[go-server] add field name in parsing error messages (#18533)

Currently when a parsing rule of a field is not respected (eg: min/max
value, required, ...), the api only returns an  error message without
providing the field name to help the user to fix the request. This commit
add the field name to the error message to help the user of the API.

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

@@ -161,7 +161,7 @@ func (c *PetAPIController) DeletePet(w http.ResponseWriter, r *http.Request) {
 		WithRequire[int64](parseInt64),
 	)
 	if err != nil {
-		c.errorHandler(w, r, &ParsingError{Err: err}, nil)
+		c.errorHandler(w, r, &ParsingError{Param: "petId", Err: err}, nil)
 		return
 	}
 	apiKeyParam := r.Header.Get("api_key")
@@ -185,7 +185,7 @@ func (c *PetAPIController) FilterPetsByCategory(w http.ResponseWriter, r *http.R
 	}
 	genderParam, err := NewGenderFromValue(params["gender"])
 	if err != nil {
-		c.errorHandler(w, r, &ParsingError{Err: err}, nil)
+		c.errorHandler(w, r, &ParsingError{Param: "gender", Err: err}, nil)
 		return
 	}
 	var speciesParam Species
@@ -204,7 +204,7 @@ func (c *PetAPIController) FilterPetsByCategory(w http.ResponseWriter, r *http.R
 		for _, param := range paramSplits {
 			paramEnum, err := NewSpeciesFromValue(param)
 			if err != nil {
-				c.errorHandler(w, r, &ParsingError{Err: err}, nil)
+				c.errorHandler(w, r, &ParsingError{Param: "notSpecies", Err: err}, nil)
 				return
 			}
 			notSpeciesParam = append(notSpeciesParam, paramEnum)
@@ -270,7 +270,7 @@ func (c *PetAPIController) FindPetsByTags(w http.ResponseWriter, r *http.Request
 	if query.Has("bornAfter"){
 		param, err := parseTime(query.Get("bornAfter"))
 		if err != nil {
-			c.errorHandler(w, r, &ParsingError{Err: err}, nil)
+			c.errorHandler(w, r, &ParsingError{Param: "bornAfter", Err: err}, nil)
 			return
 		}
 
@@ -283,7 +283,7 @@ func (c *PetAPIController) FindPetsByTags(w http.ResponseWriter, r *http.Request
 	if query.Has("bornBefore"){
 		param, err := parseTime(query.Get("bornBefore"))
 		if err != nil {
-			c.errorHandler(w, r, &ParsingError{Err: err}, nil)
+			c.errorHandler(w, r, &ParsingError{Param: "bornBefore", Err: err}, nil)
 			return
 		}
 
@@ -315,7 +315,7 @@ func (c *PetAPIController) GetPetById(w http.ResponseWriter, r *http.Request) {
 		WithRequire[int64](parseInt64),
 	)
 	if err != nil {
-		c.errorHandler(w, r, &ParsingError{Err: err}, nil)
+		c.errorHandler(w, r, &ParsingError{Param: "petId", Err: err}, nil)
 		return
 	}
 	result, err := c.service.GetPetById(r.Context(), petIdParam)
@@ -336,7 +336,7 @@ func (c *PetAPIController) GetPetImageById(w http.ResponseWriter, r *http.Reques
 		WithRequire[int64](parseInt64),
 	)
 	if err != nil {
-		c.errorHandler(w, r, &ParsingError{Err: err}, nil)
+		c.errorHandler(w, r, &ParsingError{Param: "petId", Err: err}, nil)
 		return
 	}
 	result, err := c.service.GetPetImageById(r.Context(), petIdParam)
@@ -354,7 +354,7 @@ func (c *PetAPIController) GetPetsByTime(w http.ResponseWriter, r *http.Request)
 	params := mux.Vars(r)
 	createdTimeParam, err := parseTime(params["createdTime"])
 	if err != nil {
-		c.errorHandler(w, r, &ParsingError{Err: err}, nil)
+		c.errorHandler(w, r, &ParsingError{Param: "createdTime", Err: err}, nil)
 		return
 	}
 	result, err := c.service.GetPetsByTime(r.Context(), createdTimeParam)
@@ -381,7 +381,7 @@ func (c *PetAPIController) GetPetsUsingBooleanQueryParameters(w http.ResponseWri
 			WithParse[bool](parseBool),
 		)
 		if err != nil {
-			c.errorHandler(w, r, &ParsingError{Err: err}, nil)
+			c.errorHandler(w, r, &ParsingError{Param: "expr", Err: err}, nil)
 			return
 		}
 
@@ -397,7 +397,7 @@ func (c *PetAPIController) GetPetsUsingBooleanQueryParameters(w http.ResponseWri
 			WithParse[bool](parseBool),
 		)
 		if err != nil {
-			c.errorHandler(w, r, &ParsingError{Err: err}, nil)
+			c.errorHandler(w, r, &ParsingError{Param: "grouping", Err: err}, nil)
 			return
 		}
 
@@ -411,7 +411,7 @@ func (c *PetAPIController) GetPetsUsingBooleanQueryParameters(w http.ResponseWri
 			WithParse[bool](parseBool),
 		)
 		if err != nil {
-			c.errorHandler(w, r, &ParsingError{Err: err}, nil)
+			c.errorHandler(w, r, &ParsingError{Param: "inactive", Err: err}, nil)
 			return
 		}
 
@@ -444,7 +444,7 @@ func (c *PetAPIController) SearchPet(w http.ResponseWriter, r *http.Request) {
 			WithParse[int64](parseInt64),
 		)
 		if err != nil {
-			c.errorHandler(w, r, &ParsingError{Err: err}, nil)
+			c.errorHandler(w, r, &ParsingError{Param: "age", Err: err}, nil)
 			return
 		}
 
@@ -458,7 +458,7 @@ func (c *PetAPIController) SearchPet(w http.ResponseWriter, r *http.Request) {
 			WithParse[float32](parseFloat32),
 		)
 		if err != nil {
-			c.errorHandler(w, r, &ParsingError{Err: err}, nil)
+			c.errorHandler(w, r, &ParsingError{Param: "price", Err: err}, nil)
 			return
 		}
 
@@ -469,7 +469,7 @@ func (c *PetAPIController) SearchPet(w http.ResponseWriter, r *http.Request) {
 	if query.Has("bornAfter"){
 		param, err := parseTime(query.Get("bornAfter"))
 		if err != nil {
-			c.errorHandler(w, r, &ParsingError{Err: err}, nil)
+			c.errorHandler(w, r, &ParsingError{Param: "bornAfter", Err: err}, nil)
 			return
 		}
 
@@ -483,7 +483,7 @@ func (c *PetAPIController) SearchPet(w http.ResponseWriter, r *http.Request) {
 			WithParse[bool](parseBool),
 		)
 		if err != nil {
-			c.errorHandler(w, r, &ParsingError{Err: err}, nil)
+			c.errorHandler(w, r, &ParsingError{Param: "old", Err: err}, nil)
 			return
 		}
 
@@ -539,7 +539,7 @@ func (c *PetAPIController) UpdatePetWithForm(w http.ResponseWriter, r *http.Requ
 		WithRequire[int64](parseInt64),
 	)
 	if err != nil {
-		c.errorHandler(w, r, &ParsingError{Err: err}, nil)
+		c.errorHandler(w, r, &ParsingError{Param: "petId", Err: err}, nil)
 		return
 	}
 	
@@ -570,7 +570,7 @@ func (c *PetAPIController) UploadFile(w http.ResponseWriter, r *http.Request) {
 		WithRequire[int64](parseInt64),
 	)
 	if err != nil {
-		c.errorHandler(w, r, &ParsingError{Err: err}, nil)
+		c.errorHandler(w, r, &ParsingError{Param: "petId", Err: err}, nil)
 		return
 	}
 	
@@ -583,7 +583,7 @@ func (c *PetAPIController) UploadFile(w http.ResponseWriter, r *http.Request) {
 	{
 		param, err := ReadFormFileToTempFile(r, "file")
 		if err != nil {
-			c.errorHandler(w, r, &ParsingError{Err: err}, nil)
+			c.errorHandler(w, r, &ParsingError{Param: "file", Err: err}, nil)
 			return
 		}
 
@@ -613,7 +613,7 @@ func (c *PetAPIController) UploadFileArrayOfFiles(w http.ResponseWriter, r *http
 		WithRequire[int64](parseInt64),
 	)
 	if err != nil {
-		c.errorHandler(w, r, &ParsingError{Err: err}, nil)
+		c.errorHandler(w, r, &ParsingError{Param: "petId", Err: err}, nil)
 		return
 	}
 	
@@ -623,7 +623,7 @@ func (c *PetAPIController) UploadFileArrayOfFiles(w http.ResponseWriter, r *http
 	{
 		param, err := ReadFormFilesToTempFiles(r, "files")
 		if err != nil {
-			c.errorHandler(w, r, &ParsingError{Err: err}, nil)
+			c.errorHandler(w, r, &ParsingError{Param: "files", Err: err}, nil)
 			return
 		}
 

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

@@ -114,7 +114,7 @@ func (c *StoreAPIController) GetOrderById(w http.ResponseWriter, r *http.Request
 		WithMaximum[int64](5),
 	)
 	if err != nil {
-		c.errorHandler(w, r, &ParsingError{Err: err}, nil)
+		c.errorHandler(w, r, &ParsingError{Param: "orderId", Err: err}, nil)
 		return
 	}
 	result, err := c.service.GetOrderById(r.Context(), orderIdParam)

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

@@ -191,7 +191,7 @@ func (c *UserAPIController) DeleteUser(w http.ResponseWriter, r *http.Request) {
 			WithParse[bool](parseBool),
 		)
 		if err != nil {
-			c.errorHandler(w, r, &ParsingError{Err: err}, nil)
+			c.errorHandler(w, r, &ParsingError{Param: "boolean_test", Err: err}, nil)
 			return
 		}
 
@@ -258,7 +258,7 @@ func (c *UserAPIController) LoginUser(w http.ResponseWriter, r *http.Request) {
 			WithParse[bool](parseBool),
 		)
 		if err != nil {
-			c.errorHandler(w, r, &ParsingError{Err: err}, nil)
+			c.errorHandler(w, r, &ParsingError{Param: "boolean_test", Err: err}, nil)
 			return
 		}
 

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

@@ -23,7 +23,8 @@ var (
 
 // ParsingError indicates that an error has occurred when parsing request parameters
 type ParsingError struct {
-	Err error
+	Param string
+	Err   error
 }
 
 func (e *ParsingError) Unwrap() error {
@@ -31,7 +32,11 @@ func (e *ParsingError) Unwrap() error {
 }
 
 func (e *ParsingError) Error() string {
-	return e.Err.Error()
+	if e.Param == "" {
+		return e.Err.Error()
+	} else {
+		return e.Param + ": " + e.Err.Error()
+	}
 }
 
 // RequiredError indicates that an error has occurred when parsing request parameters