Support reserved json name and add tests (#1085)

* Support reserved json name and add tests

* Correct some variable names

* Optimize a logic for assigning a reserved json name to jsonCamelCaseName

* Put a logic for checking if there is a reseved json name in the method of lowerCamelCase

Fixes #1084

protoc-gen-swagger/genswagger/template.go

@@ -17,9 +17,9 @@ import (
 	"github.com/golang/glog"
 	"github.com/golang/protobuf/jsonpb"
 	"github.com/golang/protobuf/proto"
-	structpb "github.com/golang/protobuf/ptypes/struct"
 	pbdescriptor "github.com/golang/protobuf/protoc-gen-go/descriptor"
 	gogen "github.com/golang/protobuf/protoc-gen-go/generator"
+	structpb "github.com/golang/protobuf/ptypes/struct"
 	"github.com/grpc-ecosystem/grpc-gateway/protoc-gen-grpc-gateway/descriptor"
 	swagger_options "github.com/grpc-ecosystem/grpc-gateway/protoc-gen-swagger/options"
 )
@@ -621,7 +621,7 @@ func resolveFullyQualifiedNameToSwaggerNames(messages []string, useFQNForSwagger
 var canRegexp = regexp.MustCompile("{([a-zA-Z][a-zA-Z0-9_.]*).*}")
 
 // Swagger expects paths of the form /path/{string_value} but grpc-gateway paths are expected to be of the form /path/{string_value=strprefix/*}. This should reformat it correctly.
-func templateToSwaggerPath(path string, reg *descriptor.Registry) string {
+func templateToSwaggerPath(path string, reg *descriptor.Registry, fields []*descriptor.Field) string {
 	// It seems like the right thing to do here is to just use
 	// strings.Split(path, "/") but that breaks badly when you hit a url like
 	// /{my_field=prefix/*}/ and end up with 2 sections representing my_field.
@@ -650,7 +650,7 @@ func templateToSwaggerPath(path string, reg *descriptor.Registry) string {
 			if reg.GetUseJSONNamesForFields() &&
 				len(jsonBuffer) > 1 {
 				jsonSnakeCaseName := string(jsonBuffer[1:])
-				jsonCamelCaseName := string(lowerCamelCase(jsonSnakeCaseName))
+				jsonCamelCaseName := string(lowerCamelCase(jsonSnakeCaseName, fields))
 				prev := string(buffer[:len(buffer)-len(jsonSnakeCaseName)-2])
 				buffer = strings.Join([]string{prev, "{", jsonCamelCaseName, "}"}, "")
 				jsonBuffer = ""
@@ -769,7 +769,7 @@ func renderServices(services []*descriptor.Service, paths swaggerPathsObject, re
 					}
 					parameterString := parameter.String()
 					if reg.GetUseJSONNamesForFields() {
-						parameterString = lowerCamelCase(parameterString)
+						parameterString = lowerCamelCase(parameterString, meth.RequestType.Fields)
 					}
 					parameters = append(parameters, swaggerParameterObject{
 						Name:        parameterString,
@@ -836,7 +836,7 @@ func renderServices(services []*descriptor.Service, paths swaggerPathsObject, re
 					parameters = append(parameters, queryParams...)
 				}
 
-				pathItemObject, ok := paths[templateToSwaggerPath(b.PathTmpl.Template, reg)]
+				pathItemObject, ok := paths[templateToSwaggerPath(b.PathTmpl.Template, reg, meth.RequestType.Fields)]
 				if !ok {
 					pathItemObject = swaggerPathItemObject{}
 				}
@@ -1002,7 +1002,7 @@ func renderServices(services []*descriptor.Service, paths swaggerPathsObject, re
 					pathItemObject.Patch = operationObject
 					break
 				}
-				paths[templateToSwaggerPath(b.PathTmpl.Template, reg)] = pathItemObject
+				paths[templateToSwaggerPath(b.PathTmpl.Template, reg, meth.RequestType.Fields)] = pathItemObject
 			}
 		}
 	}
@@ -1802,8 +1802,13 @@ func addCustomRefs(d swaggerDefinitionsObject, reg *descriptor.Registry, refs re
 	addCustomRefs(d, reg, refs)
 }
 
-func lowerCamelCase(parameter string) string {
-	parameterString := gogen.CamelCase(parameter)
+func lowerCamelCase(fieldName string, fields []*descriptor.Field) string {
+	for _, oneField := range fields {
+		if oneField.GetName() == fieldName {
+			return oneField.GetJsonName()
+		}
+	}
+	parameterString := gogen.CamelCase(fieldName)
 	builder := &strings.Builder{}
 	builder.WriteString(strings.ToLower(string(parameterString[0])))
 	builder.WriteString(parameterString[1:])

protoc-gen-swagger/genswagger/template_test.go

@@ -986,6 +986,15 @@ func TestApplyTemplateRequestWithUnusedReferences(t *testing.T) {
 	}
 }
 
+func generateFieldsForJSONReservedName() []*descriptor.Field {
+	fields := make([]*descriptor.Field, 0)
+	fieldName := string("json_name")
+	fieldJSONName := string("jsonNAME")
+	fieldDescriptor := protodescriptor.FieldDescriptorProto{Name: &fieldName, JsonName: &fieldJSONName}
+	field := &descriptor.Field{FieldDescriptorProto: &fieldDescriptor}
+	return append(fields, field)
+}
+
 func TestTemplateWithJsonCamelCase(t *testing.T) {
 	var tests = []struct {
 		input    string
@@ -1002,11 +1011,12 @@ func TestTemplateWithJsonCamelCase(t *testing.T) {
 		{"test/{ab}", "test/{ab}"},
 		{"test/{a_a}", "test/{aA}"},
 		{"test/{ab_c}", "test/{abC}"},
+		{"test/{json_name}", "test/{jsonNAME}"},
 	}
 	reg := descriptor.NewRegistry()
 	reg.SetUseJSONNamesForFields(true)
 	for _, data := range tests {
-		actual := templateToSwaggerPath(data.input, reg)
+		actual := templateToSwaggerPath(data.input, reg, generateFieldsForJSONReservedName())
 		if data.expected != actual {
 			t.Errorf("Expected templateToSwaggerPath(%v) = %v, actual: %v", data.input, data.expected, actual)
 		}
@@ -1028,11 +1038,12 @@ func TestTemplateWithoutJsonCamelCase(t *testing.T) {
 		{"test/{a}", "test/{a}"},
 		{"test/{ab}", "test/{ab}"},
 		{"test/{a_a}", "test/{a_a}"},
+		{"test/{json_name}", "test/{json_name}"},
 	}
 	reg := descriptor.NewRegistry()
 	reg.SetUseJSONNamesForFields(false)
 	for _, data := range tests {
-		actual := templateToSwaggerPath(data.input, reg)
+		actual := templateToSwaggerPath(data.input, reg, generateFieldsForJSONReservedName())
 		if data.expected != actual {
 			t.Errorf("Expected templateToSwaggerPath(%v) = %v, actual: %v", data.input, data.expected, actual)
 		}
@@ -1064,14 +1075,14 @@ func TestTemplateToSwaggerPath(t *testing.T) {
 	reg := descriptor.NewRegistry()
 	reg.SetUseJSONNamesForFields(false)
 	for _, data := range tests {
-		actual := templateToSwaggerPath(data.input, reg)
+		actual := templateToSwaggerPath(data.input, reg, generateFieldsForJSONReservedName())
 		if data.expected != actual {
 			t.Errorf("Expected templateToSwaggerPath(%v) = %v, actual: %v", data.input, data.expected, actual)
 		}
 	}
 	reg.SetUseJSONNamesForFields(true)
 	for _, data := range tests {
-		actual := templateToSwaggerPath(data.input, reg)
+		actual := templateToSwaggerPath(data.input, reg, generateFieldsForJSONReservedName())
 		if data.expected != actual {
 			t.Errorf("Expected templateToSwaggerPath(%v) = %v, actual: %v", data.input, data.expected, actual)
 		}
@@ -1086,7 +1097,7 @@ func BenchmarkTemplateToSwaggerPath(b *testing.B) {
 		reg.SetUseJSONNamesForFields(false)
 
 		for i := 0; i < b.N; i++ {
-			_ = templateToSwaggerPath(input, reg)
+			_ = templateToSwaggerPath(input, reg, generateFieldsForJSONReservedName())
 		}
 	})
 
@@ -1095,7 +1106,7 @@ func BenchmarkTemplateToSwaggerPath(b *testing.B) {
 		reg.SetUseJSONNamesForFields(true)
 
 		for i := 0; i < b.N; i++ {
-			_ = templateToSwaggerPath(input, reg)
+			_ = templateToSwaggerPath(input, reg, generateFieldsForJSONReservedName())
 		}
 	})
 }
@@ -1171,14 +1182,14 @@ func TestFQMNtoSwaggerName(t *testing.T) {
 	reg := descriptor.NewRegistry()
 	reg.SetUseJSONNamesForFields(false)
 	for _, data := range tests {
-		actual := templateToSwaggerPath(data.input, reg)
+		actual := templateToSwaggerPath(data.input, reg, generateFieldsForJSONReservedName())
 		if data.expected != actual {
 			t.Errorf("Expected templateToSwaggerPath(%v) = %v, actual: %v", data.input, data.expected, actual)
 		}
 	}
 	reg.SetUseJSONNamesForFields(true)
 	for _, data := range tests {
-		actual := templateToSwaggerPath(data.input, reg)
+		actual := templateToSwaggerPath(data.input, reg, generateFieldsForJSONReservedName())
 		if data.expected != actual {
 			t.Errorf("Expected templateToSwaggerPath(%v) = %v, actual: %v", data.input, data.expected, actual)
 		}