From 05db979c0146f5848cd3d151c305b67684fd166e Mon Sep 17 00:00:00 2001
From: Colin Ihrig <cjihrig@gmail.com>
Date: Sun, 17 Mar 2024 00:17:36 -0400
Subject: [PATCH] test_runner: run top level tests in a microtask

This commit updates the test harness to prevent top level
tests from executing immediately. This allows certain config
data, such as filtering options, to be discovered before running
the tests.

PR-URL: https://github.com/nodejs/node/pull/52092
Reviewed-By: Moshe Atlow <moshe@atlow.co.il>
Reviewed-By: Chemi Atlow <chemi@atlow.co.il>
---
 lib/internal/test_runner/harness.js                 | 13 ++++++++++++-
 lib/internal/test_runner/runner.js                  |  1 +
 lib/internal/test_runner/test.js                    |  2 +-
 .../output/source_mapped_locations.snapshot         |  3 +++
 4 files changed, 17 insertions(+), 2 deletions(-)

diff --git a/lib/internal/test_runner/harness.js b/lib/internal/test_runner/harness.js
index b13ca112e5cc27..504cc1e93acd7a 100644
--- a/lib/internal/test_runner/harness.js
+++ b/lib/internal/test_runner/harness.js
@@ -25,6 +25,7 @@ const {
   setupTestReporters,
   shouldColorizeTestFiles,
 } = require('internal/test_runner/utils');
+const { queueMicrotask } = require('internal/process/task_queues');
 const { bigint: hrtime } = process.hrtime;
 
 const testResources = new SafeMap();
@@ -181,6 +182,7 @@ function setup(root) {
 
   root.harness = {
     __proto__: null,
+    allowTestsToRun: false,
     bootstrapComplete: false,
     coverage: FunctionPrototypeBind(collectCoverage, null, root, coverage),
     counters: {
@@ -219,7 +221,16 @@ function getGlobalRoot() {
 
 async function startSubtest(subtest) {
   await reportersSetup;
-  getGlobalRoot().harness.bootstrapComplete = true;
+
+  const root = getGlobalRoot();
+  if (!root.harness.bootstrapComplete) {
+    root.harness.bootstrapComplete = true;
+    queueMicrotask(() => {
+      root.harness.allowTestsToRun = true;
+      root.processPendingSubtests();
+    });
+  }
+
   await subtest.start();
 }
 
diff --git a/lib/internal/test_runner/runner.js b/lib/internal/test_runner/runner.js
index b7ac5756dad195..41fbfdab931392 100644
--- a/lib/internal/test_runner/runner.js
+++ b/lib/internal/test_runner/runner.js
@@ -538,6 +538,7 @@ function run(options = kEmptyObject) {
   }
   const runFiles = () => {
     root.harness.bootstrapComplete = true;
+    root.harness.allowTestsToRun = true;
     return SafePromiseAllSettledReturnVoid(testFiles, (path) => {
       const subtest = runTestFile(path, filesWatcher, opts);
       filesWatcher?.runningSubtests.set(path, subtest);
diff --git a/lib/internal/test_runner/test.js b/lib/internal/test_runner/test.js
index 126949d2584e38..daa3fa29c8d037 100644
--- a/lib/internal/test_runner/test.js
+++ b/lib/internal/test_runner/test.js
@@ -599,7 +599,7 @@ class Test extends AsyncResource {
     // it. Otherwise, return a Promise to the caller and mark the test as
     // pending for later execution.
     this.reporter.enqueue(this.nesting, this.loc, this.name);
-    if (!this.parent.hasConcurrency()) {
+    if (!this.root.harness.allowTestsToRun || !this.parent.hasConcurrency()) {
       const deferred = createDeferredPromise();
 
       deferred.test = this;
diff --git a/test/fixtures/test-runner/output/source_mapped_locations.snapshot b/test/fixtures/test-runner/output/source_mapped_locations.snapshot
index 24c3ee8d113446..29b70fd0d08378 100644
--- a/test/fixtures/test-runner/output/source_mapped_locations.snapshot
+++ b/test/fixtures/test-runner/output/source_mapped_locations.snapshot
@@ -21,6 +21,9 @@ not ok 1 - fails
     *
     *
     *
+    *
+    *
+    *
   ...
 1..1
 # tests 1