From ae3b43c935383ef2f06ae3ad18a3e155e70a18e4 Mon Sep 17 00:00:00 2001
From: Simen Bekkhus <sbekkhus91@gmail.com>
Date: Tue, 28 Jul 2020 10:44:21 +0200
Subject: [PATCH] chore: make TestWatcher extend emittery

---
 packages/jest-core/package.json       | 1 +
 packages/jest-core/src/TestWatcher.ts | 4 ++--
 packages/jest-runner/package.json     | 1 +
 packages/jest-runner/src/index.ts     | 3 +--
 packages/jest-runner/src/types.ts     | 8 +++-----
 yarn.lock                             | 9 +++++++++
 6 files changed, 17 insertions(+), 9 deletions(-)

diff --git a/packages/jest-core/package.json b/packages/jest-core/package.json
index 862d3c54995a..7fa80ffaffb5 100644
--- a/packages/jest-core/package.json
+++ b/packages/jest-core/package.json
@@ -13,6 +13,7 @@
     "@types/node": "*",
     "ansi-escapes": "^4.2.1",
     "chalk": "^4.0.0",
+    "emittery": "^0.7.1",
     "exit": "^0.1.2",
     "graceful-fs": "^4.2.4",
     "jest-changed-files": "^26.1.0",
diff --git a/packages/jest-core/src/TestWatcher.ts b/packages/jest-core/src/TestWatcher.ts
index 750dcbe45efc..651c78f122eb 100644
--- a/packages/jest-core/src/TestWatcher.ts
+++ b/packages/jest-core/src/TestWatcher.ts
@@ -5,13 +5,13 @@
  * LICENSE file in the root directory of this source tree.
  */
 
-import {EventEmitter} from 'events';
+import emittery = require('emittery');
 
 type State = {
   interrupted: boolean;
 };
 
-export default class TestWatcher extends EventEmitter {
+export default class TestWatcher extends emittery.Typed<{change: State}> {
   state: State;
   private _isWatchMode: boolean;
 
diff --git a/packages/jest-runner/package.json b/packages/jest-runner/package.json
index 9a1b9cf755dc..fe352d571939 100644
--- a/packages/jest-runner/package.json
+++ b/packages/jest-runner/package.json
@@ -16,6 +16,7 @@
     "@jest/types": "^26.1.0",
     "@types/node": "*",
     "chalk": "^4.0.0",
+    "emittery": "^0.7.1",
     "exit": "^0.1.2",
     "graceful-fs": "^4.2.4",
     "jest-config": "^26.1.0",
diff --git a/packages/jest-runner/src/index.ts b/packages/jest-runner/src/index.ts
index 0f1d069c6af0..485d9fe3ebe8 100644
--- a/packages/jest-runner/src/index.ts
+++ b/packages/jest-runner/src/index.ts
@@ -21,7 +21,6 @@ import type {
   TestRunnerContext as JestTestRunnerContext,
   TestRunnerOptions as JestTestRunnerOptions,
   TestWatcher as JestTestWatcher,
-  WatcherState,
 } from './types';
 
 const TEST_WORKER_PATH = require.resolve('./testWorker');
@@ -179,7 +178,7 @@ class TestRunner {
     };
 
     const onInterrupt = new Promise((_, reject) => {
-      watcher.on('change', (state: WatcherState) => {
+      watcher.on('change', state => {
         if (state.interrupted) {
           reject(new CancelRun());
         }
diff --git a/packages/jest-runner/src/types.ts b/packages/jest-runner/src/types.ts
index 69d9525ff73c..868d0980c2ca 100644
--- a/packages/jest-runner/src/types.ts
+++ b/packages/jest-runner/src/types.ts
@@ -5,7 +5,7 @@
  * LICENSE file in the root directory of this source tree.
  */
 
-import type {EventEmitter} from 'events';
+import type {Typed as EmitteryTyped} from 'emittery';
 import type {Config} from '@jest/types';
 import type {SerializableError, TestResult} from '@jest/test-result';
 import type {JestEnvironment} from '@jest/environment';
@@ -61,10 +61,8 @@ export type TestRunnerSerializedContext = {
 };
 
 // TODO: Should live in `@jest/core` or `jest-watcher`
-export type WatcherState = {
-  interrupted: boolean;
-};
-export interface TestWatcher extends EventEmitter {
+type WatcherState = {interrupted: boolean};
+export interface TestWatcher extends EmitteryTyped<{change: WatcherState}> {
   state: WatcherState;
   setState(state: WatcherState): void;
   isInterrupted(): boolean;
diff --git a/yarn.lock b/yarn.lock
index 4569c6275937..4aeb2b45a6ed 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -1708,6 +1708,7 @@ __metadata:
     "@types/rimraf": ^3.0.0
     ansi-escapes: ^4.2.1
     chalk: ^4.0.0
+    emittery: ^0.7.1
     exit: ^0.1.2
     graceful-fs: ^4.2.4
     jest-changed-files: ^26.1.0
@@ -7224,6 +7225,13 @@ __metadata:
   languageName: node
   linkType: hard
 
+"emittery@npm:^0.7.1":
+  version: 0.7.1
+  resolution: "emittery@npm:0.7.1"
+  checksum: 917b0995126e004ddf175e7d0a74ae8608083846c3f3608e964bf13caba220a003b7455ced5bf813a40e977605be48e53c74f6150fbe587a47ef6b985b8a447e
+  languageName: node
+  linkType: hard
+
 "emoji-regex@npm:>=6.0.0 <=6.1.1":
   version: 6.1.1
   resolution: "emoji-regex@npm:6.1.1"
@@ -11453,6 +11461,7 @@ fsevents@^1.2.7:
     "@types/node": "*"
     "@types/source-map-support": ^0.5.0
     chalk: ^4.0.0
+    emittery: ^0.7.1
     exit: ^0.1.2
     graceful-fs: ^4.2.4
     jest-circus: ^26.1.0