[php] 2.3 - fix form params json encoding (#5701)

* fixed tests expectations not compatible with phpunit 4

* added test and endpoint definition, updated template

* regenerated sample

* regenerated security sample

modules/swagger-codegen/src/main/resources/php/api.mustache

@@ -222,6 +222,17 @@ use {{invokerPackage}}\ObjectSerializer;
         }
         {{/bodyParams}}
 
+        if ($multipart) {
+            $headers= $this->headerSelector->selectHeadersForMultipart(
+                [{{#produces}}'{{{mediaType}}}'{{#hasMore}}, {{/hasMore}}{{/produces}}]
+            );
+        } else {
+            $headers = $this->headerSelector->selectHeaders(
+                [{{#produces}}'{{{mediaType}}}'{{#hasMore}}, {{/hasMore}}{{/produces}}],
+                [{{#consumes}}'{{{mediaType}}}'{{#hasMore}}, {{/hasMore}}{{/consumes}}]
+            );
+        }
+
         // for model (json/xml)
         if (isset($_tempBody)) {
             $httpBody = $_tempBody; // $_tempBody is the method argument, if present
@@ -237,22 +248,14 @@ use {{invokerPackage}}\ObjectSerializer;
                 }
                 $httpBody = new MultipartStream($multipartContents); // for HTTP post (form)
 
+            } elseif ($headers['Content-Type'] === 'application/json') {
+                $httpBody = \GuzzleHttp\json_encode($formParams);
+
             } else {
                 $httpBody = \GuzzleHttp\Psr7\build_query($formParams); // for HTTP post (form)
             }
         }
 
-        if ($httpBody instanceof MultipartStream) {
-            $headers= $this->headerSelector->selectHeadersForMultipart(
-                [{{#produces}}'{{{mediaType}}}'{{#hasMore}}, {{/hasMore}}{{/produces}}]
-            );
-        } else {
-            $headers = $this->headerSelector->selectHeaders(
-                [{{#produces}}'{{{mediaType}}}'{{#hasMore}}, {{/hasMore}}{{/produces}}],
-                [{{#consumes}}'{{{mediaType}}}'{{#hasMore}}, {{/hasMore}}{{/consumes}}]
-            );
-        }
-
         {{#authMethods}}
         {{#isApiKey}}
         // this endpoint requires API key authentication

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

@@ -872,6 +872,29 @@ paths:
           description: Output composite
           schema:
             $ref: '#/definitions/OuterComposite'
+  /fake/jsonFormData:
+    get:
+      tags:
+        - fake
+      summary: test json serialization of form data
+      description: ''
+      operationId: testJsonFormData
+      consumes:
+        - application/json
+      parameters:
+        - name: param
+          in: formData
+          description: field1
+          required: true
+          type: string
+        - name: param2
+          in: formData
+          description: field2
+          required: true
+          type: string
+      responses:
+        '200':
+          description: successful operation
 securityDefinitions:
   petstore_auth:
     type: oauth2