Flow types for WatchmanWatcher

Summary:
- Expand `fb-watchman` libdefs to include the functionality used by `WatchmanWatcher`
 - Add types to `WatchmanWatcher` and its dependencies
 - Prefix private `WatchmanWatcher` methods with `_`

Motivated by symlink-related work on crawlers and watchers.

Reviewed By: jacdebug

Differential Revision: D39812529

fbshipit-source-id: 65339ac8a06b208f32b6bc629a6d2d53239ccd2c

flow-typed/fb-watchman.js

@@ -10,12 +10,41 @@
  */
 
 declare module 'fb-watchman' {
+  declare type WatchmanClockResponse = $ReadOnly<{
+    clock: string,
+    warning?: string,
+    ...
+  }>;
+
+  declare type WatchmanSubscribeResponse = $ReadOnly<{
+    warning?: string,
+    ...
+  }>;
+
   declare type WatchmanWatchResponse = $ReadOnly<{
     watch: string,
     relative_path: string,
+    warning?: string,
     ...
   }>;
 
+  declare type WatchmanFileChange = $ReadOnly<{
+    name: string,
+    exists: boolean,
+    new: boolean,
+    ...
+  }>;
+
+  declare type WatchmanSubscriptionEvent = {
+    subscription: string,
+    is_fresh_instance: boolean,
+    files: $ReadOnlyArray<WatchmanFileChange>,
+    'state-enter'?: ?string,
+    'state-leave'?: ?string,
+  };
+
+  declare type WatchmanLogEvent = mixed;
+
   declare type SavedStateInfo = $ReadOnly<{
     'manifold-path': ?string,
     'manifold-bucket': ?string,
@@ -103,6 +132,7 @@ declare module 'fb-watchman' {
       }>;
 
   declare type WatchmanQuery = {
+    defer?: $ReadOnlyArray<string>,
     expression?: WatchmanExpression,
     fields: $ReadOnlyArray<string>,
     glob?: $ReadOnlyArray<string>,
@@ -142,7 +172,22 @@ declare module 'fb-watchman' {
       config: ['find', string, string],
       callback: (error: ?Error, response: WatchmanQueryResponse) => void,
     ): void;
+    command(
+      config: ['clock', string],
+      callback: (error: ?Error, response: WatchmanClockResponse) => void,
+    ): void;
+    command(
+      config: ['subscribe', string, string, WatchmanQuery],
+      callback: (error: ?Error, response: WatchmanSubscribeResponse) => void,
+    ): void;
     end(): void;
+
+    on('connect', () => void): void;
+    on('end', () => void): void;
+    on('error', (error: Error) => void): void;
+    on('subscription', (event: WatchmanSubscriptionEvent) => void): void;
+    on('log', (event: WatchmanLogEvent) => void): void;
+    removeAllListeners: (eventName?: string) => void;
   }
 
   declare module.exports: {Client: Class<Client>};

packages/metro-file-map/src/crawlers/watchman/index.js

@@ -64,8 +64,9 @@ module.exports = async function watchmanCrawl({
   abortSignal?.addEventListener('abort', () => client.end());
 
   let clientError;
-  // $FlowFixMe[prop-missing] - Client is not typed as an EventEmitter
-  client.on('error', error => (clientError = makeWatchmanError(error)));
+  client.on('error', error => {
+    clientError = makeWatchmanError(error);
+  });
 
   let didLogWatchmanWaitMessage = false;
 

packages/metro-file-map/src/index.js

@@ -31,6 +31,7 @@ import type {
   SerializableModuleMap,
   WorkerMetadata,
 } from './flow-types';
+import type {WatcherOptions} from './watchers/common';
 import type {Stats} from 'graceful-fs';
 
 import {DiskCacheManager} from './cache/DiskCacheManager';
@@ -47,7 +48,6 @@ import HasteModuleMap from './ModuleMap';
 import FSEventsWatcher from './watchers/FSEventsWatcher';
 // $FlowFixMe[untyped-import] - it's a fork: https://github.com/facebook/jest/pull/10919
 import NodeWatcher from './watchers/NodeWatcher';
-// $FlowFixMe[untyped-import] - WatchmanWatcher
 import WatchmanWatcher from './watchers/WatchmanWatcher';
 import {getSha1, worker} from './worker';
 import EventEmitter from 'events';
@@ -879,7 +879,7 @@ export default class HasteMap extends EventEmitter {
     let mustCopy = true;
 
     const createWatcher = (root: Path): Promise<Watcher> => {
-      const watcher = new WatcherImpl(root, {
+      const watcherOptions: WatcherOptions = {
         dot: true,
         glob: [
           // Ensure we always include package.json files, which are crucial for
@@ -889,7 +889,8 @@ export default class HasteMap extends EventEmitter {
         ],
         ignored: ignorePattern,
         watchmanDeferStates: this._options.watchmanDeferStates,
-      });
+      };
+      const watcher = new WatcherImpl(root, watcherOptions);
 
       return new Promise((resolve, reject) => {
         const rejectTimeout = setTimeout(

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

@@ -1,18 +1,35 @@
 /**
- * vendored from https://github.com/amasad/sane/blob/64ff3a870c42e84f744086884bf55a4f9c22d376/src/utils/recrawl-warning-dedupe.js
+ * 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
  */
 
+/**
+ * Originally vendored from
+ * https://github.com/amasad/sane/blob/64ff3a870c42e84f744086884bf55a4f9c22d376/src/utils/recrawl-warning-dedupe.js
+ */
+
 'use strict';
 
-class RecrawlWarning {
-  constructor(root, count) {
+export default class RecrawlWarning {
+  static RECRAWL_WARNINGS: Array<RecrawlWarning> = [];
+  static REGEXP: RegExp =
+    /Recrawled this watch (\d+) times, most recently because:\n([^:]+)/;
+
+  root: string;
+  count: number;
+
+  constructor(root: string, count: number) {
     this.root = root;
     this.count = count;
   }
 
-  static findByRoot(root) {
+  static findByRoot(root: string): ?RecrawlWarning {
     for (let i = 0; i < this.RECRAWL_WARNINGS.length; i++) {
       const warning = this.RECRAWL_WARNINGS[i];
       if (warning.root === root) {
@@ -23,7 +40,7 @@ class RecrawlWarning {
     return undefined;
   }
 
-  static isRecrawlWarningDupe(warningMessage) {
+  static isRecrawlWarningDupe(warningMessage: mixed): boolean {
     if (typeof warningMessage !== 'string') {
       return false;
     }
@@ -52,9 +69,3 @@ class RecrawlWarning {
     }
   }
 }
-
-RecrawlWarning.RECRAWL_WARNINGS = [];
-RecrawlWarning.REGEXP =
-  /Recrawled this watch (\d+) times, most recently because:\n([^:]+)/;
-
-module.exports = RecrawlWarning;