test: test getWatcher$

Author: seanwu1105

python/tests/assets/watcher-test/change.txt

@@ -0,0 +1 @@
+original

src/test/suite/test-utils.ts

@@ -26,12 +26,12 @@ export async function sleep(ms = DEFAULT_TIMEOUT) {
   return new Promise(resolve => setTimeout(resolve, ms))
 }
 
-// TODO: This might not be necessary
 export async function setupE2EEnvironment() {
-  await sleep() // wait for extension to load Extension Gallery
-
-  const pythonExtension = extensions.getExtension('ms-python.python')
-  assert.ok(notNil(pythonExtension))
+  const pythonExtension = await waitFor(async () => {
+    const extension = extensions.getExtension('ms-python.python')
+    assert.ok(notNil(extension))
+    return extension
+  })
   if (!pythonExtension.isActive) await pythonExtension.activate()
 
   const extension = extensions.getExtension(`${publisher}.${name}`)

src/test/suite/watcher.test.ts

@@ -0,0 +1,89 @@
+import * as assert from 'node:assert'
+import * as path from 'node:path'
+import type { Subscription } from 'rxjs'
+import { workspace } from 'vscode'
+import { URI } from 'vscode-uri'
+import { getWatcher$ } from '../../watcher'
+import { TEST_ASSETS_PATH, waitFor } from './test-utils'
+
+suite('watcher', () => {
+  suite('getWatcher$', () => {
+    const test_folder = path.resolve(TEST_ASSETS_PATH, 'watcher-test')
+    const watcher$ = getWatcher$(`${test_folder}/**/*.txt`)
+
+    let subscription: Subscription
+    let results: URI[]
+
+    suite('when file is created', () => {
+      const filename = path.resolve(test_folder, 'create.txt')
+      const content = 'test'
+
+      setup(async () => {
+        results = []
+        await forceDeleteFile(filename)
+
+        subscription = watcher$.subscribe(v => results.push(v))
+        await workspace.fs.writeFile(URI.file(filename), Buffer.from(content))
+      })
+
+      teardown(async () => {
+        subscription.unsubscribe()
+        await forceDeleteFile(filename)
+      })
+
+      test('emits a value', async () =>
+        waitFor(async () => {
+          assert.ok(results[0])
+          const readResult = await workspace.fs.readFile(results[0])
+          assert.strictEqual(readResult.toString(), content)
+        }))
+    })
+
+    suite('when file is changed', () => {
+      const filename = path.resolve(test_folder, 'change.txt')
+      const newContent = getRandomString()
+
+      let originalContent: string
+
+      setup(async () => {
+        originalContent = (
+          await workspace.fs.readFile(URI.file(filename))
+        ).toString()
+        results = []
+        subscription = watcher$.subscribe(v => results.push(v))
+        await workspace.fs.writeFile(
+          URI.file(filename),
+          Buffer.from(newContent),
+        )
+      })
+
+      teardown(async () => {
+        subscription.unsubscribe()
+        await workspace.fs.writeFile(
+          URI.file(filename),
+          Buffer.from(originalContent),
+        )
+      })
+
+      test('emits a value', async () =>
+        waitFor(async () => {
+          assert.ok(results[0])
+          const readResult = await workspace.fs.readFile(results[0])
+          assert.strictEqual(readResult.toString(), newContent)
+        }))
+    })
+  })
+})
+
+async function forceDeleteFile(filename: string) {
+  try {
+    await workspace.fs.delete(URI.file(filename))
+  } catch {
+    // ignore error
+  }
+}
+
+function getRandomString() {
+  // eslint-disable-next-line @typescript-eslint/no-magic-numbers
+  return Math.random().toString(36).slice(2)
+}

src/watcher.ts

@@ -3,7 +3,6 @@ import type { GlobPattern } from 'vscode'
 import { Disposable, workspace } from 'vscode'
 import type { URI } from 'vscode-uri'
 
-// TODO: Unit test
 export function getWatcher$(globPattern: GlobPattern) {
   return defer(async () => workspace.createFileSystemWatcher(globPattern)).pipe(
     concatMap(watcher =>