test_runner: allow running test files in single process

lib/internal/main/test_runner.js

@@ -25,10 +25,12 @@ let debug = require('internal/util/debuglog').debuglog('test_runner', (fn) => {
 prepareMainThreadExecution(false);
 markBootstrapComplete();
 
+
+const isolation = getOptionValue('--experimental-test-isolation');
 let concurrency = getOptionValue('--test-concurrency') || true;
 let inspectPort;
 
-if (isUsingInspector()) {
+if (isUsingInspector() && isolation !== 'none') {
   process.emitWarning('Using the inspector with --test forces running at a concurrency of 1. ' +
   'Use the inspectPort option to run with concurrency');
   concurrency = 1;
@@ -65,6 +67,7 @@ const timeout = getOptionValue('--test-timeout') || Infinity;
 const options = {
   concurrency,
   inspectPort,
+  isolation,
   watch: getOptionValue('--watch'),
   setup: setupTestReporters,
   timeout,

lib/internal/test_runner/harness.js

@@ -214,7 +214,7 @@ function getGlobalRoot() {
 
 async function startSubtest(subtest) {
   await reportersSetup;
-  getGlobalRoot().harness.bootstrapComplete = true;
+  subtest.root.harness.bootstrapComplete = true;
   await subtest.start();
 }
 

lib/internal/test_runner/runner.js

@@ -29,7 +29,8 @@ const {
 
 const { spawn } = require('child_process');
 const { finished } = require('internal/streams/end-of-stream');
-const { resolve } = require('path');
+const { resolve, isAbsolute } = require('path');
+const { pathToFileURL } = require('internal/url');
 const { DefaultDeserializer, DefaultSerializer } = require('v8');
 // TODO(aduh95): switch to internal/readline/interface when backporting to Node.js 16.x is no longer a concern.
 const { createInterface } = require('readline');
@@ -50,6 +51,7 @@ const {
   validateBoolean,
   validateFunction,
   validateObject,
+  validateOneOf,
   validateInteger,
 } = require('internal/validators');
 const { getInspectPort, isUsingInspector, isInspectorMessage } = require('internal/util/inspector');
@@ -64,6 +66,7 @@ const {
   kTestCodeFailure,
   kTestTimeoutFailure,
   Test,
+  Suite,
 } = require('internal/test_runner/test');
 
 const {
@@ -134,7 +137,34 @@ const v8Header = serializer.releaseBuffer();
 const kV8HeaderLength = TypedArrayPrototypeGetLength(v8Header);
 const kSerializedSizeHeader = 4 + kV8HeaderLength;
 
-class FileTest extends Test {
+
+class InProcessFileTest extends Suite {
+  constructor(options) {
+    super(options);
+    this.loc ??= {
+      __proto__: null,
+      line: 1,
+      column: 1,
+      file: resolve(this.name),
+    };
+    this.nesting = -1;
+    this.reportedType = 'test';
+  }
+
+  #reported = false;
+  reportStarted() {}
+  report() {
+    const skipReporting = this.subtests.length > 0;
+    if (!skipReporting && !this.#reported) {
+      this.nesting = 0;
+      this.#reported = true;
+      super.reportStarted();
+      super.report();
+    }
+  }
+}
+
+class SpawnFileTest extends Test {
   // This class maintains two buffers:
   #reportBuffer = []; // Parsed items waiting for this.isClearToSend()
   #rawBuffer = []; // Raw data waiting to be parsed
@@ -319,7 +349,21 @@ class FileTest extends Test {
 
 function runTestFile(path, filesWatcher, opts) {
   const watchMode = filesWatcher != null;
-  const subtest = opts.root.createSubtest(FileTest, path, { __proto__: null, signal: opts.signal }, async (t) => {
+  const Factory = opts.isolation === 'none' ? InProcessFileTest : SpawnFileTest;
+  const subtest = opts.root.createSubtest(Factory, path, { __proto__: null, signal: opts.signal }, async (t) => {
+    if (opts.isolation === 'none') {
+      let parentURL;
+      try {
+        parentURL = pathToFileURL(process.cwd() + '/').href;
+      } catch {
+        parentURL = 'file:///';
+      }
+
+      const { esmLoader } = require('internal/process/esm_loader');
+
+      await esmLoader.import(isAbsolute(path) ? path : `./${path}`, parentURL, { __proto__: null });
+      return;
+    }
     const args = getRunArgs(path, opts);
     const stdio = ['pipe', 'pipe', 'pipe'];
     const env = { __proto__: null, ...process.env, NODE_TEST_CONTEXT: 'child-v8' };
@@ -439,7 +483,7 @@ function watchFiles(testFiles, opts) {
 function run(options = kEmptyObject) {
   validateObject(options, 'options');
 
-  let { testNamePatterns, shard } = options;
+  let { testNamePatterns, shard, isolation } = options;
   const { concurrency, timeout, signal, files, inspectPort, watch, setup, only } = options;
 
   if (files != null) {
@@ -470,6 +514,10 @@ function run(options = kEmptyObject) {
   if (setup != null) {
     validateFunction(setup, 'options.setup');
   }
+  isolation ||= 'process';
+  if (isolation != null) {
+    validateOneOf(isolation, 'options.isolation', ['process', 'none']);
+  }
   if (testNamePatterns != null) {
     if (!ArrayIsArray(testNamePatterns)) {
       testNamePatterns = [testNamePatterns];
@@ -501,7 +549,7 @@ function run(options = kEmptyObject) {
 
   let postRun = () => root.postRun();
   let filesWatcher;
-  const opts = { __proto__: null, root, signal, inspectPort, testNamePatterns, only };
+  const opts = { __proto__: null, root, signal, inspectPort, testNamePatterns, only, isolation };
   if (watch) {
     filesWatcher = watchFiles(testFiles, opts);
     postRun = undefined;
@@ -521,6 +569,6 @@ function run(options = kEmptyObject) {
 }
 
 module.exports = {
-  FileTest, // Exported for tests only
+  SpawnFileTest, // Exported for tests only
   run,
 };

lib/internal/test_runner/test.js

@@ -70,7 +70,6 @@ const kHookFailure = 'hookFailed';
 const kDefaultTimeout = null;
 const noop = FunctionPrototype;
 const kShouldAbort = Symbol('kShouldAbort');
-const kFilename = process.argv?.[1];
 const kHookNames = ObjectSeal(['before', 'after', 'beforeEach', 'afterEach']);
 const kUnwrapErrors = new SafeSet()
   .add(kTestCodeFailure).add(kHookFailure)
@@ -349,7 +348,7 @@ class Test extends AsyncResource {
       this.diagnostic(warning);
     }
 
-    if (loc === undefined || kFilename === undefined) {
+    if (loc === undefined) {
       this.loc = undefined;
     } else {
       this.loc = {
@@ -826,11 +825,13 @@ class Test extends AsyncResource {
       details.type = this.reportedType;
     }
 
+    const isTopLevel = this.nesting === 0;
+    const testNumber = isTopLevel ? this.root.harness.counters.topLevel : this.testNumber;
     if (this.passed) {
-      this.reporter.ok(this.nesting, this.loc, this.testNumber, this.name, details, directive);
+      this.reporter.ok(this.nesting, this.loc, testNumber, this.name, details, directive);
     } else {
       details.error = this.error;
-      this.reporter.fail(this.nesting, this.loc, this.testNumber, this.name, details, directive);
+      this.reporter.fail(this.nesting, this.loc, testNumber, this.name, details, directive);
     }
 
     for (let i = 0; i < this.diagnostics.length; i++) {

src/env-inl.h

@@ -661,7 +661,8 @@ inline bool Environment::owns_inspector() const {
 
 inline bool Environment::should_create_inspector() const {
   return (flags_ & EnvironmentFlags::kNoCreateInspector) == 0 &&
-         !options_->test_runner && !options_->watch_mode;
+         (!options_->test_runner || options_->test_isolation == "none") &&
+         !options_->watch_mode;
 }
 
 inline bool Environment::tracks_unmanaged_fds() const {

src/node_options.cc

@@ -166,9 +166,10 @@ void EnvironmentOptions::CheckOptions(std::vector<std::string>* errors,
           "--watch-path cannot be used in combination with --test");
     }
 
-#ifndef ALLOW_ATTACHING_DEBUGGER_IN_TEST_RUNNER
-    debug_options_.allow_attaching_debugger = false;
-#endif
+    if (watch_mode && test_isolation == "none") {
+      errors->push_back(
+          "--watch cannot be used with --experimental-test-isolation=none");
+    }
   }
 
   if (watch_mode) {
@@ -641,6 +642,10 @@ EnvironmentOptionsParser::EnvironmentOptionsParser() {
             "run test at specific shard",
             &EnvironmentOptions::test_shard,
             kAllowedInEnvvar);
+  AddOption("--experimental-test-isolation",
+            "isolation mode of test runner",
+            &EnvironmentOptions::test_isolation,
+            kAllowedInEnvvar);
   AddOption("--test-udp-no-try-send", "",  // For testing only.
             &EnvironmentOptions::test_udp_no_try_send);
   AddOption("--throw-deprecation",

src/node_options.h

@@ -172,6 +172,7 @@ class EnvironmentOptions : public Options {
   bool test_only = false;
   bool test_udp_no_try_send = false;
   std::string test_shard;
+  std::string test_isolation;
   bool throw_deprecation = false;
   bool trace_atomics_wait = false;
   bool trace_deprecation = false;

test/parallel/test-runner-v8-deserializer.mjs

@@ -26,7 +26,7 @@ describe('v8 deserializer', () => {
   let reported;
   beforeEach(() => {
     reported = [];
-    fileTest = new runner.FileTest({ name: 'filetest' });
+    fileTest = new runner.SpawnFileTest({ name: 'filetest' });
     fileTest.reporter.on('data', (data) => reported.push(data));
     assert(fileTest.isClearToSend());
   });