test_runner: skip --require for test orchestration process

lib/internal/main/test_runner.js

@@ -22,7 +22,7 @@ let debug = require('internal/util/debuglog').debuglog('test_runner', (fn) => {
   debug = fn;
 });
 
-prepareMainThreadExecution(false);
+prepareMainThreadExecution(false, true, false);
 markBootstrapComplete();
 
 let concurrency = getOptionValue('--test-concurrency') || true;

lib/internal/process/pre_execution.js

@@ -50,10 +50,11 @@ const {
   },
 } = require('internal/v8/startup_snapshot');
 
-function prepareMainThreadExecution(expandArgv1 = false, initializeModules = true) {
+function prepareMainThreadExecution(expandArgv1 = false, initializeModules = true, preloadModules = initializeModules) {
   return prepareExecution({
     expandArgv1,
     initializeModules,
+    preloadModules,
     isMainThread: true,
   });
 }
@@ -62,6 +63,7 @@ function prepareWorkerThreadExecution() {
   prepareExecution({
     expandArgv1: false,
     initializeModules: false,  // Will need to initialize it after policy setup
+    preloadModules: false,
     isMainThread: false,
   });
 }
@@ -95,7 +97,7 @@ function prepareShadowRealmExecution() {
 }
 
 function prepareExecution(options) {
-  const { expandArgv1, initializeModules, isMainThread } = options;
+  const { expandArgv1, initializeModules, isMainThread, preloadModules } = options;
 
   refreshRuntimeOptions();
   reconnectZeroFillToggle();
@@ -157,7 +159,7 @@ function prepareExecution(options) {
   }
 
   if (initializeModules) {
-    setupUserModules();
+    setupUserModules(false, preloadModules);
   }
 
   return mainEntry;
@@ -188,7 +190,7 @@ function setupSymbolDisposePolyfill() {
   }
 }
 
-function setupUserModules(forceDefaultLoader = false) {
+function setupUserModules(forceDefaultLoader = false, preloadModules = true) {
   initializeCJSLoader();
   initializeESMLoader(forceDefaultLoader);
   const {
@@ -203,7 +205,7 @@ function setupUserModules(forceDefaultLoader = false) {
   // Do not enable preload modules if custom loaders are disabled.
   // For example, loader workers are responsible for doing this themselves.
   // And preload modules are not supported in ShadowRealm as well.
-  if (!forceDefaultLoader) {
+  if (!forceDefaultLoader && preloadModules) {
     loadPreloadModules();
   }
   // Need to be done after --require setup.

test/fixtures/test-runner/print_pid.js

@@ -0,0 +1,3 @@
+'use strict';
+
+console.log({ pid: process.pid });

test/parallel/test-runner-cli.js

@@ -334,3 +334,29 @@ const testFixtures = fixtures.path('test-runner');
   assert.match(stdout, /# fail 0/);
   assert.match(stdout, /# skipped 0/);
 }
+
+{
+  // --require should only be applied to individual test processes, not the orchestrator
+  const args = ['--test', '--require', join(testFixtures, 'print_pid.js'),
+                join(testFixtures, 'index.js'), join(testFixtures, 'default-behavior', 'index.test.js')];
+  const child = spawnSync(process.execPath, args, { cwd: testFixtures });
+
+  assert.strictEqual(child.status, 1);
+  assert.strictEqual(child.signal, null);
+  assert.strictEqual(child.stderr.toString(), '');
+  assert.match(child.stdout.toString(), /pid: \d+/);
+  assert.doesNotMatch(child.stdout.toString(), new RegExp(`pid: ${child.pid}`));
+}
+
+{
+  // --import should only be applied to individual test processes, not the orchestrator
+  const args = ['--test', '--import', fixtures.fileURL('test-runner/print_pid.js'),
+                join(testFixtures, 'index.js'), join(testFixtures, 'default-behavior', 'index.test.js')];
+  const child = spawnSync(process.execPath, args, { cwd: testFixtures });
+
+  assert.strictEqual(child.status, 1);
+  assert.strictEqual(child.signal, null);
+  assert.strictEqual(child.stderr.toString(), '');
+  assert.match(child.stdout.toString(), /pid: \d+/);
+  assert.doesNotMatch(child.stdout.toString(), new RegExp(`pid: ${child.pid}`));
+}