fix: improve open handles detection

e2e/__tests__/__snapshots__/detectOpenHandles.ts.snap

@@ -9,7 +9,7 @@ This usually means that there are asynchronous operations that weren't stopped i
 `;
 
 exports[`prints out info about open handlers 1`] = `
-Jest has detected the following 1 open handle potentially keeping Jest from exiting:
+Jest has detected the following 1 open handle potentially preventing Jest from exiting:
 
   ●  GETADDRINFOREQWRAP
 
@@ -24,7 +24,7 @@ Jest has detected the following 1 open handle potentially keeping Jest from exit
 `;
 
 exports[`prints out info about open handlers from inside tests 1`] = `
-Jest has detected the following 1 open handle potentially keeping Jest from exiting:
+Jest has detected the following 1 open handle potentially preventing Jest from exiting:
 
   ●  Timeout
 

packages/jest-core/src/cli/index.ts

@@ -102,7 +102,7 @@ export async function runCLI(
 
     const message =
       chalk.red(
-        `\nJest has detected the following ${openHandlesString} potentially keeping Jest from exiting:\n\n`,
+        `\nJest has detected the following ${openHandlesString} potentially preventing Jest from exiting:\n\n`,
       ) + formatted.join('\n\n');
 
     console.error(message);

packages/jest-core/src/collectHandles.ts

@@ -11,28 +11,6 @@ import {formatExecError} from 'jest-message-util';
 import {ErrorWithStack} from 'jest-util';
 import stripAnsi = require('strip-ansi');
 
-function stackIsFromUser(stack: string) {
-  // Either the test file, or something required by it
-  if (stack.includes('Runtime.requireModule')) {
-    return true;
-  }
-
-  // jest-jasmine it or describe call
-  if (stack.includes('asyncJestTest') || stack.includes('asyncJestLifecycle')) {
-    return true;
-  }
-
-  // An async function call from within circus
-  if (stack.includes('callAsyncCircusFn')) {
-    // jest-circus it or describe call
-    return (
-      stack.includes('_callCircusTest') || stack.includes('_callCircusHook')
-    );
-  }
-
-  return false;
-}
-
 const alwaysActive = () => true;
 
 // Inspired by https://github.com/mafintosh/why-is-node-running/blob/master/index.js
@@ -57,7 +35,7 @@ export default function collectHandles(): () => Array<Error> {
       }
       const error = new ErrorWithStack(type, initHook);
 
-      if (stackIsFromUser(error.stack || '')) {
+      if ((error.stack || '').trim().length > 0) {
         let isActive: () => boolean;
 
         if (type === 'Timeout' || type === 'Immediate') {
@@ -125,5 +103,7 @@ export function formatHandleErrors(
 
         return true;
       })
+      // only keep stacks with at least one frame. `length === 1` means just the heading (normally meaning node internal), which is useless
+      .filter(stack => stack.trim().split('\n').length > 1)
   );
 }

packages/jest-core/src/runJest.ts

@@ -260,6 +260,11 @@ export default async function runJest({
     await runGlobalHook({allTests, globalConfig, moduleName: 'globalTeardown'});
   }
 
+  if (collectHandles) {
+    // wait 100ms to allow some handles to be cleaned up, including Jest's internal timeouts
+    await new Promise(resolve => setTimeout(resolve, 100));
+  }
+
   await processResults(results, {
     collectHandles,
     json: globalConfig.json,

packages/jest-message-util/src/index.ts

@@ -23,10 +23,23 @@ type Path = Config.Path;
 // stack utils tries to create pretty stack by making paths relative.
 const stackUtils = new StackUtils({cwd: 'something which does not exist'});
 
-let nodeInternals: Array<RegExp> = [];
+let nodeInternals: ReadonlyArray<RegExp> = [];
 
 try {
-  nodeInternals = StackUtils.nodeInternals();
+  // `reduce` is workaround for https://github.com/tapjs/stack-utils/issues/48
+  nodeInternals = StackUtils.nodeInternals().reduce<Array<RegExp>>(
+    (internals, internal) => {
+      const sourceWithoutParens = internal.source
+        // remove leading and trailing parens (which are escaped) and the $
+        .slice(2, internal.source.length - 3);
+
+      return internals.concat(
+        internal,
+        new RegExp(`at ${sourceWithoutParens}$`),
+      );
+    },
+    [],
+  );
 } catch (e) {
   // `StackUtils.nodeInternals()` fails in browsers. We don't need to remove
   // node internals in the browser though, so no issue.