
+		return
+	}
+
+	apiKey := r.Header.Get("api_key")
+	result, err := c.service.DeletePet(r.Context(), petId, apiKey)
+	// If an error occurred, encode the error with the status code
+	if err != nil {
+		c.errorHandler(w, r, err, &result)
+		return
+	}
+	// If no error, encode the body and the result code
+	EncodeJSONResponse(result.Body, &result.Code, result.Headers, w)
+
+}
+
+// FindPetsByStatus - Finds Pets by status
+func (c *PetApiController) FindPetsByStatus(w http.ResponseWriter, r *http.Request) {
+	query := r.URL.Query()
+	status := strings.Split(query.Get("status"), ",")
+	result, err := c.service.FindPetsByStatus(r.Context(), status)
+	// If an error occurred, encode the error with the status code
+	if err != nil {
+		c.errorHandler(w, r, err, &result)
+		return
+	}
+	// If no error, encode the body and the result code
+	EncodeJSONResponse(result.Body, &result.Code, result.Headers, w)
+
+}
+
+// FindPetsByTags - Finds Pets by tags
+// Deprecated
+func (c *PetApiController) FindPetsByTags(w http.ResponseWriter, r *http.Request) {
+	query := r.URL.Query()
+	tags := strings.Split(query.Get("tags"), ",")
+	result, err := c.service.FindPetsByTags(r.Context(), tags)
+	// If an error occurred, encode the error with the status code
+	if err != nil {
+		c.errorHandler(w, r, err, &result)
+		return
+	}
+	// If no error, encode the body and the result code
+	EncodeJSONResponse(result.Body, &result.Code, result.Headers, w)
+
+}
+
+// GetPetById - Find pet by ID
+func (c *PetApiController) GetPetById(w http.ResponseWriter, r *http.Request) {
+	petId, err := parseInt64Parameter(chi.URLParam(r, "petId"), true)
+	if err != nil {
+		c.errorHandler(w, r, &ParsingError{Err: err}, nil)
+		return
+	}
+
+	result, err := c.service.GetPetById(r.Context(), petId)
+	// If an error occurred, encode the error with the status code
+	if err != nil {
+		c.errorHandler(w, r, err, &result)
+		return
+	}
+	// If no error, encode the body and the result code
+	EncodeJSONResponse(result.Body, &result.Code, result.Headers, w)
+
+}
+
+// UpdatePet - Update an existing pet
+func (c *PetApiController) UpdatePet(w http.ResponseWriter, r *http.Request) {
+	pet := Pet{}
+	d := json.NewDecoder(r.Body)
+	d.DisallowUnknownFields()
+	if err := d.Decode(&pet); err != nil {
+		c.errorHandler(w, r, &ParsingError{Err: err}, nil)
+		return
+	}
+	if err := AssertPetRequired(pet); err != nil {
+		c.errorHandler(w, r, err, nil)
+		return
+	}
+	result, err := c.service.UpdatePet(r.Context(), pet)
+	// If an error occurred, encode the error with the status code
+	if err != nil {
+		c.errorHandler(w, r, err, &result)
+		return
+	}
+	// If no error, encode the body and the result code
+	EncodeJSONResponse(result.Body, &result.Code, result.Headers, w)
+
+}
+
+// UpdatePetWithForm - Updates a pet in the store with form data
+func (c *PetApiController) UpdatePetWithForm(w http.ResponseWriter, r *http.Request) {
+	if err := r.ParseForm(); err != nil {
+		c.errorHandler(w, r, &ParsingError{Err: err}, nil)
+		return
+	}
+	petId, err := parseInt64Parameter(chi.URLParam(r, "petId"), true)
+	if err != nil {
+		c.errorHandler(w, r, &ParsingError{Err: err}, nil)
+		return
+	}
+
+				name := r.FormValue("name")
+				status := r.FormValue("status")
+	result, err := c.service.UpdatePetWithForm(r.Context(), petId, name, status)
+	// If an error occurred, encode the error with the status code
+	if err != nil {
+		c.errorHandler(w, r, err, &result)
+		return
+	}
+	// If no error, encode the body and the result code
+	EncodeJSONResponse(result.Body, &result.Code, result.Headers, w)
+
+}
+
+// UploadFile - uploads an image
+func (c *PetApiController) UploadFile(w http.ResponseWriter, r *http.Request) {
+	if err := r.ParseMultipartForm(32 << 20); err != nil {
+		c.errorHandler(w, r, &ParsingError{Err: err}, nil)
+		return
+	}
+	petId, err := parseInt64Parameter(chi.URLParam(r, "petId"), true)
+	if err != nil {
+		c.errorHandler(w, r, &ParsingError{Err: err}, nil)
+		return
+	}
+
+				additionalMetadata := r.FormValue("additionalMetadata")
+	
+	file, err := ReadFormFileToTempFile(r, "file")
+	if err != nil {
+		c.errorHandler(w, r, &ParsingError{Err: err}, nil)
+		return
+	}
+			result, err := c.service.UploadFile(r.Context(), petId, additionalMetadata, file)
+	// If an error occurred, encode the error with the status code
+	if err != nil {
+		c.errorHandler(w, r, err, &result)
+		return
+	}
+	// If no error, encode the body and the result code
+	EncodeJSONResponse(result.Body, &result.Code, result.Headers, w)
+
+}

samples/server/petstore/go-server-required/go/api_pet_service.go

@@ -0,0 +1,142 @@
+/*
+ * OpenAPI Petstore
+ *
+ * This is a sample server Petstore server. For this sample, you can use the api key `special-key` to test the authorization filters.
+ *
+ * API version: 1.0.0
+ * Generated by: OpenAPI Generator (https://openapi-generator.tech)
+ */
+
+package petstoreserver
+
+import (
+	"context"
+	"net/http"
+	"errors"
+	"os"
+)
+
+// PetApiService is a service that implents the logic for the PetApiServicer
+// This service should implement the business logic for every endpoint for the PetApi API. 
+// Include any external packages or services that will be required by this service.
+type PetApiService struct {
+}
+
+// NewPetApiService creates a default api service
+func NewPetApiService() PetApiServicer {
+	return &PetApiService{}
+}
+
+// AddPet - Add a new pet to the store
+func (s *PetApiService) AddPet(ctx context.Context, pet Pet) (ImplResponse, error) {
+	// TODO - update AddPet with the required logic for this service method.
+	// Add api_pet_service.go to the .openapi-generator-ignore to avoid overwriting this service implementation when updating open api generation.
+
+	//TODO: Uncomment the next line to return response Response(200, Pet{}) or use other options such as http.Ok ...
+	//return Response(200, Pet{}), nil
+
+	//TODO: Uncomment the next line to return response Response(405, {}) or use other options such as http.Ok ...
+	//return Response(405, nil),nil
+
+	return Response(http.StatusNotImplemented, nil), errors.New("AddPet method not implemented")
+}
+
+// DeletePet - Deletes a pet
+func (s *PetApiService) DeletePet(ctx context.Context, petId int64, apiKey string) (ImplResponse, error) {
+	// TODO - update DeletePet with the required logic for this service method.
+	// Add api_pet_service.go to the .openapi-generator-ignore to avoid overwriting this service implementation when updating open api generation.
+
+	//TODO: Uncomment the next line to return response Response(400, {}) or use other options such as http.Ok ...
+	//return Response(400, nil),nil
+
+	return Response(http.StatusNotImplemented, nil), errors.New("DeletePet method not implemented")
+}
+
+// FindPetsByStatus - Finds Pets by status
+func (s *PetApiService) FindPetsByStatus(ctx context.Context, status []string) (ImplResponse, error) {
+	// TODO - update FindPetsByStatus with the required logic for this service method.
+	// Add api_pet_service.go to the .openapi-generator-ignore to avoid overwriting this service implementation when updating open api generation.
+
+	//TODO: Uncomment the next line to return response Response(200, []Pet{}) or use other options such as http.Ok ...
+	//return Response(200, []Pet{}), nil
+
+	//TODO: Uncomment the next line to return response Response(400, {}) or use other options such as http.Ok ...
+	//return Response(400, nil),nil
+
+	return Response(http.StatusNotImplemented, nil), errors.New("FindPetsByStatus method not implemented")
+}
+
+// FindPetsByTags - Finds Pets by tags
+// Deprecated
+func (s *PetApiService) FindPetsByTags(ctx context.Context, tags []string) (ImplResponse, error) {
+	// TODO - update FindPetsByTags with the required logic for this service method.
+	// Add api_pet_service.go to the .openapi-generator-ignore to avoid overwriting this service implementation when updating open api generation.
+
+	//TODO: Uncomment the next line to return response Response(200, []Pet{}) or use other options such as http.Ok ...
+	//return Response(200, []Pet{}), nil
+
+	//TODO: Uncomment the next line to return response Response(400, {}) or use other options such as http.Ok ...
+	//return Response(400, nil),nil
+
+	return Response(http.StatusNotImplemented, nil), errors.New("FindPetsByTags method not implemented")
+}
+
+// GetPetById - Find pet by ID
+func (s *PetApiService) GetPetById(ctx context.Context, petId int64) (ImplResponse, error) {
+	// TODO - update GetPetById with the required logic for this service method.
+	// Add api_pet_service.go to the .openapi-generator-ignore to avoid overwriting this service implementation when updating open api generation.
+
+	//TODO: Uncomment the next line to return response Response(200, Pet{}) or use other options such as http.Ok ...
+	//return Response(200, Pet{}), nil
+
+	//TODO: Uncomment the next line to return response Response(400, {}) or use other options such as http.Ok ...
+	//return Response(400, nil),nil
+
+	//TODO: Uncomment the next line to return response Response(404, {}) or use other options such as http.Ok ...
+	//return Response(404, nil),nil
+
+	return Response(http.StatusNotImplemented, nil), errors.New("GetPetById method not implemented")
+}
+
+// UpdatePet - Update an existing pet
+func (s *PetApiService) UpdatePet(ctx context.Context, pet Pet) (ImplResponse, error) {
+	// TODO - update UpdatePet with the required logic for this service method.
+	// Add api_pet_service.go to the .openapi-generator-ignore to avoid overwriting this service implementation when updating open api generation.
+
+	//TODO: Uncomment the next line to return response Response(200, Pet{}) or use other options such as http.Ok ...
+	//return Response(200, Pet{}), nil
+
+	//TODO: Uncomment the next line to return response Response(400, {}) or use other options such as http.Ok ...
+	//return Response(400, nil),nil
+
+	//TODO: Uncomment the next line to return response Response(404, {}) or use other options such as http.Ok ...
+	//return Response(404, nil),nil
+
+	//TODO: Uncomment the next line to return response Response(405, {}) or use other options such as http.Ok ...
+	//return Response(405, nil),nil
+
+	return Response(http.StatusNotImplemented, nil), errors.New("UpdatePet method not implemented")
+}
+
+// UpdatePetWithForm - Updates a pet in the store with form data
+func (s *PetApiService) UpdatePetWithForm(ctx context.Context, petId int64, name string, status string) (ImplResponse, error) {
+	// TODO - update UpdatePetWithForm with the required logic for this service method.
+	// Add api_pet_service.go to the .openapi-generator-ignore to avoid overwriting this service implementation when updating open api generation.
+
+	//TODO: Uncomment the next line to return response Response(405, {}) or use other options such as http.Ok ...
+	//return Response(405, nil),nil
+
+	return Response(http.StatusNotImplemented, nil), errors.New("UpdatePetWithForm method not implemented")
+}
+
+// UploadFile - uploads an image
+func (s *PetApiService) UploadFile(ctx context.Context, petId int64, additionalMetadata string, file *os.File) (ImplResponse, error) {
+	// TODO - update UploadFile with the required logic for this service method.
+	// Add api_pet_service.go to the .openapi-generator-ignore to avoid overwriting this service implementation when updating open api generation.
+
+	//TODO: Uncomment the next line to return response Response(200, ApiResponse{}) or use other options such as http.Ok ...
+	//return Response(200, ApiResponse{}), nil
+
+	return Response(http.StatusNotImplemented, nil), errors.New("UploadFile method not implemented")
+}
+

samples/server/petstore/go-server-required/go/api_store.go

@@ -0,0 +1,149 @@
+/*
+ * OpenAPI Petstore
+ *
+ * This is a sample server Petstore server. For this sample, you can use the api key `special-key` to test the authorization filters.
+ *
+ * API version: 1.0.0
+ * Generated by: OpenAPI Generator (https://openapi-generator.tech)
+ */
+
+package petstoreserver
+
+import (
+	"encoding/json"
+	"net/http"
+	"strings"
+
+	"github.com/go-chi/chi/v5"
+)
+
+// StoreApiController binds http requests to an api service and writes the service results to the http response
+type StoreApiController struct {
+	service StoreApiServicer
+	errorHandler ErrorHandler
+}
+
+// StoreApiOption for how the controller is set up.
+type StoreApiOption func(*StoreApiController)
+
+// WithStoreApiErrorHandler inject ErrorHandler into controller
+func WithStoreApiErrorHandler(h ErrorHandler) StoreApiOption {
+	return func(c *StoreApiController) {
+		c.errorHandler = h
+	}
+}
+
+// NewStoreApiController creates a default api controller
+func NewStoreApiController(s StoreApiServicer, opts ...StoreApiOption) Router {
+	controller := &StoreApiController{
+		service:      s,
+		errorHandler: DefaultErrorHandler,
+	}
+
+	for _, opt := range opts {
+		opt(controller)
+	}
+
+	return controller
+}
+
+// Routes returns all of the api route for the StoreApiController
+func (c *StoreApiController) Routes() Routes {
+	return Routes{ 
+		{
+			"DeleteOrder",
+			strings.ToUpper("Delete"),
+			"/v2/store/order/{orderId}",
+			c.DeleteOrder,
+		},
+		{
+			"GetInventory",
+			strings.ToUpper("Get"),
+			"/v2/store/inventory",
+			c.GetInventory,
+		},
+		{
+			"GetOrderById",
+			strings.ToUpper("Get"),
+			"/v2/store/order/{orderId}",
+			c.GetOrderById,
+		},
+		{
+			"PlaceOrder",
+			strings.ToUpper("Post"),
+			"/v2/store/order",
+			c.PlaceOrder,
+		},
+	}
+}
+
+// DeleteOrder - Delete purchase order by ID
+func (c *StoreApiController) DeleteOrder(w http.ResponseWriter, r *http.Request) {
+	orderId := chi.URLParam(r, "orderId")
+	
+	result, err := c.service.DeleteOrder(r.Context(), orderId)
+	// If an error occurred, encode the error with the status code
+	if err != nil {
+		c.errorHandler(w, r, err, &result)
+		return
+	}
+	// If no error, encode the body and the result code
+	EncodeJSONResponse(result.Body, &result.Code, result.Headers, w)
+
+}
+
+// GetInventory - Returns pet inventories by status
+func (c *StoreApiController) GetInventory(w http.ResponseWriter, r *http.Request) {
+	result, err := c.service.GetInventory(r.Context())
+	// If an error occurred, encode the error with the status code
+	if err != nil {
+		c.errorHandler(w, r, err, &result)
+		return
+	}
+	// If no error, encode the body and the result code
+	EncodeJSONResponse(result.Body, &result.Code, result.Headers, w)
+
+}
+
+// GetOrderById - Find purchase order by ID
+func (c *StoreApiController) GetOrderById(w http.ResponseWriter, r *http.Request) {
+	orderId, err := parseInt64Parameter(chi.URLParam(r, "orderId"), true)
+	if err != nil {
+		c.errorHandler(w, r, &ParsingError{Err: err}, nil)
+		return
+	}
+
+	result, err := c.service.GetOrderById(r.Context(), orderId)
+	// If an error occurred, encode the error with the status code
+	if err != nil {
+		c.errorHandler(w, r, err, &result)
+		return
+	}
+	// If no error, encode the body and the result code
+	EncodeJSONResponse(result.Body, &result.Code, result.Headers, w)
+
+}
+
+// PlaceOrder - Place an order for a pet
+func (c *StoreApiController) PlaceOrder(w http.ResponseWriter, r *http.Request) {
+	order := Order{}
+	d := json.NewDecoder(r.Body)
+	d.DisallowUnknownFields()
+	if err := d.Decode(&order); err != nil {
+		c.errorHandler(w, r, &ParsingError{Err: err}, nil)
+		return
+	}
+	if err := AssertOrderRequired(order); err != nil {
+		c.errorHandler(w, r, err, nil)
+		return
+	}
+	result, err := c.service.PlaceOrder(r.Context(), order)
+	// If an error occurred, encode the error with the status code
+	if err != nil {
+		c.errorHandler(w, r, err, &result)
+		return
+	}
+	// If no error, encode the body and the result code
+	EncodeJSONResponse(result.Body, &result.Code, result.Headers, w)
+
+}

samples/server/petstore/go-server-required/go/api_store_service.go

@@ -0,0 +1,84 @@
+/*
+ * OpenAPI Petstore
+ *
+ * This is a sample server Petstore server. For this sample, you can use the api key `special-key` to test the authorization filters.
+ *
+ * API version: 1.0.0
+ * Generated by: OpenAPI Generator (https://openapi-generator.tech)
+ */
+
+package petstoreserver
+
+import (
+	"context"
+	"net/http"
+	"errors"
+)
+
+// StoreApiService is a service that implents the logic for the StoreApiServicer
+// This service should implement the business logic for every endpoint for the StoreApi API. 
+// Include any external packages or services that will be required by this service.
+type StoreApiService struct {
+}
+
+// NewStoreApiService creates a default api service
+func NewStoreApiService() StoreApiServicer {
+	return &StoreApiService{}
+}
+
+// DeleteOrder - Delete purchase order by ID
+func (s *StoreApiService) DeleteOrder(ctx context.Context, orderId string) (ImplResponse, error) {
+	// TODO - update DeleteOrder with the required logic for this service method.
+	// Add api_store_service.go to the .openapi-generator-ignore to avoid overwriting this service implementation when updating open api generation.
+
+	//TODO: Uncomment the next line to return response Response(400, {}) or use other options such as http.Ok ...
+	//return Response(400, nil),nil
+
+	//TODO: Uncomment the next line to return response Response(404, {}) or use other options such as http.Ok ...
+	//return Response(404, nil),nil
+
+	return Response(http.StatusNotImplemented, nil), errors.New("DeleteOrder method not implemented")
+}
+
+// GetInventory - Returns pet inventories by status
+func (s *StoreApiService) GetInventory(ctx context.Context) (ImplResponse, error) {
+	// TODO - update GetInventory with the required logic for this service method.
+	// Add api_store_service.go to the .openapi-generator-ignore to avoid overwriting this service implementation when updating open api generation.
+
+	//TODO: Uncomment the next line to return response Response(200, map[string]int32{}) or use other options such as http.Ok ...
+	//return Response(200, map[string]int32{}), nil
+
+	return Response(http.StatusNotImplemented, nil), errors.New("GetInventory method not implemented")
+}
+
+// GetOrderById - Find purchase order by ID
+func (s *StoreApiService) GetOrderById(ctx context.Context, orderId int64) (ImplResponse, error) {
+	// TODO - update GetOrderById with the required logic for this service method.
+	// Add api_store_service.go to the .openapi-generator-ignore to avoid overwriting this service implementation when updating open api generation.
+
+	//TODO: Uncomment the next line to return response Response(200, Order{}) or use other options such as http.Ok ...
+	//return Response(200, Order{}), nil
+
+	//TODO: Uncomment the next line to return response Response(400, {}) or use other options such as http.Ok ...
+	//return Response(400, nil),nil
+
+	//TODO: Uncomment the next line to return response Response(404, {}) or use other options such as http.Ok ...
+	//return Response(404, nil),nil
+
+	return Response(http.StatusNotImplemented, nil), errors.New("GetOrderById method not implemented")
+}
+
+// PlaceOrder - Place an order for a pet
+func (s *StoreApiService) PlaceOrder(ctx context.Context, order Order) (ImplResponse, error) {
+	// TODO - update PlaceOrder with the required logic for this service method.
+	// Add api_store_service.go to the .openapi-generator-ignore to avoid overwriting this service implementation when updating open api generation.
+
+	//TODO: Uncomment the next line to return response Response(200, Order{}) or use other options such as http.Ok ...
+	//return Response(200, Order{}), nil
+
+	//TODO: Uncomment the next line to return response Response(400, {}) or use other options such as http.Ok ...
+	//return Response(400, nil),nil
+
+	return Response(http.StatusNotImplemented, nil), errors.New("PlaceOrder method not implemented")
+}
+

samples/server/petstore/go-server-required/go/api_user.go

@@ -0,0 +1,263 @@
+/*
+ * OpenAPI Petstore
+ *
+ * This is a sample server Petstore server. For this sample, you can use the api key `special-key` to test the authorization filters.
+ *
+ * API version: 1.0.0
+ * Generated by: OpenAPI Generator (https://openapi-generator.tech)
+ */
+
+package petstoreserver
+
+import (
+	"encoding/json"
+	"net/http"
+	"strings"
+
+	"github.com/go-chi/chi/v5"
+)
+
+// UserApiController binds http requests to an api service and writes the service results to the http response
+type UserApiController struct {
+	service UserApiServicer
+	errorHandler ErrorHandler
+}
+
+// UserApiOption for how the controller is set up.
+type UserApiOption func(*UserApiController)
+
+// WithUserApiErrorHandler inject ErrorHandler into controller
+func WithUserApiErrorHandler(h ErrorHandler) UserApiOption {
+	return func(c *UserApiController) {
+		c.errorHandler = h
+	}
+}
+
+// NewUserApiController creates a default api controller
+func NewUserApiController(s UserApiServicer, opts ...UserApiOption) Router {
+	controller := &UserApiController{
+		service:      s,
+		errorHandler: DefaultErrorHandler,
+	}
+
+	for _, opt := range opts {
+		opt(controller)
+	}
+
+	return controller
+}
+
+// Routes returns all of the api route for the UserApiController
+func (c *UserApiController) Routes() Routes {
+	return Routes{ 
+		{
+			"CreateUser",
+			strings.ToUpper("Post"),
+			"/v2/user",
+			c.CreateUser,
+		},
+		{
+			"CreateUsersWithArrayInput",
+			strings.ToUpper("Post"),
+			"/v2/user/createWithArray",
+			c.CreateUsersWithArrayInput,
+		},
+		{
+			"CreateUsersWithListInput",
+			strings.ToUpper("Post"),
+			"/v2/user/createWithList",
+			c.CreateUsersWithListInput,
+		},
+		{
+			"DeleteUser",
+			strings.ToUpper("Delete"),
+			"/v2/user/{username}",
+			c.DeleteUser,
+		},
+		{
+			"GetUserByName",
+			strings.ToUpper("Get"),
+			"/v2/user/{username}",
+			c.GetUserByName,
+		},
+		{
+			"LoginUser",
+			strings.ToUpper("Get"),
+			"/v2/user/login",
+			c.LoginUser,
+		},
+		{
+			"LogoutUser",
+			strings.ToUpper("Get"),
+			"/v2/user/logout",
+			c.LogoutUser,
+		},
+		{
+			"UpdateUser",
+			strings.ToUpper("Put"),
+			"/v2/user/{username}",
+			c.UpdateUser,
+		},
+	}
+}
+
+// CreateUser - Create user
+func (c *UserApiController) CreateUser(w http.ResponseWriter, r *http.Request) {
+	user := User{}
+	d := json.NewDecoder(r.Body)
+	d.DisallowUnknownFields()
+	if err := d.Decode(&user); err != nil {
+		c.errorHandler(w, r, &ParsingError{Err: err}, nil)
+		return
+	}
+	if err := AssertUserRequired(user); err != nil {
+		c.errorHandler(w, r, err, nil)
+		return
+	}
+	result, err := c.service.CreateUser(r.Context(), user)
+	// If an error occurred, encode the error with the status code
+	if err != nil {
+		c.errorHandler(w, r, err, &result)
+		return
+	}
+	// If no error, encode the body and the result code
+	EncodeJSONResponse(result.Body, &result.Code, result.Headers, w)
+
+}
+
+// CreateUsersWithArrayInput - Creates list of users with given input array
+func (c *UserApiController) CreateUsersWithArrayInput(w http.ResponseWriter, r *http.Request) {
+	user := []User{}
+	d := json.NewDecoder(r.Body)
+	d.DisallowUnknownFields()
+	if err := d.Decode(&user); err != nil {
+		c.errorHandler(w, r, &ParsingError{Err: err}, nil)
+		return
+	}
+	for _, el := range user {
+		if err := AssertUserRequired(el); err != nil {
+			c.errorHandler(w, r, err, nil)
+			return
+		}
+	}
+	result, err := c.service.CreateUsersWithArrayInput(r.Context(), user)
+	// If an error occurred, encode the error with the status code
+	if err != nil {
+		c.errorHandler(w, r, err, &result)
+		return
+	}
+	// If no error, encode the body and the result code
+	EncodeJSONResponse(result.Body, &result.Code, result.Headers, w)
+
+}
+
+// CreateUsersWithListInput - Creates list of users with given input array
+func (c *UserApiController) CreateUsersWithListInput(w http.ResponseWriter, r *http.Request) {
+	user := []User{}
+	d := json.NewDecoder(r.Body)
+	d.DisallowUnknownFields()
+	if err := d.Decode(&user); err != nil {
+		c.errorHandler(w, r, &ParsingError{Err: err}, nil)
+		return
+	}
+	for _, el := range user {
+		if err := AssertUserRequired(el); err != nil {
+			c.errorHandler(w, r, err, nil)
+			return
+		}
+	}
+	result, err := c.service.CreateUsersWithListInput(r.Context(), user)
+	// If an error occurred, encode the error with the status code
+	if err != nil {
+		c.errorHandler(w, r, err, &result)
+		return
+	}
+	// If no error, encode the body and the result code
+	EncodeJSONResponse(result.Body, &result.Code, result.Headers, w)
+
+}
+
+// DeleteUser - Delete user
+func (c *UserApiController) DeleteUser(w http.ResponseWriter, r *http.Request) {
+	username := chi.URLParam(r, "username")
+	
+	result, err := c.service.DeleteUser(r.Context(), username)
+	// If an error occurred, encode the error with the status code
+	if err != nil {
+		c.errorHandler(w, r, err, &result)
+		return
+	}
+	// If no error, encode the body and the result code
+	EncodeJSONResponse(result.Body, &result.Code, result.Headers, w)
+
+}
+
+// GetUserByName - Get user by user name
+func (c *UserApiController) GetUserByName(w http.ResponseWriter, r *http.Request) {
+	username := chi.URLParam(r, "username")
+	
+	result, err := c.service.GetUserByName(r.Context(), username)
+	// If an error occurred, encode the error with the status code
+	if err != nil {
+		c.errorHandler(w, r, err, &result)
+		return
+	}
+	// If no error, encode the body and the result code
+	EncodeJSONResponse(result.Body, &result.Code, result.Headers, w)
+
+}
+
+// LoginUser - Logs user into the system
+func (c *UserApiController) LoginUser(w http.ResponseWriter, r *http.Request) {
+	query := r.URL.Query()
+	username := query.Get("username")
+	password := query.Get("password")
+	result, err := c.service.LoginUser(r.Context(), username, password)
+	// If an error occurred, encode the error with the status code
+	if err != nil {
+		c.errorHandler(w, r, err, &result)
+		return
+	}
+	// If no error, encode the body and the result code
+	EncodeJSONResponse(result.Body, &result.Code, result.Headers, w)
+
+}
+
+// LogoutUser - Logs out current logged in user session
+func (c *UserApiController) LogoutUser(w http.ResponseWriter, r *http.Request) {
+	result, err := c.service.LogoutUser(r.Context())
+	// If an error occurred, encode the error with the status code
+	if err != nil {
+		c.errorHandler(w, r, err, &result)
+		return
+	}
+	// If no error, encode the body and the result code
+	EncodeJSONResponse(result.Body, &result.Code, result.Headers, w)
+
+}
+
+// UpdateUser - Updated user
+func (c *UserApiController) UpdateUser(w http.ResponseWriter, r *http.Request) {
+	username := chi.URLParam(r, "username")
+	
+	user := User{}
+	d := json.NewDecoder(r.Body)
+	d.DisallowUnknownFields()
+	if err := d.Decode(&user); err != nil {
+		c.errorHandler(w, r, &ParsingError{Err: err}, nil)
+		return
+	}
+	if err := AssertUserRequired(user); err != nil {
+		c.errorHandler(w, r, err, nil)
+		return
+	}
+	result, err := c.service.UpdateUser(r.Context(), username, user)
+	// If an error occurred, encode the error with the status code
+	if err != nil {
+		c.errorHandler(w, r, err, &result)
+		return
+	}
+	// If no error, encode the body and the result code
+	EncodeJSONResponse(result.Body, &result.Code, result.Headers, w)
+
+}

samples/server/petstore/go-server-required/go/api_user_service.go

@@ -0,0 +1,131 @@
+/*
+ * OpenAPI Petstore
+ *
+ * This is a sample server Petstore server. For this sample, you can use the api key `special-key` to test the authorization filters.
+ *
+ * API version: 1.0.0
+ * Generated by: OpenAPI Generator (https://openapi-generator.tech)
+ */
+
+package petstoreserver
+
+import (
+	"context"
+	"net/http"
+	"errors"
+)
+
+// UserApiService is a service that implents the logic for the UserApiServicer
+// This service should implement the business logic for every endpoint for the UserApi API. 
+// Include any external packages or services that will be required by this service.
+type UserApiService struct {
+}
+
+// NewUserApiService creates a default api service
+func NewUserApiService() UserApiServicer {
+	return &UserApiService{}
+}
+
+// CreateUser - Create user
+func (s *UserApiService) CreateUser(ctx context.Context, user User) (ImplResponse, error) {
+	// TODO - update CreateUser with the required logic for this service method.
+	// Add api_user_service.go to the .openapi-generator-ignore to avoid overwriting this service implementation when updating open api generation.
+
+	//TODO: Uncomment the next line to return response Response(0, {}) or use other options such as http.Ok ...
+	//return Response(0, nil),nil
+
+	return Response(http.StatusNotImplemented, nil), errors.New("CreateUser method not implemented")
+}
+
+// CreateUsersWithArrayInput - Creates list of users with given input array
+func (s *UserApiService) CreateUsersWithArrayInput(ctx context.Context, user []User) (ImplResponse, error) {
+	// TODO - update CreateUsersWithArrayInput with the required logic for this service method.
+	// Add api_user_service.go to the .openapi-generator-ignore to avoid overwriting this service implementation when updating open api generation.
+
+	//TODO: Uncomment the next line to return response Response(0, {}) or use other options such as http.Ok ...
+	//return Response(0, nil),nil
+
+	return Response(http.StatusNotImplemented, nil), errors.New("CreateUsersWithArrayInput method not implemented")
+}
+
+// CreateUsersWithListInput - Creates list of users with given input array
+func (s *UserApiService) CreateUsersWithListInput(ctx context.Context, user []User) (ImplResponse, error) {
+	// TODO - update CreateUsersWithListInput with the required logic for this service method.
+	// Add api_user_service.go to the .openapi-generator-ignore to avoid overwriting this service implementation when updating open api generation.
+
+	//TODO: Uncomment the next line to return response Response(0, {}) or use other options such as http.Ok ...
+	//return Response(0, nil),nil
+
+	return Response(http.StatusNotImplemented, nil), errors.New("CreateUsersWithListInput method not implemented")
+}
+
+// DeleteUser - Delete user
+func (s *UserApiService) DeleteUser(ctx context.Context, username string) (ImplResponse, error) {
+	// TODO - update DeleteUser with the required logic for this service method.
+	// Add api_user_service.go to the .openapi-generator-ignore to avoid overwriting this service implementation when updating open api generation.
+
+	//TODO: Uncomment the next line to return response Response(400, {}) or use other options such as http.Ok ...
+	//return Response(400, nil),nil
+
+	//TODO: Uncomment the next line to return response Response(404, {}) or use other options such as http.Ok ...
+	//return Response(404, nil),nil
+
+	return Response(http.StatusNotImplemented, nil), errors.New("DeleteUser method not implemented")
+}
+
+// GetUserByName - Get user by user name
+func (s *UserApiService) GetUserByName(ctx context.Context, username string) (ImplResponse, error) {
+	// TODO - update GetUserByName with the required logic for this service method.
+	// Add api_user_service.go to the .openapi-generator-ignore to avoid overwriting this service implementation when updating open api generation.
+
+	//TODO: Uncomment the next line to return response Response(200, User{}) or use other options such as http.Ok ...
+	//return Response(200, User{}), nil
+
+	//TODO: Uncomment the next line to return response Response(400, {}) or use other options such as http.Ok ...
+	//return Response(400, nil),nil
+
+	//TODO: Uncomment the next line to return response Response(404, {}) or use other options such as http.Ok ...
+	//return Response(404, nil),nil
+
+	return Response(http.StatusNotImplemented, nil), errors.New("GetUserByName method not implemented")
+}
+
+// LoginUser - Logs user into the system
+func (s *UserApiService) LoginUser(ctx context.Context, username string, password string) (ImplResponse, error) {
+	// TODO - update LoginUser with the required logic for this service method.
+	// Add api_user_service.go to the .openapi-generator-ignore to avoid overwriting this service implementation when updating open api generation.
+
+	//TODO: Uncomment the next line to return response Response(200, string{}) or use other options such as http.Ok ...
+	//return Response(200, string{}), nil
+
+	//TODO: Uncomment the next line to return response Response(400, {}) or use other options such as http.Ok ...
+	//return Response(400, nil),nil
+
+	return Response(http.StatusNotImplemented, nil), errors.New("LoginUser method not implemented")
+}
+
+// LogoutUser - Logs out current logged in user session
+func (s *UserApiService) LogoutUser(ctx context.Context) (ImplResponse, error) {
+	// TODO - update LogoutUser with the required logic for this service method.
+	// Add api_user_service.go to the .openapi-generator-ignore to avoid overwriting this service implementation when updating open api generation.
+
+	//TODO: Uncomment the next line to return response Response(0, {}) or use other options such as http.Ok ...
+	//return Response(0, nil),nil
+
+	return Response(http.StatusNotImplemented, nil), errors.New("LogoutUser method not implemented")
+}
+
+// UpdateUser - Updated user
+func (s *UserApiService) UpdateUser(ctx context.Context, username string, user User) (ImplResponse, error) {
+	// TODO - update UpdateUser with the required logic for this service method.
+	// Add api_user_service.go to the .openapi-generator-ignore to avoid overwriting this service implementation when updating open api generation.
+
+	//TODO: Uncomment the next line to return response Response(400, {}) or use other options such as http.Ok ...
+	//return Response(400, nil),nil
+
+	//TODO: Uncomment the next line to return response Response(404, {}) or use other options such as http.Ok ...
+	//return Response(404, nil),nil
+
+	return Response(http.StatusNotImplemented, nil), errors.New("UpdateUser method not implemented")
+}
+

samples/server/petstore/go-server-required/go/error.go

@@ -0,0 +1,62 @@
+/*
+ * OpenAPI Petstore
+ *
+ * This is a sample server Petstore server. For this sample, you can use the api key `special-key` to test the authorization filters.
+ *
+ * API version: 1.0.0
+ * Generated by: OpenAPI Generator (https://openapi-generator.tech)
+ */
+
+package petstoreserver
+
+import (
+	"errors"
+	"fmt"
+	"net/http"
+)
+
+var (
+	// ErrTypeAssertionError is thrown when type an interface does not match the asserted type
+	ErrTypeAssertionError = errors.New("unable to assert type")
+)
+
+// ParsingError indicates that an error has occurred when parsing request parameters
+type ParsingError struct {
+	Err error
+}
+
+func (e *ParsingError) Unwrap() error {
+	return e.Err
+}
+
+func (e *ParsingError) Error() string {
+	return e.Err.Error()
+}
+
+// RequiredError indicates that an error has occurred when parsing request parameters
+type RequiredError struct {
+	Field string
+}
+
+func (e *RequiredError) Error() string {
+	return fmt.Sprintf("required field '%s' is zero value.", e.Field)
+}
+
+// ErrorHandler defines the required method for handling error. You may implement it and inject this into a controller if
+// you would like errors to be handled differently from the DefaultErrorHandler
+type ErrorHandler func(w http.ResponseWriter, r *http.Request, err error, result *ImplResponse)
+
+// DefaultErrorHandler defines the default logic on how to handle errors from the controller. Any errors from parsing
+// request params will return a StatusBadRequest. Otherwise, the error code originating from the servicer will be used.
+func DefaultErrorHandler(w http.ResponseWriter, r *http.Request, err error, result *ImplResponse) {
+	if _, ok := err.(*ParsingError); ok {
+		// Handle parsing errors
+		EncodeJSONResponse(err.Error(), func(i int) *int { return &i }(http.StatusBadRequest), map[string][]string{}, w)
+	} else if _, ok := err.(*RequiredError); ok {
+		// Handle missing required errors
+		EncodeJSONResponse(err.Error(), func(i int) *int { return &i }(http.StatusUnprocessableEntity), map[string][]string{}, w)
+	} else {
+		// Handle all other errors
+		EncodeJSONResponse(err.Error(), &result.Code, result.Headers, w)
+	}
+}

samples/server/petstore/go-server-required/go/helpers.go

@@ -0,0 +1,64 @@
+/*
+ * OpenAPI Petstore
+ *
+ * This is a sample server Petstore server. For this sample, you can use the api key `special-key` to test the authorization filters.
+ *
+ * API version: 1.0.0
+ * Generated by: OpenAPI Generator (https://openapi-generator.tech)
+ */
+
+package petstoreserver
+
+import (
+	"reflect"
+)
+
+// Response return a ImplResponse struct filled
+func Response(code int, body interface{}) ImplResponse {
+	return ImplResponse {
+		Code: code,
+		Headers: nil,
+		Body: body,
+	}
+}
+
+// ResponseWithHeaders return a ImplResponse struct filled, including headers
+func ResponseWithHeaders(code int, headers map[string][]string, body interface{}) ImplResponse {
+	return ImplResponse {
+		Code: code,
+		Headers: headers,
+		Body: body,
+	}
+}
+
+// IsZeroValue checks if the val is the zero-ed value.
+func IsZeroValue(val interface{}) bool {
+	return val == nil || reflect.DeepEqual(val, reflect.Zero(reflect.TypeOf(val)).Interface())
+}
+
+// AssertInterfaceRequired recursively checks each struct in a slice against the callback.
+// This method traverse nested slices in a preorder fashion.
+func AssertRecurseInterfaceRequired(obj interface{}, callback func(interface{}) error) error {
+	return AssertRecurseValueRequired(reflect.ValueOf(obj), callback)
+}
+
+// AssertNestedValueRequired checks each struct in the nested slice against the callback.
+// This method traverse nested slices in a preorder fashion.
+func AssertRecurseValueRequired(value reflect.Value, callback func(interface{}) error) error {
+	switch value.Kind() {
+	// If it is a struct we check using callback
+	case reflect.Struct:
+		if err := callback(value.Interface()); err != nil {
+			return err
+		}
+
+	// If it is a slice we continue recursion
+	case reflect.Slice:
+		for i := 0; i < value.Len(); i += 1 {
+			if err := AssertRecurseValueRequired(value.Index(i), callback); err != nil {
+				return err
+			}
+		}
+	}
+	return nil
+}

samples/server/petstore/go-server-required/go/impl.go

@@ -0,0 +1,17 @@
+/*
+ * OpenAPI Petstore
+ *
+ * This is a sample server Petstore server. For this sample, you can use the api key `special-key` to test the authorization filters.
+ *
+ * API version: 1.0.0
+ * Generated by: OpenAPI Generator (https://openapi-generator.tech)
+ */
+
+package petstoreserver
+
+//Implementation response defines an error code with the associated body
+type ImplResponse struct {
+	Code int
+	Headers map[string][]string
+	Body interface{}
+}

samples/server/petstore/go-server-required/go/logger.go

@@ -0,0 +1,32 @@
+/*
+ * OpenAPI Petstore
+ *
+ * This is a sample server Petstore server. For this sample, you can use the api key `special-key` to test the authorization filters.
+ *
+ * API version: 1.0.0
+ * Generated by: OpenAPI Generator (https://openapi-generator.tech)
+ */
+
+package petstoreserver
+
+import (
+	"log"
+	"net/http"
+	"time"
+)
+
+func Logger(inner http.Handler, name string) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		start := time.Now()
+
+		inner.ServeHTTP(w, r)
+
+		log.Printf(
+			"%s %s %s %s",
+			r.Method,
+			r.RequestURI,
+			name,
+			time.Since(start),
+		)
+	})
+}

samples/server/petstore/go-server-required/go/model_api_response.go

@@ -0,0 +1,37 @@
+/*
+ * OpenAPI Petstore
+ *
+ * This is a sample server Petstore server. For this sample, you can use the api key `special-key` to test the authorization filters.
+ *
+ * API version: 1.0.0
+ * Generated by: OpenAPI Generator (https://openapi-generator.tech)
+ */
+
+package petstoreserver
+
+// ApiResponse - Describes the result of uploading an image resource
+type ApiResponse struct {
+
+	Code int32 `json:"code,omitempty"`
+
+	Type string `json:"type,omitempty"`
+
+	Message string `json:"message,omitempty"`
+}
+
+// AssertApiResponseRequired checks if the required fields are not zero-ed
+func AssertApiResponseRequired(obj ApiResponse) error {
+	return nil
+}
+
+// AssertRecurseApiResponseRequired recursively checks if required fields are not zero-ed in a nested slice.
+// Accepts only nested slice of ApiResponse (e.g. [][]ApiResponse), otherwise ErrTypeAssertionError is thrown.
+func AssertRecurseApiResponseRequired(objSlice interface{}) error {
+	return AssertRecurseInterfaceRequired(objSlice, func(obj interface{}) error {
+		aApiResponse, ok := obj.(ApiResponse)
+		if !ok {
+			return ErrTypeAssertionError
+		}
+		return AssertApiResponseRequired(aApiResponse)
+	})
+}

samples/server/petstore/go-server-required/go/model_category.go

@@ -0,0 +1,35 @@
+/*
+ * OpenAPI Petstore
+ *
+ * This is a sample server Petstore server. For this sample, you can use the api key `special-key` to test the authorization filters.
+ *
+ * API version: 1.0.0
+ * Generated by: OpenAPI Generator (https://openapi-generator.tech)
+ */
+
+package petstoreserver
+
+// Category - A category for a pet
+type Category struct {
+
+	Id int64 `json:"id,omitempty"`
+
+	Name string `json:"name,omitempty"`
+}
+
+// AssertCategoryRequired checks if the required fields are not zero-ed
+func AssertCategoryRequired(obj Category) error {
+	return nil
+}
+
+// AssertRecurseCategoryRequired recursively checks if required fields are not zero-ed in a nested slice.
+// Accepts only nested slice of Category (e.g. [][]Category), otherwise ErrTypeAssertionError is thrown.
+func AssertRecurseCategoryRequired(objSlice interface{}) error {
+	return AssertRecurseInterfaceRequired(objSlice, func(obj interface{}) error {
+		aCategory, ok := obj.(Category)
+		if !ok {
+			return ErrTypeAssertionError
+		}
+		return AssertCategoryRequired(aCategory)
+	})
+}

samples/server/petstore/go-server-required/go/model_order.go

@@ -0,0 +1,64 @@
+/*
+ * OpenAPI Petstore
+ *
+ * This is a sample server Petstore server. For this sample, you can use the api key `special-key` to test the authorization filters.
+ *
+ * API version: 1.0.0
+ * Generated by: OpenAPI Generator (https://openapi-generator.tech)
+ */
+
+package petstoreserver
+
+import (
+	"time"
+)
+
+// Order - An order for a pets from the pet store
+type Order struct {
+	SpecialInfo
+
+	Id int64 `json:"id,omitempty"`
+
+	// Order Status
+	Status string `json:"status,omitempty"`
+
+	Complete bool `json:"complete,omitempty"`
+
+	Comment *string `json:"comment"`
+
+	PetId int64 `json:"petId,omitempty"`
+
+	Quantity int32 `json:"quantity,omitempty"`
+
+	ShipDate time.Time `json:"shipDate,omitempty"`
+}
+
+// AssertOrderRequired checks if the required fields are not zero-ed
+func AssertOrderRequired(obj Order) error {
+	elements := map[string]interface{}{
+		"comment": obj.Comment,
+	}
+	for name, el := range elements {
+		if isZero := IsZeroValue(el); isZero {
+			return &RequiredError{Field: name}
+		}
+	}
+
+	if err := AssertSpecialInfoRequired(obj.SpecialInfo); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+// AssertRecurseOrderRequired recursively checks if required fields are not zero-ed in a nested slice.
+// Accepts only nested slice of Order (e.g. [][]Order), otherwise ErrTypeAssertionError is thrown.
+func AssertRecurseOrderRequired(objSlice interface{}) error {
+	return AssertRecurseInterfaceRequired(objSlice, func(obj interface{}) error {
+		aOrder, ok := obj.(Order)
+		if !ok {
+			return ErrTypeAssertionError
+		}
+		return AssertOrderRequired(aOrder)
+	})
+}

samples/server/petstore/go-server-required/go/model_order_info.go

@@ -0,0 +1,41 @@
+/*
+ * OpenAPI Petstore
+ *
+ * This is a sample server Petstore server. For this sample, you can use the api key `special-key` to test the authorization filters.
+ *
+ * API version: 1.0.0
+ * Generated by: OpenAPI Generator (https://openapi-generator.tech)
+ */
+
+package petstoreserver
+
+import (
+	"time"
+)
+
+// OrderInfo - An order info for a pets from the pet store
+type OrderInfo struct {
+
+	PetId int64 `json:"petId,omitempty"`
+
+	Quantity int32 `json:"quantity,omitempty"`
+
+	ShipDate time.Time `json:"shipDate,omitempty"`
+}
+
+// AssertOrderInfoRequired checks if the required fields are not zero-ed
+func AssertOrderInfoRequired(obj OrderInfo) error {
+	return nil
+}
+
+// AssertRecurseOrderInfoRequired recursively checks if required fields are not zero-ed in a nested slice.
+// Accepts only nested slice of OrderInfo (e.g. [][]OrderInfo), otherwise ErrTypeAssertionError is thrown.
+func AssertRecurseOrderInfoRequired(objSlice interface{}) error {
+	return AssertRecurseInterfaceRequired(objSlice, func(obj interface{}) error {
+		aOrderInfo, ok := obj.(OrderInfo)
+		if !ok {
+			return ErrTypeAssertionError
+		}
+		return AssertOrderInfoRequired(aOrderInfo)
+	})
+}

samples/server/petstore/go-server-required/go/model_pet.go

@@ -0,0 +1,66 @@
+/*
+ * OpenAPI Petstore
+ *
+ * This is a sample server Petstore server. For this sample, you can use the api key `special-key` to test the authorization filters.
+ *
+ * API version: 1.0.0
+ * Generated by: OpenAPI Generator (https://openapi-generator.tech)
+ */
+
+package petstoreserver
+
+// Pet - A pet for sale in the pet store
+type Pet struct {
+
+	Id int64 `json:"id,omitempty"`
+
+	Category *Category `json:"category,omitempty"`
+
+	Name string `json:"name"`
+
+	PhotoUrls *[]string `json:"photoUrls"`
+
+	Tags *[]Tag `json:"tags,omitempty"`
+
+	// pet status in the store
+	Status string `json:"status,omitempty"`
+}
+
+// AssertPetRequired checks if the required fields are not zero-ed
+func AssertPetRequired(obj Pet) error {
+	elements := map[string]interface{}{
+		"name": obj.Name,
+		"photoUrls": obj.PhotoUrls,
+	}
+	for name, el := range elements {
+		if isZero := IsZeroValue(el); isZero {
+			return &RequiredError{Field: name}
+		}
+	}
+
+	if obj.Category != nil {
+		if err := AssertCategoryRequired(*obj.Category); err != nil {
+			return err
+		}
+	}
+	if obj.Tags != nil {
+		for _, el := range *obj.Tags {
+			if err := AssertTagRequired(el); err != nil {
+				return err
+			}
+		}
+	}
+	return nil
+}
+
+// AssertRecursePetRequired recursively checks if required fields are not zero-ed in a nested slice.
+// Accepts only nested slice of Pet (e.g. [][]Pet), otherwise ErrTypeAssertionError is thrown.
+func AssertRecursePetRequired(objSlice interface{}) error {
+	return AssertRecurseInterfaceRequired(objSlice, func(obj interface{}) error {
+		aPet, ok := obj.(Pet)
+		if !ok {
+			return ErrTypeAssertionError
+		}
+		return AssertPetRequired(aPet)
+	})
+}

samples/server/petstore/go-server-required/go/model_special_info.go

@@ -0,0 +1,35 @@
+/*
+ * OpenAPI Petstore
+ *
+ * This is a sample server Petstore server. For this sample, you can use the api key `special-key` to test the authorization filters.
+ *
+ * API version: 1.0.0
+ * Generated by: OpenAPI Generator (https://openapi-generator.tech)
+ */
+
+package petstoreserver
+
+// SpecialInfo - An order info for a pets from the pet store
+type SpecialInfo struct {
+
+	Promotion bool `json:"promotion,omitempty"`
+
+	Type string `json:"type,omitempty"`
+}
+
+// AssertSpecialInfoRequired checks if the required fields are not zero-ed
+func AssertSpecialInfoRequired(obj SpecialInfo) error {
+	return nil
+}
+
+// AssertRecurseSpecialInfoRequired recursively checks if required fields are not zero-ed in a nested slice.
+// Accepts only nested slice of SpecialInfo (e.g. [][]SpecialInfo), otherwise ErrTypeAssertionError is thrown.
+func AssertRecurseSpecialInfoRequired(objSlice interface{}) error {
+	return AssertRecurseInterfaceRequired(objSlice, func(obj interface{}) error {
+		aSpecialInfo, ok := obj.(SpecialInfo)
+		if !ok {
+			return ErrTypeAssertionError
+		}
+		return AssertSpecialInfoRequired(aSpecialInfo)
+	})
+}

samples/server/petstore/go-server-required/go/model_tag.go

@@ -0,0 +1,35 @@
+/*
+ * OpenAPI Petstore
+ *
+ * This is a sample server Petstore server. For this sample, you can use the api key `special-key` to test the authorization filters.
+ *
+ * API version: 1.0.0
+ * Generated by: OpenAPI Generator (https://openapi-generator.tech)
+ */
+
+package petstoreserver
+
+// Tag - A tag for a pet
+type Tag struct {
+
+	Id int64 `json:"id,omitempty"`
+
+	Name string `json:"name,omitempty"`
+}
+
+// AssertTagRequired checks if the required fields are not zero-ed
+func AssertTagRequired(obj Tag) error {
+	return nil
+}
+
+// AssertRecurseTagRequired recursively checks if required fields are not zero-ed in a nested slice.
+// Accepts only nested slice of Tag (e.g. [][]Tag), otherwise ErrTypeAssertionError is thrown.
+func AssertRecurseTagRequired(objSlice interface{}) error {
+	return AssertRecurseInterfaceRequired(objSlice, func(obj interface{}) error {
+		aTag, ok := obj.(Tag)
+		if !ok {
+			return ErrTypeAssertionError
+		}
+		return AssertTagRequired(aTag)
+	})
+}

samples/server/petstore/go-server-required/go/model_user.go

@@ -0,0 +1,68 @@
+/*
+ * OpenAPI Petstore
+ *
+ * This is a sample server Petstore server. For this sample, you can use the api key `special-key` to test the authorization filters.
+ *
+ * API version: 1.0.0
+ * Generated by: OpenAPI Generator (https://openapi-generator.tech)
+ */
+
+package petstoreserver
+
+// User - A User who is purchasing from the pet store
+type User struct {
+
+	Id int64 `json:"id,omitempty"`
+
+	Username string `json:"username,omitempty"`
+
+	FirstName string `json:"firstName,omitempty"`
+
+	LastName string `json:"lastName,omitempty"`
+
+	Email string `json:"email,omitempty"`
+
+	Password string `json:"password,omitempty"`
+
+	Phone *string `json:"phone,omitempty"`
+
+	// User Status
+	UserStatus int32 `json:"userStatus,omitempty"`
+
+	// An array 1-deep.
+	DeepSliceModel *[][][]Tag `json:"deepSliceModel"`
+
+	// An array 1-deep.
+	DeepSliceMap [][]map[string]interface{} `json:"deepSliceMap,omitempty"`
+}
+
+// AssertUserRequired checks if the required fields are not zero-ed
+func AssertUserRequired(obj User) error {
+	elements := map[string]interface{}{
+		"deepSliceModel": obj.DeepSliceModel,
+	}
+	for name, el := range elements {
+		if isZero := IsZeroValue(el); isZero {
+			return &RequiredError{Field: name}
+		}
+	}
+
+	if obj.DeepSliceModel != nil {
+		if err := AssertRecurseTagRequired(*obj.DeepSliceModel); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+// AssertRecurseUserRequired recursively checks if required fields are not zero-ed in a nested slice.
+// Accepts only nested slice of User (e.g. [][]User), otherwise ErrTypeAssertionError is thrown.
+func AssertRecurseUserRequired(objSlice interface{}) error {
+	return AssertRecurseInterfaceRequired(objSlice, func(obj interface{}) error {
+		aUser, ok := obj.(User)
+		if !ok {
+			return ErrTypeAssertionError
+		}
+		return AssertUserRequired(aUser)
+	})
+}

samples/server/petstore/go-server-required/go/routers.go

@@ -0,0 +1,221 @@
+/*
+ * OpenAPI Petstore
+ *
+ * This is a sample server Petstore server. For this sample, you can use the api key `special-key` to test the authorization filters.
+ *
+ * API version: 1.0.0
+ * Generated by: OpenAPI Generator (https://openapi-generator.tech)
+ */
+
+package petstoreserver
+
+import (
+	"encoding/json"
+	"errors"
+	"github.com/go-chi/chi/v5"
+	"github.com/go-chi/chi/v5/middleware"
+	"io/ioutil"
+	"mime/multipart"
+	"net/http"
+	"os"
+	"strconv"
+	"strings"
+)
+
+// A Route defines the parameters for an api endpoint
+type Route struct {
+	Name		string
+	Method	  string
+	Pattern	 string
+	HandlerFunc http.HandlerFunc
+}
+
+// Routes are a collection of defined api endpoints
+type Routes []Route
+
+// Router defines the required methods for retrieving api routes
+type Router interface {
+	Routes() Routes
+}
+
+const errMsgRequiredMissing = "required parameter is missing"
+
+// NewRouter creates a new router for any number of api routers
+func NewRouter(routers ...Router) chi.Router {
+	router := chi.NewRouter()
+	router.Use(middleware.Logger)
+	for _, api := range routers {
+		for _, route := range api.Routes() {
+			var handler http.Handler
+			handler = route.HandlerFunc
+			router.Method(route.Method, route.Pattern, handler)
+		}
+	}
+
+	return router
+}
+
+// EncodeJSONResponse uses the json encoder to write an interface to the http response with an optional status code
+func EncodeJSONResponse(i interface{}, status *int, headers map[string][]string, w http.ResponseWriter) error {
+	wHeader := w.Header()
+	if headers != nil {
+		for key, values := range headers {
+			for _, value := range values {
+				wHeader.Add(key, value)
+			}
+		}
+	}
+	wHeader.Set("Content-Type", "application/json; charset=UTF-8")
+	if status != nil {
+		w.WriteHeader(*status)
+	} else {
+		w.WriteHeader(http.StatusOK)
+	}
+
+	return json.NewEncoder(w).Encode(i)
+}
+
+// ReadFormFileToTempFile reads file data from a request form and writes it to a temporary file
+func ReadFormFileToTempFile(r *http.Request, key string) (*os.File, error) {
+	_, fileHeader, err := r.FormFile(key)
+	if err != nil {
+		return nil, err
+	}
+
+	return readFileHeaderToTempFile(fileHeader)
+}
+
+// ReadFormFilesToTempFiles reads files array data from a request form and writes it to a temporary files
+func ReadFormFilesToTempFiles(r *http.Request, key string) ([]*os.File, error) {
+	if err := r.ParseMultipartForm(32 << 20); err != nil {
+		return nil, err
+	}
+
+	files := make([]*os.File, 0, len(r.MultipartForm.File[key]))
+
+	for _, fileHeader := range r.MultipartForm.File[key] {
+		file, err := readFileHeaderToTempFile(fileHeader)
+		if err != nil {
+			return nil, err
+		}
+
+		files = append(files, file)
+	}
+
+	return files, nil
+}
+
+// readFileHeaderToTempFile reads multipart.FileHeader and writes it to a temporary file
+func readFileHeaderToTempFile(fileHeader *multipart.FileHeader) (*os.File, error) {
+	formFile, err := fileHeader.Open()
+	if err != nil {
+		return nil, err
+	}
+
+	defer formFile.Close()
+
+	fileBytes, err := ioutil.ReadAll(formFile)
+	if err != nil {
+		return nil, err
+	}
+
+	file, err := ioutil.TempFile("", fileHeader.Filename)
+	if err != nil {
+		return nil, err
+	}
+
+	defer file.Close()
+
+	file.Write(fileBytes)
+
+	return file, nil
+}
+
+// parseInt64Parameter parses a string parameter to an int64.
+func parseInt64Parameter(param string, required bool) (int64, error) {
+	if param == "" {
+		if required {
+			return 0, errors.New(errMsgRequiredMissing)
+		}
+
+		return 0, nil
+	}
+
+	return strconv.ParseInt(param, 10, 64)
+}
+
+// parseInt32Parameter parses a string parameter to an int32.
+func parseInt32Parameter(param string, required bool) (int32, error) {
+	if param == "" {
+		if required {
+			return 0, errors.New(errMsgRequiredMissing)
+		}
+
+		return 0, nil
+	}
+
+	val, err := strconv.ParseInt(param, 10, 32)
+	if err != nil {
+		return -1, err
+	}
+
+	return int32(val), nil
+}
+
+// parseBoolParameter parses a string parameter to a bool
+func parseBoolParameter(param string) (bool, error) {
+	val, err := strconv.ParseBool(param)
+	if err != nil {
+		return false, err
+	}
+
+	return bool(val), nil
+}
+
+// parseInt64ArrayParameter parses a string parameter containing array of values to []int64.
+func parseInt64ArrayParameter(param, delim string, required bool) ([]int64, error) {
+	if param == "" {
+		if required {
+			return nil, errors.New(errMsgRequiredMissing)
+		}
+
+		return nil, nil
+	}
+
+	str := strings.Split(param, delim)
+	ints := make([]int64, len(str))
+
+	for i, s := range str {
+		if v, err := strconv.ParseInt(s, 10, 64); err != nil {
+			return nil, err
+		} else {
+			ints[i] = v
+		}
+	}
+
+	return ints, nil
+}
+
+// parseInt32ArrayParameter parses a string parameter containing array of values to []int32.
+func parseInt32ArrayParameter(param, delim string, required bool) ([]int32, error) {
+	if param == "" {
+		if required {
+			return nil, errors.New(errMsgRequiredMissing)
+		}
+
+		return nil, nil
+	}
+
+	str := strings.Split(param, delim)
+	ints := make([]int32, len(str))
+
+	for i, s := range str {
+		if v, err := strconv.ParseInt(s, 10, 32); err != nil {
+			return nil, err
+		} else {
+			ints[i] = int32(v)
+		}
+	}
+
+	return ints, nil
+}

samples/server/petstore/go-server-required/main.go

@@ -0,0 +1,34 @@
+/*
+ * OpenAPI Petstore
+ *
+ * This is a sample server Petstore server. For this sample, you can use the api key `special-key` to test the authorization filters.
+ *
+ * API version: 1.0.0
+ * Generated by: OpenAPI Generator (https://openapi-generator.tech)
+ */
+
+package main
+
+import (
+	"log"
+	"net/http"
+
+	petstoreserver "github.com/GIT_USER_ID/GIT_REPO_ID/go"
+)
+
+func main() {
+	log.Printf("Server started")
+
+	PetApiService := petstoreserver.NewPetApiService()
+	PetApiController := petstoreserver.NewPetApiController(PetApiService)
+
+	StoreApiService := petstoreserver.NewStoreApiService()
+	StoreApiController := petstoreserver.NewStoreApiController(StoreApiService)
+
+	UserApiService := petstoreserver.NewUserApiService()
+	UserApiController := petstoreserver.NewUserApiController(UserApiService)
+
+	router := petstoreserver.NewRouter(PetApiController, StoreApiController, UserApiController)
+
+	log.Fatal(http.ListenAndServe(":8080", router))
+}