feat(http): respect Encoding Object while building requests

This change is specific to OpenAPI 3.x.y.

Refs swagger-api/swagger-ui#4826

src/execute/index.js

@@ -268,7 +268,7 @@ export function buildRequest(options) {
 
   if (req.cookies) {
     // even if no cookies were defined, we need to remove
-    // the cookies key from our request, or many many legacy
+    // the cookies key from our request, or many legacy
     // tests will break.
     delete req.cookies;
   }

src/execute/oas3/build-request.js

@@ -61,7 +61,7 @@ export default function buildRequest(options, req) {
           requestContentType === 'multipart/form-data'
         ) {
           if (typeof requestBody === 'object') {
-            const encoding = (requestBodyDef.content[requestContentType] || {}).encoding || {};
+            const encoding = requestBodyDef.content[requestContentType]?.encoding ?? {};
 
             req.form = {};
             Object.keys(requestBody).forEach((k) => {

src/http/index.js

@@ -190,6 +190,29 @@ const SEPARATORS = {
   pipes: '|',
 };
 
+/**
+ * Specialized sub-class of File class, that only
+ * accepts string data and retain this data in `data`
+ * public property throughout the lifecycle of its instances.
+ *
+ * This sub-class is exclusively used only when Encoding Object
+ * is defined within the Media Type Object (OpenAPI 3.x.y).
+ */
+class FileWithData extends File {
+  constructor(data, name = '', options = {}) {
+    super([data], name, options);
+    this.data = data;
+  }
+
+  valueOf() {
+    return this.data;
+  }
+
+  toString() {
+    return this.valueOf();
+  }
+}
+
 // Formats a key-value and returns an array of key-value pairs.
 //
 // Return value example 1: [['color', 'blue']]
@@ -234,13 +257,20 @@ function formatKeyValue(key, input, skipEncoding = false) {
       });
     }
 
-    if (encoding.contentType) {
-      if (encoding.contentType === 'application/json') {
-        // If value is a string, assume value is already a JSON string
+    if (typeof encoding.contentType === 'string') {
+      if (encoding.contentType.startsWith('application/json')) {
+        // if value is a string, assume value is already a JSON string
         const json = typeof value === 'string' ? value : JSON.stringify(value);
-        return [[encodedKey, encodeFn(json)]];
+        const encodedJson = encodeFn(json);
+        const file = new FileWithData(encodedJson, 'blob', { type: encoding.contentType });
+
+        return [[encodedKey, file]];
       }
-      return [[encodedKey, encodeFn(value.toString())]];
+
+      const encodedData = encodeFn(String(value));
+      const blob = new FileWithData(encodedData, 'blob', { type: encoding.contentType });
+
+      return [[encodedKey, blob]];
     }
 
     // Primitive
@@ -378,10 +408,15 @@ export function encodeFormOrQuery(data) {
   const encodedQuery = Object.keys(data).reduce((result, parameterName) => {
     // eslint-disable-next-line no-restricted-syntax
     for (const [key, value] of formatKeyValue(parameterName, data[parameterName])) {
-      result[key] = value;
+      if (value instanceof FileWithData) {
+        result[key] = value.valueOf();
+      } else {
+        result[key] = value;
+      }
     }
     return result;
   }, {});
+
   return qs.stringify(encodedQuery, { encode: false, indices: false }) || '';
 }
 

test/oas3/execute/build-request.js

@@ -1,3 +1,5 @@
+import { File } from 'formdata-node';
+
 // https://github.com/swagger-api/swagger-js/issues/1116
 import { buildRequest } from '../../../src/execute/index.js';
 
@@ -81,4 +83,135 @@ describe('buildRequest - OAS 3.0.x', () => {
       });
     });
   });
+
+  describe('given Encoding Object to describe multipart/form-data', () => {
+    const spec = {
+      openapi: '3.0.0',
+      paths: {
+        '/upload/': {
+          post: {
+            tags: ['upload'],
+            operationId: 'upload',
+            requestBody: {
+              required: true,
+              content: {
+                'multipart/form-data': {
+                  schema: {
+                    type: 'object',
+                    properties: {
+                      options: {
+                        type: 'object',
+                        properties: {
+                          some_array: {
+                            type: 'array',
+                            items: {
+                              type: 'string',
+                            },
+                          },
+                          max_bar: {
+                            type: 'integer',
+                            default: 300,
+                          },
+                        },
+                      },
+                    },
+                  },
+                  encoding: {
+                    options: {
+                      contentType: 'application/json; charset=utf-8',
+                    },
+                  },
+                },
+              },
+            },
+          },
+        },
+      },
+    };
+
+    test('should attach mime type to appropriate boundaries', async () => {
+      const options = {
+        some_array: ['string'],
+        max_bar: 300,
+      };
+      const req = buildRequest({
+        spec,
+        operationId: 'upload',
+        requestBody: { options },
+      });
+      const file = req.formdata.get('options');
+      const json = await file.text();
+
+      expect(json).toStrictEqual(JSON.stringify(options));
+      expect(file).toBeInstanceOf(File);
+      expect(file.valueOf()).toStrictEqual(JSON.stringify(options));
+      expect(file.type).toStrictEqual('application/json; charset=utf-8');
+    });
+  });
+
+  describe('given Encoding Object to describe application/x-www-form-urlencoded', () => {
+    const spec = {
+      openapi: '3.0.0',
+      paths: {
+        '/upload/': {
+          post: {
+            tags: ['upload'],
+            operationId: 'upload',
+            requestBody: {
+              required: true,
+              content: {
+                'application/x-www-form-urlencoded': {
+                  schema: {
+                    type: 'object',
+                    properties: {
+                      options: {
+                        type: 'object',
+                        properties: {
+                          some_array: {
+                            type: 'array',
+                            items: {
+                              type: 'string',
+                            },
+                          },
+                          max_bar: {
+                            type: 'integer',
+                            default: 300,
+                          },
+                        },
+                      },
+                    },
+                  },
+                  encoding: {
+                    options: {
+                      contentType: 'application/json; charset=utf-8',
+                    },
+                  },
+                },
+              },
+            },
+          },
+        },
+      },
+    };
+
+    test('should create proper application/x-www-form-urlencoded request', async () => {
+      const options = {
+        some_array: ['string'],
+        max_bar: 300,
+      };
+      const req = buildRequest({
+        spec,
+        operationId: 'upload',
+        requestBody: { options },
+      });
+
+      expect(req).toEqual({
+        url: '/upload/',
+        credentials: 'same-origin',
+        headers: { 'Content-Type': 'application/x-www-form-urlencoded' },
+        method: 'POST',
+        body: 'options=%7B%22some_array%22%3A%5B%22string%22%5D%2C%22max_bar%22%3A300%7D',
+      });
+    });
+  });
 });