fix: don't report promises as open handles (#6716)

CHANGELOG.md

@@ -12,6 +12,7 @@
 - `[jest-config]` Fix `--coverage` with `--findRelatedTests` overwriting `collectCoverageFrom` options ([#6736](https://github.com/facebook/jest/pull/6736))
 - `[jest-config]` Update default config for testURL from 'about:blank' to 'http://localhost' to address latest JSDOM security warning. ([#6792](https://github.com/facebook/jest/pull/6792))
 - `[jest-cli]` Fix `testMatch` not working with negations ([#6648](https://github.com/facebook/jest/pull/6648))
+- `[jest-cli]` Don't report promises as open handles ([#6716](https://github.com/facebook/jest/pull/6716))
 
 ## 23.4.2
 

e2e/__tests__/detect_open_handles.js

@@ -25,13 +25,13 @@ try {
 }
 
 function getTextAfterTest(stderr) {
-  return stderr.split('Ran all test suites.')[1].trim();
+  return (stderr.split(/Ran all test suites(.*)\n/)[2] || '').trim();
 }
 
 it('prints message about flag on slow tests', async () => {
   const {stderr} = await runJest.until(
     'detect-open-handles',
-    [],
+    ['outside'],
     'Jest did not exit one second after the test run has completed.',
   );
   const textAfterTest = getTextAfterTest(stderr);
@@ -42,7 +42,7 @@ it('prints message about flag on slow tests', async () => {
 it('prints message about flag on forceExit', async () => {
   const {stderr} = await runJest.until(
     'detect-open-handles',
-    ['--forceExit'],
+    ['outside', '--forceExit'],
     'Force exiting Jest',
   );
   const textAfterTest = getTextAfterTest(stderr);
@@ -53,7 +53,7 @@ it('prints message about flag on forceExit', async () => {
 it('prints out info about open handlers', async () => {
   const {stderr} = await runJest.until(
     'detect-open-handles',
-    ['--detectOpenHandles'],
+    ['outside', '--detectOpenHandles'],
     'Jest has detected',
   );
   const textAfterTest = getTextAfterTest(stderr);
@@ -70,7 +70,18 @@ it('prints out info about open handlers', async () => {
       8 | 
 
       at Object.<anonymous> (server.js:7:5)
-      at Object.<anonymous> (__tests__/test.js:1:1)
+      at Object.<anonymous> (__tests__/outside.js:1:1)
 `.trim(),
   );
 });
+
+it('does not report promises', () => {
+  // The test here is basically that it exits cleanly without reporting anything (does not need `runJest.until`)
+  const {stderr} = runJest('detect-open-handles', [
+    'promise',
+    '--detectOpenHandles',
+  ]);
+  const textAfterTest = getTextAfterTest(stderr);
+
+  expect(textAfterTest).toBe('');
+});

e2e/detect-open-handles/__tests__/promise.js

@@ -0,0 +1,4 @@
+test('something', () => {
+  new Promise(() => {});
+  expect(true).toBe(true);
+});

packages/jest-cli/src/collectHandles.js

@@ -17,6 +17,9 @@ export default function collectHandles(): () => Array<Error> {
   const activeHandles: Map<string, Error> = new Map();
 
   function initHook(asyncId, type) {
+    if (type === 'PROMISE') {
+      return;
+    }
     const error = new Error(type);
 
     if (Error.captureStackTrace) {