feat: added mimeTypeDefault option (#1527)

Author: alexander-akait

README.md

@@ -60,17 +60,18 @@ See [below](#other-servers) for an example of use with fastify.
 
 ## Options
 
-|                    Name                     |           Type            |                    Default                    | Description                                                                                                          |
-| :-----------------------------------------: | :-----------------------: | :-------------------------------------------: | :------------------------------------------------------------------------------------------------------------------- |
-|          **[`methods`](#methods)**          |          `Array`          |              `[ 'GET', 'HEAD' ]`              | Allows to pass the list of HTTP request methods accepted by the middleware                                           |
-|          **[`headers`](#headers)**          | `Array\|Object\|Function` |                  `undefined`                  | Allows to pass custom HTTP headers on each request.                                                                  |
-|            **[`index`](#index)**            |     `Boolean\|String`     |                 `index.html`                  | If `false` (but not `undefined`), the server will not respond to requests to the root URL.                           |
-|        **[`mimeTypes`](#mimetypes)**        |         `Object`          |                  `undefined`                  | Allows to register custom mime types or extension mappings.                                                          |
-|       **[`publicPath`](#publicpath)**       |         `String`          |  `output.publicPath` (from a configuration)   | The public path that the middleware is bound to.                                                                     |
-|            **[`stats`](#stats)**            | `Boolean\|String\|Object` |        `stats` (from a configuration)         | Stats options object or preset name.                                                                                 |
-| **[`serverSideRender`](#serversiderender)** |         `Boolean`         |                  `undefined`                  | Instructs the module to enable or disable the server-side rendering mode.                                            |
-|      **[`writeToDisk`](#writetodisk)**      |    `Boolean\|Function`    |                    `false`                    | Instructs the module to write files to the configured location on disk as specified in your `webpack` configuration. |
-| **[`outputFileSystem`](#outputfilesystem)** |         `Object`          | [`memfs`](https://github.com/streamich/memfs) | Set the default file system which will be used by webpack as primary destination of generated files.                 |
+|                    Name                     |    Type    |                    Default                    | Description                                                                                          |
+| :-----------------------------------------: | :--------: | :-------------------------------------------: | :--------------------------------------------------------------------------------------------------- | -------------------------------------------------------------------------------------------------------------------- |
+|          **[`methods`](#methods)**          |  `Array`   |              `[ 'GET', 'HEAD' ]`              | Allows to pass the list of HTTP request methods accepted by the middleware                           |
+|          **[`headers`](#headers)**          |  `Array\   |              Object\| Function`               | `undefined`                                                                                          | Allows to pass custom HTTP headers on each request.                                                                  |
+|            **[`index`](#index)**            | `Boolean\  |                    String`                    | `index.html`                                                                                         | If `false` (but not `undefined`), the server will not respond to requests to the root URL.                           |
+|        **[`mimeTypes`](#mimetypes)**        |  `Object`  |                  `undefined`                  | Allows to register custom mime types or extension mappings.                                          |
+|  **[`mimeTypeDefault`](#mimetypedefault)**  |  `String`  |                  `undefined`                  | Allows to register a default mime type when we can't determine the content type.                     |
+|       **[`publicPath`](#publicpath)**       |  `String`  |  `output.publicPath` (from a configuration)   | The public path that the middleware is bound to.                                                     |
+|            **[`stats`](#stats)**            | `Boolean\  |               String\| Object`                | `stats` (from a configuration)                                                                       | Stats options object or preset name.                                                                                 |
+| **[`serverSideRender`](#serversiderender)** | `Boolean`  |                  `undefined`                  | Instructs the module to enable or disable the server-side rendering mode.                            |
+|      **[`writeToDisk`](#writetodisk)**      | `Boolean\  |                   Function`                   | `false`                                                                                              | Instructs the module to write files to the configured location on disk as specified in your `webpack` configuration. |
+| **[`outputFileSystem`](#outputfilesystem)** |  `Object`  | [`memfs`](https://github.com/streamich/memfs) | Set the default file system which will be used by webpack as primary destination of generated files. |
 
 The middleware accepts an `options` Object. The following is a property reference for the Object.
 
@@ -164,6 +165,13 @@ eg. `mimeTypes: { phtml: 'text/html' }`.
 
 Please see the documentation for [`mime-types`](https://github.com/jshttp/mime-types) for more information.
 
+### mimeTypeDefault
+
+Type: `String`  
+Default: `undefined`
+
+This property allows a user to register a default mime type when we can't determine the content type.
+
 ### publicPath
 
 Type: `String`

src/index.js

@@ -80,6 +80,7 @@ const noop = () => {};
  * @template {ServerResponse} ResponseInternal
  * @typedef {Object} Options
  * @property {{[key: string]: string}} [mimeTypes]
+ * @property {string | undefined} [mimeTypeDefault]
  * @property {boolean | ((targetPath: string) => boolean)} [writeToDisk]
  * @property {string} [methods]
  * @property {Headers<RequestInternal, ResponseInternal>} [headers]

src/middleware.js

@@ -146,6 +146,12 @@ function wrapper(context) {
         // https://tools.ietf.org/html/rfc7231#section-3.1.1.5
         if (contentType) {
           setHeaderForResponse(res, "Content-Type", contentType);
+        } else if (context.options.mimeTypeDefault) {
+          setHeaderForResponse(
+            res,
+            "Content-Type",
+            context.options.mimeTypeDefault
+          );
         }
       }
 

src/options.json

@@ -6,6 +6,11 @@
       "link": "https://github.com/webpack/webpack-dev-middleware#mimetypes",
       "type": "object"
     },
+    "mimeTypeDefault": {
+      "description": "Allows a user to register a default mime type when we can't determine the content type.",
+      "link": "https://github.com/webpack/webpack-dev-middleware#mimetypedefault",
+      "type": "string"
+    },
     "writeToDisk": {
       "description": "Allows to write generated files on disk.",
       "link": "https://github.com/webpack/webpack-dev-middleware#writetodisk",

test/middleware.test.js

@@ -2163,6 +2163,52 @@ describe.each([
       });
     });
 
+    describe("mimeTypeDefault option", () => {
+      describe('should set the correct value for "Content-Type" header to unknown MIME type', () => {
+        beforeAll((done) => {
+          const outputPath = path.resolve(__dirname, "./outputs/basic");
+          const compiler = getCompiler({
+            ...webpackConfig,
+            output: {
+              filename: "bundle.js",
+              path: outputPath,
+            },
+          });
+
+          instance = middleware(compiler, {
+            mimeTypeDefault: "text/plain",
+          });
+
+          app = framework();
+          app.use(instance);
+
+          listen = listenShorthand(done);
+
+          req = request(app);
+
+          instance.context.outputFileSystem.mkdirSync(outputPath, {
+            recursive: true,
+          });
+          instance.context.outputFileSystem.writeFileSync(
+            path.resolve(outputPath, "file.unknown"),
+            "welcome"
+          );
+        });
+
+        afterAll(close);
+
+        it('should return the "200" code for the "GET" request to "file.html"', async () => {
+          const response = await req.get("/file.unknown");
+
+          expect(response.statusCode).toEqual(200);
+          expect(
+            response.headers["content-type"].startsWith("text/plain")
+          ).toBe(true);
+          expect(response.text).toEqual("welcome");
+        });
+      });
+    });
+
     describe("watchOptions option", () => {
       describe("should work without value", () => {
         let compiler;

types/index.d.ts

@@ -58,6 +58,7 @@ export = wdm;
  * @template {ServerResponse} ResponseInternal
  * @typedef {Object} Options
  * @property {{[key: string]: string}} [mimeTypes]
+ * @property {string | undefined} [mimeTypeDefault]
  * @property {boolean | ((targetPath: string) => boolean)} [writeToDisk]
  * @property {string} [methods]
  * @property {Headers<RequestInternal, ResponseInternal>} [headers]
@@ -164,6 +165,7 @@ type Options<
         [key: string]: string;
       }
     | undefined;
+  mimeTypeDefault?: string | undefined;
   writeToDisk?: boolean | ((targetPath: string) => boolean) | undefined;
   methods?: string | undefined;
   headers?: Headers<RequestInternal, ResponseInternal>;