test_runner: support 'only' tests

This commit introduces a CLI flag and test runner functionality
to support running a subset of tests that are indicated by an
'only' option passed to the test.

PR-URL: https://github.com/nodejs/node/pull/42514
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Antoine du Hamel <duhamelantoine1995@gmail.com>

1 files changed, 23 insertions, 10 deletions

diff --git a/lib/internal/test_runner/test.js b/lib/internal/test_runner/test.js
index e2dddf5cc20..3e632cc1c52 100644
--- a/lib/internal/test_runner/test.js
+++ b/lib/internal/test_runner/test.js
@@ -13,6 +13,7 @@ const {
     ERR_TEST_FAILURE,
   },
 } = require('internal/errors');
+const { getOptionValue } = require('internal/options');
 const { TapStream } = require('internal/test_runner/tap_stream');
 const { createDeferredPromise } = require('internal/util');
 const { isPromise } = require('internal/util/types');
@@ -26,6 +27,7 @@ const kSubtestsFailed = 'subtestsFailed';
 const kTestCodeFailure = 'testCodeFailure';
 const kDefaultIndent = '    ';
 const noop = FunctionPrototype;
+const testOnlyFlag = getOptionValue('--test-only');
 
 class TestContext {
   #test;
@@ -38,6 +40,10 @@ class TestContext {
     this.#test.diagnostic(message);
   }
 
+  runOnly(value) {
+    this.#test.runOnlySubtests = !!value;
+  }
+
   skip(message) {
     this.#test.skip(message);
   }
@@ -57,8 +63,8 @@ class Test extends AsyncResource {
   constructor(options) {
     super('Test');
 
-    let { fn, name, parent } = options;
-    const { concurrency, skip, todo } = options;
+    let { fn, name, parent, skip } = options;
+    const { concurrency, only, todo } = options;
 
     if (typeof fn !== 'function') {
       fn = noop;
@@ -72,19 +78,13 @@ class Test extends AsyncResource {
       parent = null;
     }
 
-    if (skip) {
-      fn = noop;
-    }
-
-    this.fn = fn;
-    this.name = name;
-    this.parent = parent;
-
     if (parent === null) {
       this.concurrency = 1;
       this.indent = '';
       this.indentString = kDefaultIndent;
+      this.only = testOnlyFlag;
       this.reporter = new TapStream();
+      this.runOnlySubtests = this.only;
       this.testNumber = 0;
     } else {
       const indent = parent.parent === null ? parent.indent :
@@ -93,7 +93,9 @@ class Test extends AsyncResource {
       this.concurrency = parent.concurrency;
       this.indent = indent;
       this.indentString = parent.indentString;
+      this.only = only ?? !parent.runOnlySubtests;
       this.reporter = parent.reporter;
+      this.runOnlySubtests = !this.only;
       this.testNumber = parent.subtests.length + 1;
     }
 
@@ -101,6 +103,17 @@ class Test extends AsyncResource {
       this.concurrency = concurrency;
     }
 
+    if (testOnlyFlag && !this.only) {
+      skip = '\'only\' option not set';
+    }
+
+    if (skip) {
+      fn = noop;
+    }
+
+    this.fn = fn;
+    this.name = name;
+    this.parent = parent;
     this.cancelled = false;
     this.skipped = !!skip;
     this.isTodo = !!todo;