chore: import upstream snapshot with attribution

2026-07-13 13:34:48 +08:00
commit 77bb5bf71f
3762 changed files with 353249 additions and 0 deletions
@@ -0,0 +1,61 @@
+import type watcher from '@parcel/watcher'
+import { debounceAsync } from './concurrency-utils'
+import { EventEmitter } from './event-emitter'
+
+export type FileChangeHandler = (events: watcher.Event[]) => Promise<void>
+
+type EmptyObject = Record<never, never>
+type FileWatcherEvent = {
+  error: unknown
+  close: EmptyObject
+}
+
+type FileWatcherOptions = watcher.Options & {
+  debounceMs?: number
+}
+
+/**
+ * Wraps the Parcel file watcher to ensure errors can be catched in an async/await fashion
+ */
+export class FileWatcher {
+  public static async watch(dir: string, fn: FileChangeHandler, opt?: FileWatcherOptions) {
+    const eventEmitter = new EventEmitter<FileWatcherEvent>()
+
+    let subscriptionHandler = async (err: Error | null, events: watcher.Event[]) => {
+      if (err) {
+        eventEmitter.emit('error', err)
+        return
+      }
+
+      try {
+        await fn(events)
+      } catch (thrown) {
+        eventEmitter.emit('error', thrown)
+      }
+    }
+
+    if (opt?.debounceMs) {
+      subscriptionHandler = debounceAsync(subscriptionHandler, opt.debounceMs)
+    }
+    const watcher = await import('@parcel/watcher')
+
+    const subscription = await watcher.subscribe(dir, subscriptionHandler, opt)
+    return new FileWatcher(subscription, eventEmitter)
+  }
+
+  private constructor(
+    private _subscription: watcher.AsyncSubscription,
+    private _errorEmitter: EventEmitter<FileWatcherEvent>
+  ) {}
+
+  public async close() {
+    await this._subscription.unsubscribe()
+    this._errorEmitter.emit('close', {})
+  }
+
+  public wait = () =>
+    new Promise((resolve, reject) => {
+      this._errorEmitter.once('error', reject)
+      this._errorEmitter.once('close', resolve)
+    })
+}