Reduce duplication, tighten types in Watcher backends, remove anymatc…

…h dependency

Differential Revision: D67259981

packages/metro-file-map/package.json

@@ -13,7 +13,6 @@
   },
   "license": "MIT",
   "dependencies": {
-    "anymatch": "^3.0.3",
     "debug": "^2.2.0",
     "fb-watchman": "^2.0.0",
     "flow-enums-runtime": "^0.0.6",

packages/metro-file-map/src/watchers/FSEventsWatcher.js

@@ -9,24 +9,22 @@
  */
 
 import type {ChangeEventMetadata} from '../flow-types';
-import type {Stats} from 'fs';
 // $FlowFixMe[cannot-resolve-module] - Optional, Darwin only
 // $FlowFixMe[untyped-type-import]
 import type {FSEvents} from 'fsevents';
 
-import {isIncluded, typeFromStat} from './common';
-// $FlowFixMe[untyped-import] - anymatch
-import anymatch from 'anymatch';
+import {
+  isIncluded,
+  posixPathMatchesPattern,
+  recReaddir,
+  typeFromStat,
+} from './common';
 import EventEmitter from 'events';
 import {promises as fsPromises} from 'fs';
 import * as path from 'path';
-// $FlowFixMe[untyped-import] - walker
-import walker from 'walker';
 
 const debug = require('debug')('Metro:FSEventsWatcher');
 
-type Matcher = typeof anymatch.Matcher;
-
 // $FlowFixMe[value-as-type]
 let fsevents: ?FSEvents = null;
 try {
@@ -54,7 +52,7 @@ type FsEventsWatcherEvent =
  */
 export default class FSEventsWatcher extends EventEmitter {
   +root: string;
-  +ignored: ?Matcher;
+  +ignored: ?RegExp;
   +glob: $ReadOnlyArray<string>;
   +dot: boolean;
   +doIgnore: (path: string) => boolean;
@@ -66,38 +64,14 @@ export default class FSEventsWatcher extends EventEmitter {
     return fsevents != null;
   }
 
-  static _normalizeProxy(
-    callback: (normalizedPath: string, stats: Stats) => void,
-  ): (filepath: string, stats: Stats) => void {
-    return (filepath: string, stats: Stats): void =>
-      callback(path.normalize(filepath), stats);
-  }
-
-  static _recReaddir(
-    dir: string,
-    dirCallback: (normalizedPath: string, stats: Stats) => void,
-    fileCallback: (normalizedPath: string, stats: Stats) => void,
-    symlinkCallback: (normalizedPath: string, stats: Stats) => void,
-    endCallback: () => void,
-    // $FlowFixMe[unclear-type] Add types for callback
-    errorCallback: Function,
-    ignored?: Matcher,
-  ) {
-    walker(dir)
-      .filterDir(
-        (currentDir: string) => !ignored || !anymatch(ignored, currentDir),
-      )
-      .on('dir', FSEventsWatcher._normalizeProxy(dirCallback))
-      .on('file', FSEventsWatcher._normalizeProxy(fileCallback))
-      .on('symlink', FSEventsWatcher._normalizeProxy(symlinkCallback))
-      .on('error', errorCallback)
-      .on('end', endCallback);
-  }
-
   constructor(
     dir: string,
-    opts: $ReadOnly<{
-      ignored?: Matcher,
+    {
+      ignored,
+      glob,
+      dot,
+    }: $ReadOnly<{
+      ignored?: ?RegExp,
       glob: string | $ReadOnlyArray<string>,
       dot: boolean,
       ...
@@ -111,10 +85,12 @@ export default class FSEventsWatcher extends EventEmitter {
 
     super();
 
-    this.dot = opts.dot || false;
-    this.ignored = opts.ignored;
-    this.glob = Array.isArray(opts.glob) ? opts.glob : [opts.glob];
-    this.doIgnore = opts.ignored ? anymatch(opts.ignored) : () => false;
+    this.dot = dot || false;
+    this.ignored = ignored;
+    this.glob = Array.isArray(glob) ? glob : [glob];
+    this.doIgnore = ignored
+      ? (filePath: string) => posixPathMatchesPattern(ignored, filePath)
+      : () => false;
 
     this.root = path.resolve(dir);
 
@@ -128,10 +104,10 @@ export default class FSEventsWatcher extends EventEmitter {
 
     this._tracked = new Set();
     const trackPath = (filePath: string) => {
-      this._tracked.add(filePath);
+      this._tracked.add(path.normalize(filePath));
     };
     this.watcherInitialReaddirPromise = new Promise(resolve => {
-      FSEventsWatcher._recReaddir(
+      recReaddir(
         this.root,
         trackPath,
         trackPath,

packages/metro-file-map/src/watchers/NodeWatcher.js

@@ -48,7 +48,7 @@ module.exports = class NodeWatcher extends EventEmitter {
   doIgnore: string => boolean;
   dot: boolean;
   globs: $ReadOnlyArray<string>;
-  ignored: ?(boolean | RegExp);
+  ignored: ?RegExp;
   root: string;
   watched: {[key: string]: FSWatcher, __proto__: null};
   watchmanDeferStates: $ReadOnlyArray<string>;

packages/metro-file-map/src/watchers/__tests__/WatchmanWatcher-test.js

@@ -36,7 +36,7 @@ describe('WatchmanWatcher', () => {
   test('initializes with watch-project, clock, subscribe', () => {
     const watchmanWatcher = new WatchmanWatcher('/project/subdir/js', {
       dot: true,
-      ignored: false,
+      ignored: null,
       glob: ['**/*.js'],
       watchmanDeferStates: ['busy'],
     });
@@ -86,7 +86,7 @@ describe('WatchmanWatcher', () => {
     beforeEach(() => {
       watchmanWatcher = new WatchmanWatcher('/project/subdir/js', {
         dot: true,
-        ignored: false,
+        ignored: null,
         glob: ['**/*.js'],
         watchmanDeferStates: ['busy'],
       });

packages/metro-file-map/src/watchers/common.js

@@ -19,8 +19,6 @@
 import type {ChangeEventMetadata} from '../flow-types';
 import type {Stats} from 'fs';
 
-// $FlowFixMe[untyped-import] - Write libdefs for `anymatch`
-const anymatch = require('anymatch');
 // $FlowFixMe[untyped-import] - Write libdefs for `micromatch`
 const micromatch = require('micromatch');
 const platform = require('os').platform();
@@ -39,7 +37,7 @@ export const ALL_EVENT = 'all';
 export type WatcherOptions = $ReadOnly<{
   glob: $ReadOnlyArray<string>,
   dot: boolean,
-  ignored: boolean | RegExp,
+  ignored: ?RegExp,
   watchmanDeferStates: $ReadOnlyArray<string>,
   watchman?: mixed,
   watchmanPath?: string,
@@ -49,7 +47,7 @@ interface Watcher {
   doIgnore: string => boolean;
   dot: boolean;
   globs: $ReadOnlyArray<string>;
-  ignored?: ?(boolean | RegExp);
+  ignored?: ?RegExp;
   watchmanDeferStates: $ReadOnlyArray<string>;
   watchmanPath?: ?string;
 }
@@ -68,16 +66,16 @@ export const assignOptions = function (
 ): WatcherOptions {
   watcher.globs = opts.glob ?? [];
   watcher.dot = opts.dot ?? false;
-  watcher.ignored = opts.ignored ?? false;
+  watcher.ignored = opts.ignored ?? null;
   watcher.watchmanDeferStates = opts.watchmanDeferStates;
 
   if (!Array.isArray(watcher.globs)) {
     watcher.globs = [watcher.globs];
   }
-  watcher.doIgnore =
-    opts.ignored != null && opts.ignored !== false
-      ? anymatch(opts.ignored)
-      : () => false;
+  const ignored = watcher.ignored;
+  watcher.doIgnore = ignored
+    ? filePath => ignored.test(toPosixSeparators(filePath))
+    : () => false;
 
   if (opts.watchman == true && opts.watchmanPath != null) {
     watcher.watchmanPath = opts.watchmanPath;
@@ -107,6 +105,26 @@ export function isIncluded(
   return micromatch.some(relativePath, globs, {dot});
 }
 
+const toPosixSeparators: (filePath: string) => string =
+  path.sep === '/'
+    ? filePath => filePath
+    : filePath => filePath.replaceAll(path.sep, '/');
+
+/**
+ * Whether the given filePath matches the given RegExp, after converting
+ * (on Windows only) system separators to posix separators.
+ *
+ * Conversion to posix is for backwards compatibility with the previous
+ * anymatch matcher, which normlises all inputs[1]. This may not be consistent
+ * with other parts of metro-file-map.
+ *
+ * [1]: https://github.com/micromatch/anymatch/blob/3.1.1/index.js#L50
+ */
+export const posixPathMatchesPattern = (
+  pattern: RegExp,
+  filePath: string,
+): boolean => pattern.test(toPosixSeparators(filePath));
+
 /**
  * Traverse a directory recursively calling `callback` on every directory.
  */
@@ -117,10 +135,15 @@ export function recReaddir(
   symlinkCallback: (string, Stats) => void,
   endCallback: () => void,
   errorCallback: Error => void,
-  ignored: ?(boolean | RegExp),
+  ignored: ?RegExp,
 ) {
-  walker(dir)
-    .filterDir(currentDir => !anymatch(ignored, currentDir))
+  const walk = walker(dir);
+  if (ignored) {
+    walk.filterDir(
+      (currentDir: string) => !posixPathMatchesPattern(ignored, currentDir),
+    );
+  }
+  walk
     .on('dir', normalizeProxy(dirCallback))
     .on('file', normalizeProxy(fileCallback))
     .on('symlink', normalizeProxy(symlinkCallback))