Type serve-static and document /debugger-frontend (#40765)

Summary:
Pull Request resolved: https://github.com/facebook/react-native/pull/40765

Types based on https://github.com/DefinitelyTyped/DefinitelyTyped/blob/master/types/serve-static/index.d.ts.

Changelog: [Internal]

Reviewed By: motiz88

Differential Revision: D50084591

fbshipit-source-id: 92fd833d90dfc5acbd3be0476f1da34e5742a732

flow-typed/npm/serve-static_v1.x.x.js

@@ -0,0 +1,122 @@
+/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ *
+ * @flow strict
+ * @format
+ * @oncall react_native
+ */
+
+declare module 'serve-static' {
+  import type {NextHandleFunction} from 'connect';
+  import type http from 'http';
+
+  declare export type Options = $ReadOnly<{
+    /**
+     * Enable or disable accepting ranged requests, defaults to true. Disabling
+     * this will not send `Accept-Ranges` and ignore the contents of the
+     * `Range` request header.
+     */
+    acceptRanges?: boolean,
+
+    /**
+     * Enable or disable setting `Cache-Control` response header, defaults to
+     * true. Disabling this will ignore the `immutable` and `maxAge` options.
+     */
+    cacheControl?: boolean,
+
+    /**
+     * Set how "dotfiles" are treated when encountered. A dotfile is a file or
+     * directory that begins with a dot (".").
+     *
+     * Note this check is done on the path itself without checking if the path
+     * actually exists on the disk. If `root` is specified, only the dotfiles
+     * above the root are checked (i.e. the root itself can be within a dotfile
+     * when when set to "deny").
+     *
+     * The default value is 'ignore'.
+     *
+     * 'allow' No special treatment for dotfiles
+     * 'deny' Send a 403 for any request for a dotfile
+     * 'ignore' Pretend like the dotfile does not exist and call next()
+     */
+    dotfiles?: string,
+
+    /**
+     * Enable or disable etag generation, defaults to true.
+     */
+    etag?: boolean,
+
+    /**
+     * Set file extension fallbacks. When set, if a file is not found, the
+     * given extensions will be added to the file name and search for.
+     * The first that exists will be served. Example: ['html', 'htm'].
+     *
+     * The default value is false.
+     */
+    extensions?: Array<string> | false,
+
+    /**
+     * Let client errors fall-through as unhandled requests, otherwise forward
+     * a client error.
+     *
+     * The default value is true.
+     */
+    fallthrough?: boolean,
+
+    /**
+     * Enable or disable the immutable directive in the `Cache-Control` response
+     * header.
+     *
+     * If enabled, the `maxAge` option should also be specified to enable
+     * caching. The immutable directive will prevent supported clients from
+     * making conditional requests during the life of the maxAge option to
+     * check if the file has changed.
+     */
+    immutable?: boolean,
+
+    /**
+     * By default this module will send "index.html" files in response to a
+     * request on a directory. To disable this set false or to supply a new
+     * index pass a string or an array in preferred order.
+     */
+    index?: boolean | string | Array<string>,
+
+    /**
+     * Enable or disable `Last-Modified` header, defaults to true. Uses the file
+     * system's last modified value.
+     */
+    lastModified?: boolean,
+
+    /**
+     * Provide a max-age in milliseconds for http caching, defaults to 0. This
+     * can also be a string accepted by the `ms` module.
+     */
+    maxAge?: number | string,
+
+    /**
+     * Redirect to trailing "/" when the pathname is a dir. Defaults to true.
+     */
+    redirect?: boolean,
+
+    /**
+     * Function to set custom headers on response. Alterations to the headers
+     * need to occur synchronously.
+     *
+     * The function is called as `fn(res, path, stat)`, where the arguments are:
+     * `res` the response object
+     * `path` the file path that is being sent
+     * `stat` the stat object of the file that is being sent
+     */
+    setHeaders?: (res: http.ServerResponse, path: string, stat: any) => any,
+  }>;
+
+  declare type serveStatic = (
+    root: string,
+    options?: Options,
+  ) => NextHandleFunction;
+
+  declare module.exports: serveStatic;
+}

packages/dev-middleware/README.md

@@ -58,6 +58,10 @@ Returns the list of available WebSocket targets for all connected React Native a
 
 Returns version metadata used by Chrome DevTools.
 
+#### GET `/debugger-frontend`
+
+Subpaths of this endpoint are reserved to serve the JavaScript debugger frontend.
+
 #### POST `/open-debugger`
 
 Open the JavaScript debugger for a given CDP target (direct Hermes debugging).

packages/dev-middleware/src/createDevMiddleware.js

@@ -18,7 +18,6 @@ import type {Logger} from './types/Logger';
 import reactNativeDebuggerFrontendPath from '@react-native/debugger-frontend';
 import connect from 'connect';
 import path from 'path';
-// $FlowFixMe[untyped-import] TODO: type serve-static
 import serveStaticMiddleware from 'serve-static';
 import openDebuggerMiddleware from './middleware/openDebuggerMiddleware';
 import InspectorProxy from './inspector-proxy/InspectorProxy';