test_runner: run global after() hook earlier

This commit moves the global after() hook execution from the
'beforeExit' event to the point where all tests have finished
running. This gives the global after() a chance to clean up
handles that would otherwise prevent the 'beforeExit' event
from being emitted.

Fixes: #49056

lib/internal/test_runner/harness.js

@@ -142,7 +142,7 @@ function setup(root) {
     createProcessEventHandler('unhandledRejection', root);
   const coverage = configureCoverage(root, globalOptions);
   const exitHandler = async () => {
-    await root.run(new ERR_TEST_FAILURE(
+    root.postRun(new ERR_TEST_FAILURE(
       'Promise resolution is still pending but the event loop has already resolved',
       kCancelledByParent));
 

lib/internal/test_runner/test.js

@@ -643,9 +643,16 @@ class Test extends AsyncResource {
       }
     }
 
-    // Clean up the test. Then, try to report the results and execute any
-    // tests that were pending due to available concurrency.
-    this.postRun(pendingSubtestsError);
+    if (this.parent !== null) {
+      // Clean up the test. Then, try to report the results and execute any
+      // tests that were pending due to available concurrency.
+      //
+      // The root test is skipped here because it is a special case. Its
+      // postRun() method is called when the process is getting ready to exit.
+      // This helps catch any asynchronous activity that occurs after the tests
+      // have finished executing.
+      this.postRun(pendingSubtestsError);
+    }
   }
 
   postRun(pendingSubtestsError) {
@@ -687,6 +694,18 @@ class Test extends AsyncResource {
       this.parent.addReadySubtest(this);
       this.parent.processReadySubtestRange(false);
       this.parent.processPendingSubtests();
+
+      if (this.parent === this.root &&
+          this.root.activeSubtests === 0 &&
+          this.root.pendingSubtests.length === 0 &&
+          this.root.readySubtests.size === 0 &&
+          this.root.hooks.after.length > 0) {
+        // This is done so that any global after() hooks are run. At this point
+        // all of the tests have finished running. However, there might be
+        // ref'ed handles keeping the event loop alive. This gives the global
+        // after() hook a chance to clean them up.
+        this.root.run();
+      }
     } else if (!this.reported) {
       if (!this.passed && failed === 0 && this.error) {
         this.reporter.fail(0, kFilename, this.subtests.length + 1, kFilename, {

test/fixtures/test-runner/output/global_after_should_fail_the_test.snapshot

@@ -21,7 +21,6 @@ not ok 2 - /test/fixtures/test-runner/output/global_after_should_fail_the_test.j
     *
     *
     *
-    *
   ...
 1..1
 # tests 1