[Golang][client] fix formData file parameter name use (#506)

* support form-data file MIME `name` parameter

* update test spec and Go client for form-data file name

* update samples for ensure-up-to-date

* update mustache template

* update samples for Go client

* improve assignment location

* update samples

Author: grokify

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

@@ -67,9 +67,10 @@ type {{{nickname}}}Opts struct {
 func (a *{{{classname}}}Service) {{{nickname}}}(ctx context.Context{{#hasParams}}, {{/hasParams}}{{#allParams}}{{#required}}{{paramName}} {{{dataType}}}{{#hasMore}}, {{/hasMore}}{{/required}}{{/allParams}}{{#hasOptionalParams}}localVarOptionals *{{{nickname}}}Opts{{/hasOptionalParams}}) ({{#returnType}}{{{returnType}}}, {{/returnType}}*http.Response, error) {
 	var (
 		localVarHttpMethod = strings.ToUpper("{{httpMethod}}")
-		localVarPostBody   interface{}
-		localVarFileName   string
-		localVarFileBytes  []byte
+		localVarPostBody     interface{}
+		localVarFormFileName string
+		localVarFileName     string
+		localVarFileBytes    []byte
 		{{#returnType}}
 		localVarReturnValue {{{returnType}}}
 		{{/returnType}}
@@ -177,6 +178,7 @@ func (a *{{{classname}}}Service) {{{nickname}}}(ctx context.Context{{#hasParams}
 {{#hasFormParams}}
 {{#formParams}}
 {{#isFile}}
+	localVarFormFileName = "{{baseName}}"
 {{#required}}
 	localVarFile := {{paramName}}
 {{/required}}
@@ -254,7 +256,7 @@ func (a *{{{classname}}}Service) {{{nickname}}}(ctx context.Context{{#hasParams}
 
 {{/isApiKey}}
 {{/authMethods}}
-	r, err := a.client.prepareRequest(ctx, localVarPath, localVarHttpMethod, localVarPostBody, localVarHeaderParams, localVarQueryParams, localVarFormParams, localVarFileName, localVarFileBytes)
+	r, err := a.client.prepareRequest(ctx, localVarPath, localVarHttpMethod, localVarPostBody, localVarHeaderParams, localVarQueryParams, localVarFormParams, localVarFormFileName, localVarFileName, localVarFileBytes)
 	if err != nil {
 		return {{#returnType}}localVarReturnValue, {{/returnType}}nil, err
 	}

modules/openapi-generator/src/main/resources/go/client.mustache

@@ -167,6 +167,7 @@ func (c *APIClient) prepareRequest(
 	headerParams map[string]string,
 	queryParams url.Values,
 	formParams url.Values,
+	formFileName string,
 	fileName string,
 	fileBytes []byte) (localVarRequest *http.Request, err error) {
 
@@ -209,7 +210,7 @@ func (c *APIClient) prepareRequest(
 		if len(fileBytes) > 0 && fileName != "" {
 			w.Boundary()
 			//_, fileNm := filepath.Split(fileName)
-			part, err := w.CreateFormFile("file", filepath.Base(fileName))
+			part, err := w.CreateFormFile(formFileName, filepath.Base(fileName))
 			if err != nil {
 				return nil, err
 			}

modules/openapi-generator/src/test/resources/2_0/petstore-with-fake-endpoints-models-for-testing.yaml

@@ -987,7 +987,7 @@ paths:
           description: Additional data to pass to server
           required: false
           type: string
-        - name: file
+        - name: requiredFile
           in: formData
           description: file to upload
           required: true
@@ -1526,7 +1526,7 @@ definitions:
           $ref: "#/definitions/File"
   File:
     type: object
-    desription: 'Must be named `File` for test.'
+    description: 'Must be named `File` for test.'
     properties:
       sourceURI:
         description: 'Test capitalization'

modules/openapi-generator/src/test/resources/3_0/petstore-with-fake-endpoints-models-for-testing.yaml

@@ -1,6 +1,4 @@
 openapi: 3.0.0
-servers:
-  - url: 'http://petstore.swagger.io:80/v2'
 info:
   description: >-
     This spec is mainly for testing Petstore server and contains fake endpoints,
@@ -573,7 +571,6 @@ paths:
       parameters:
         - name: enum_header_string_array
           in: header
-          explode: true
           description: Header parameter enum test (string array)
           schema:
             type: array
@@ -964,12 +961,14 @@ paths:
                 additionalMetadata:
                   description: Additional data to pass to server
                   type: string
-                file:
+                requiredFile:
                   description: file to upload
                   type: string
                   format: binary
               required:
-                - file
+                - requiredFile
+servers:
+  - url: 'http://petstore.swagger.io:80/v2'
 components:
   requestBodies:
     UserArray:

samples/client/petstore/go/go-petstore/api/openapi.yaml

@@ -1008,12 +1008,12 @@ paths:
                 additionalMetadata:
                   description: Additional data to pass to server
                   type: string
-                file:
+                requiredFile:
                   description: file to upload
                   format: binary
                   type: string
               required:
-              - file
+              - requiredFile
         required: true
       responses:
         200:
@@ -1507,6 +1507,7 @@ components:
         $ref: '#/components/schemas/Animal'
       type: array
     File:
+      description: Must be named `File` for test.
       example:
         sourceURI: sourceURI
       properties:

samples/client/petstore/go/go-petstore/api_another_fake.go

@@ -34,9 +34,10 @@ To test special tags
 func (a *AnotherFakeApiService) TestSpecialTags(ctx context.Context, client Client) (Client, *http.Response, error) {
 	var (
 		localVarHttpMethod = strings.ToUpper("Patch")
-		localVarPostBody   interface{}
-		localVarFileName   string
-		localVarFileBytes  []byte
+		localVarPostBody     interface{}
+		localVarFormFileName string
+		localVarFileName     string
+		localVarFileBytes    []byte
 		localVarReturnValue Client
 	)
 
@@ -66,7 +67,7 @@ func (a *AnotherFakeApiService) TestSpecialTags(ctx context.Context, client Clie
 	}
 	// body params
 	localVarPostBody = &client
-	r, err := a.client.prepareRequest(ctx, localVarPath, localVarHttpMethod, localVarPostBody, localVarHeaderParams, localVarQueryParams, localVarFormParams, localVarFileName, localVarFileBytes)
+	r, err := a.client.prepareRequest(ctx, localVarPath, localVarHttpMethod, localVarPostBody, localVarHeaderParams, localVarQueryParams, localVarFormParams, localVarFormFileName, localVarFileName, localVarFileBytes)
 	if err != nil {
 		return localVarReturnValue, nil, err
 	}