[kotlin] Support nested enums in models (#5769)

* [kotlin] Add model enum support

Model variables marked isEnum=true are nested class enums. Top-level
enums will not be isEnum=true, but rather have a datatype specific to
the enum's type.

* [kotlin] Regenerate client sample

modules/swagger-codegen/src/main/resources/kotlin-client/data_class.mustache

@@ -0,0 +1,22 @@
+/**
+ * {{{description}}}
+{{#vars}}
+ * @param {{name}} {{{description}}}
+{{/vars}}
+ */
+data class {{classname}} (
+{{#requiredVars}}
+{{>data_class_req_var}}{{^-last}},
+{{/-last}}{{/requiredVars}}{{#hasRequired}},
+{{/hasRequired}}{{#optionalVars}}{{>data_class_opt_var}}{{^-last}},
+{{/-last}}{{/optionalVars}}
+) {
+{{#hasEnums}}{{#vars}}{{#isEnum}}
+    enum class {{nameInCamelCase}}(val value: {{datatype}}) {
+    {{#_enum}}
+        {{{this}}}({{#isString}}"{{/isString}}{{{this}}}{{#isString}}"{{/isString}}){{^-last}},{{/-last}}{{#-last}};{{/-last}}
+    {{/_enum}}
+    }
+
+{{/isEnum}}{{/vars}}{{/hasEnums}}
+}

modules/swagger-codegen/src/main/resources/kotlin-client/data_class_opt_var.mustache

@@ -0,0 +1,4 @@
+{{#description}}
+    /* {{{description}}} */
+{{/description}}
+    val {{{name}}}: {{#isEnum}}{{classname}}.{{nameInCamelCase}}{{/isEnum}}{{^isEnum}}{{{datatype}}}{{/isEnum}}? = {{#defaultvalue}}{{defaultvalue}}{{/defaultvalue}}{{^defaultvalue}}null{{/defaultvalue}}

modules/swagger-codegen/src/main/resources/kotlin-client/data_class_req_var.mustache

@@ -0,0 +1,4 @@
+{{#description}}
+    /* {{{description}}} */
+{{/description}}
+    val {{{name}}}: {{#isEnum}}{{classname}}.{{nameInCamelCase}}{{/isEnum}}{{^isEnum}}{{{datatype}}}{{/isEnum}}

modules/swagger-codegen/src/main/resources/kotlin-client/enum_class.mustache

@@ -0,0 +1,9 @@
+/**
+* {{{description}}}
+* Values: {{#allowableValues}}{{#enumVars}}{{name}}{{^-last}},{{/-last}}{{/enumVars}}{{/allowableValues}}
+*/
+enum class {{classname}}(val value: {{dataType}}){
+{{#allowableValues}}{{#enumVars}}
+    {{name}}({{#isString}}"{{/isString}}{{{value}}}{{#isString}}"{{/isString}}){{^-last}},{{/-last}}{{#-last}};{{/-last}}
+{{/enumVars}}{{/allowableValues}}
+)

modules/swagger-codegen/src/main/resources/kotlin-client/model.mustache

@@ -6,19 +6,6 @@ package {{modelPackage}}
 
 {{#models}}
 {{#model}}
-/**
-* {{{description}}}
-{{#vars}}
-* @param {{name}} {{{description}}}
-{{/vars}}
-*/
-data class {{classname}} (
-  {{#vars}}
-  {{#description}}
-  /* {{{description}}} */
-  {{/description}}
-  val {{{name}}}: {{{datatype}}}{{^required}}?{{/required}}{{#hasMore}},{{/hasMore}}
-  {{/vars}}
-)
+{{#isEnum}}{{>enum_class}}{{/isEnum}}{{^isEnum}}{{>data_class}}{{/isEnum}}
 {{/model}}
 {{/models}}

samples/client/petstore/kotlin/src/main/kotlin/io/swagger/client/models/ApiResponse.kt

@@ -19,7 +19,9 @@ package io.swagger.client.models
  * @param message 
  */
 data class ApiResponse (
-  val code: kotlin.Int?,
-  val type: kotlin.String?,
-  val message: kotlin.String?
-)
+    val code: kotlin.Int? = null,
+    val type: kotlin.String? = null,
+    val message: kotlin.String? = null
+) {
+
+}

samples/client/petstore/kotlin/src/main/kotlin/io/swagger/client/models/Category.kt

@@ -18,6 +18,8 @@ package io.swagger.client.models
  * @param name 
  */
 data class Category (
-  val id: kotlin.Long?,
-  val name: kotlin.String?
-)
+    val id: kotlin.Long? = null,
+    val name: kotlin.String? = null
+) {
+
+}

samples/client/petstore/kotlin/src/main/kotlin/io/swagger/client/models/Order.kt

@@ -22,11 +22,20 @@ package io.swagger.client.models
  * @param complete 
  */
 data class Order (
-  val id: kotlin.Long?,
-  val petId: kotlin.Long?,
-  val quantity: kotlin.Int?,
-  val shipDate: java.time.LocalDateTime?,
+    val id: kotlin.Long? = null,
+    val petId: kotlin.Long? = null,
+    val quantity: kotlin.Int? = null,
+    val shipDate: java.time.LocalDateTime? = null,
     /* Order Status */
-  val status: kotlin.String?,
-  val complete: kotlin.Boolean?
-)
+    val status: Order.Status? = null,
+    val complete: kotlin.Boolean? = null
+) {
+
+    enum class Status(val value: kotlin.String) {
+        placed("placed"),
+        approved("approved"),
+        delivered("delivered");
+    }
+
+
+}

samples/client/petstore/kotlin/src/main/kotlin/io/swagger/client/models/Pet.kt

@@ -24,11 +24,20 @@ import io.swagger.client.models.Tag
  * @param status pet status in the store
  */
 data class Pet (
-  val id: kotlin.Long?,
-  val category: Category?,
     val name: kotlin.String,
     val photoUrls: kotlin.collections.List<kotlin.String>,
-  val tags: kotlin.collections.List<Tag>?,
+    val id: kotlin.Long? = null,
+    val category: Category? = null,
+    val tags: kotlin.collections.List<Tag>? = null,
     /* pet status in the store */
-  val status: kotlin.String?
-)
+    val status: Pet.Status? = null
+) {
+
+    enum class Status(val value: kotlin.String) {
+        available("available"),
+        pending("pending"),
+        sold("sold");
+    }
+
+
+}

samples/client/petstore/kotlin/src/main/kotlin/io/swagger/client/models/Tag.kt

@@ -18,6 +18,8 @@ package io.swagger.client.models
  * @param name 
  */
 data class Tag (
-  val id: kotlin.Long?,
-  val name: kotlin.String?
-)
+    val id: kotlin.Long? = null,
+    val name: kotlin.String? = null
+) {
+
+}

samples/client/petstore/kotlin/src/main/kotlin/io/swagger/client/models/User.kt

@@ -24,13 +24,15 @@ package io.swagger.client.models
  * @param userStatus User Status
  */
 data class User (
-  val id: kotlin.Long?,
-  val username: kotlin.String?,
-  val firstName: kotlin.String?,
-  val lastName: kotlin.String?,
-  val email: kotlin.String?,
-  val password: kotlin.String?,
-  val phone: kotlin.String?,
+    val id: kotlin.Long? = null,
+    val username: kotlin.String? = null,
+    val firstName: kotlin.String? = null,
+    val lastName: kotlin.String? = null,
+    val email: kotlin.String? = null,
+    val password: kotlin.String? = null,
+    val phone: kotlin.String? = null,
     /* User Status */
-  val userStatus: kotlin.Int?
-)
+    val userStatus: kotlin.Int? = null
+) {
+
+}

samples/client/petstore/kotlin/src/test/kotlin/io/swagger/client/functional/EvaluateTest.kt

@@ -9,7 +9,7 @@ class EvaluateTest : ShouldSpec() {
     init {
         should("query against pet statuses") {
             val api = PetApi()
-            val results = api.findPetsByStatus(listOf("available", "pending"))
+            val results = api.findPetsByStatus(listOf("sold"))
 
             results.size should beGreaterThan(1)
         }