From 6584d5f811f2124af08205e934ff16dfef3d44f0 Mon Sep 17 00:00:00 2001
From: Marco Ippolito <marcoippolito54@gmail.com>
Date: Wed, 11 Jun 2025 12:12:04 +0200
Subject: [PATCH] module: remove experimental warning from type stripping
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PR-URL: https://github.com/nodejs/node/pull/58643
Refs: https://github.com/nodejs/typescript/issues/24
Reviewed-By: Jacob Smith <jacob@frende.me>
Reviewed-By: Michaël Zasso <targos@protonmail.com>
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: Jordan Harband <ljharb@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Filip Skokan <panva.ip@gmail.com>
Reviewed-By: Ethan Arrowood <ethan@arrowood.dev>
Reviewed-By: Trivikram Kamat <trivikr.dev@gmail.com>
Reviewed-By: Chengzhong Wu <legendecas@gmail.com>
Reviewed-By: Chemi Atlow <chemi@atlow.co.il>
---
 doc/api/typescript.md                     |  3 +++
 lib/internal/modules/typescript.js        |  9 +++------
 lib/internal/process/execution.js         |  9 ++-------
 test/es-module/test-typescript-eval.mjs   | 10 +++++-----
 test/es-module/test-typescript-module.mjs |  2 +-
 test/es-module/test-typescript.mjs        | 13 ++++++++++++-
 6 files changed, 26 insertions(+), 20 deletions(-)

diff --git a/doc/api/typescript.md b/doc/api/typescript.md
index ff111dc6885..66f95d6b878 100644
--- a/doc/api/typescript.md
+++ b/doc/api/typescript.md
@@ -2,6 +2,9 @@
 
 <!-- YAML
 changes:
+  - version: REPLACEME
+    pr-url: https://github.com/nodejs/node/pull/58643
+    description: Type stripping no longer emits an experimental warning.
   - version: v23.6.0
     pr-url: https://github.com/nodejs/node/pull/56350
     description: Type stripping is enabled by default.
diff --git a/lib/internal/modules/typescript.js b/lib/internal/modules/typescript.js
index a7731772c35..fe029c7cd24 100644
--- a/lib/internal/modules/typescript.js
+++ b/lib/internal/modules/typescript.js
@@ -33,7 +33,8 @@ const {
  * @type {string}
  */
 const getTypeScriptParsingMode = getLazy(() =>
-  (getOptionValue('--experimental-transform-types') ? 'transform' : 'strip-only'),
+  (getOptionValue('--experimental-transform-types') ?
+    (emitExperimentalWarning('Transform Types'), 'transform') : 'strip-only'),
 );
 
 /**
@@ -174,13 +175,9 @@ function getCachedCodeType(mode, sourceMap) {
  * It is used by internal loaders.
  * @param {string} source TypeScript code to parse.
  * @param {string} filename The filename of the source code.
- * @param {boolean} emitWarning Whether to emit a warning.
  * @returns {TransformOutput} The stripped TypeScript code.
  */
-function stripTypeScriptModuleTypes(source, filename, emitWarning = true) {
-  if (emitWarning) {
-    emitExperimentalWarning('Type Stripping');
-  }
+function stripTypeScriptModuleTypes(source, filename) {
   assert(typeof source === 'string');
   if (isUnderNodeModules(filename)) {
     throw new ERR_UNSUPPORTED_NODE_MODULES_TYPE_STRIPPING(filename);
diff --git a/lib/internal/process/execution.js b/lib/internal/process/execution.js
index 9ca9a13a6bd..fc5f7d09ac3 100644
--- a/lib/internal/process/execution.js
+++ b/lib/internal/process/execution.js
@@ -39,7 +39,6 @@ const { getOptionValue } = require('internal/options');
 const {
   makeContextifyScript, runScriptInThisContext,
 } = require('internal/vm');
-const { emitExperimentalWarning } = require('internal/util');
 // shouldAbortOnUncaughtToggle is a typed array for faster
 // communication with JS.
 const { shouldAbortOnUncaughtToggle } = internalBinding('util');
@@ -261,7 +260,7 @@ function evalTypeScript(name, source, breakFirstLine, print, shouldLoadESM = fal
     compiledScript = compileScript(name, source, baseUrl);
   } catch (originalError) {
     try {
-      sourceToRun = stripTypeScriptModuleTypes(source, kEvalTag, false);
+      sourceToRun = stripTypeScriptModuleTypes(source, kEvalTag);
       // Retry the CJS/ESM syntax detection after stripping the types.
       if (shouldUseModuleEntryPoint(name, sourceToRun)) {
         return evalTypeScriptModuleEntryPoint(source, print);
@@ -269,8 +268,6 @@ function evalTypeScript(name, source, breakFirstLine, print, shouldLoadESM = fal
       // If the ContextifiedScript was successfully created, execute it.
       // outside the try-catch block to avoid catching runtime errors.
       compiledScript = compileScript(name, sourceToRun, baseUrl);
-      // Emit the experimental warning after the code was successfully evaluated.
-      emitExperimentalWarning('Type Stripping');
     } catch (tsError) {
       // If it's invalid or unsupported TypeScript syntax, rethrow the original error
       // with the TypeScript error message added to the stack.
@@ -324,12 +321,10 @@ function evalTypeScriptModuleEntryPoint(source, print) {
         moduleWrap = loader.createModuleWrap(source, url);
       } catch (originalError) {
         try {
-          const strippedSource = stripTypeScriptModuleTypes(source, kEvalTag, false);
+          const strippedSource = stripTypeScriptModuleTypes(source, kEvalTag);
           // If the moduleWrap was successfully created, execute the module job.
           // outside the try-catch block to avoid catching runtime errors.
           moduleWrap = loader.createModuleWrap(strippedSource, url);
-          // Emit the experimental warning after the code was successfully compiled.
-          emitExperimentalWarning('Type Stripping');
         } catch (tsError) {
           // If it's invalid or unsupported TypeScript syntax, rethrow the original error
           // with the TypeScript error message added to the stack.
diff --git a/test/es-module/test-typescript-eval.mjs b/test/es-module/test-typescript-eval.mjs
index b38e8c67c50..72ad8dfaaf2 100644
--- a/test/es-module/test-typescript-eval.mjs
+++ b/test/es-module/test-typescript-eval.mjs
@@ -11,7 +11,7 @@ test('eval TypeScript ESM syntax', async () => {
     const text: string = 'Hello, TypeScript!'
     console.log(util.styleText('red', text));`]);
 
-  match(result.stderr, /Type Stripping is an experimental feature and might change at any time/);
+  strictEqual(result.stderr, '');
   match(result.stdout, /Hello, TypeScript!/);
   strictEqual(result.code, 0);
 });
@@ -24,7 +24,7 @@ test('eval TypeScript ESM syntax with input-type module', async () => {
     const text: string = 'Hello, TypeScript!'
     console.log(util.styleText('red', text));`]);
 
-  match(result.stderr, /Type Stripping is an experimental feature and might change at any time/);
+  strictEqual(result.stderr, '');
   match(result.stdout, /Hello, TypeScript!/);
   strictEqual(result.code, 0);
 });
@@ -36,7 +36,7 @@ test('eval TypeScript CommonJS syntax', async () => {
     const text: string = 'Hello, TypeScript!'
     console.log(util.styleText('red', text));`]);
   match(result.stdout, /Hello, TypeScript!/);
-  match(result.stderr, /ExperimentalWarning: Type Stripping is an experimental/);
+  strictEqual(result.stderr, '');
   strictEqual(result.code, 0);
 });
 
@@ -72,7 +72,7 @@ test('TypeScript ESM syntax not specified', async () => {
     `import util from 'node:util'
     const text: string = 'Hello, TypeScript!'
     console.log(text);`]);
-  match(result.stderr, /ExperimentalWarning: Type Stripping is an experimental/);
+  strictEqual(result.stderr, '');
   match(result.stdout, /Hello, TypeScript!/);
   strictEqual(result.code, 0);
 });
@@ -162,7 +162,7 @@ test('check warning is emitted when eval TypeScript CommonJS syntax', async () =
     `const util = require('node:util');
     const text: string = 'Hello, TypeScript!'
     console.log(util.styleText('red', text));`]);
-  match(result.stderr, /ExperimentalWarning: Type Stripping is an experimental/);
+  strictEqual(result.stderr, '');
   match(result.stdout, /Hello, TypeScript!/);
   strictEqual(result.code, 0);
 });
diff --git a/test/es-module/test-typescript-module.mjs b/test/es-module/test-typescript-module.mjs
index 27e3e356739..6a43808b82e 100644
--- a/test/es-module/test-typescript-module.mjs
+++ b/test/es-module/test-typescript-module.mjs
@@ -20,7 +20,7 @@ test('execute an .mts file importing an .mts file', async () => {
     fixtures.path('typescript/mts/test-import-module.mts'),
   ]);
 
-  match(result.stderr, /Type Stripping is an experimental feature and might change at any time/);
+  strictEqual(result.stderr, '');
   match(result.stdout, /Hello, TypeScript!/);
   strictEqual(result.code, 0);
 });
diff --git a/test/es-module/test-typescript.mjs b/test/es-module/test-typescript.mjs
index 74c4a0f120b..52d096b0e0b 100644
--- a/test/es-module/test-typescript.mjs
+++ b/test/es-module/test-typescript.mjs
@@ -35,7 +35,7 @@ test('execute a TypeScript file', async () => {
     fixtures.path('typescript/ts/test-typescript.ts'),
   ]);
 
-  match(result.stderr, /Type Stripping is an experimental feature and might change at any time/);
+  strictEqual(result.stderr, '');
   match(result.stdout, /Hello, TypeScript!/);
   strictEqual(result.code, 0);
 });
@@ -331,3 +331,14 @@ test('execute invalid TypeScript syntax', async () => {
   strictEqual(result.stdout, '');
   strictEqual(result.code, 1);
 });
+
+test('check transform types warning', async () => {
+  const result = await spawnPromisified(process.execPath, [
+    '--experimental-transform-types',
+    fixtures.path('typescript/ts/test-typescript.ts'),
+  ]);
+
+  match(result.stderr, /Transform Types is an experimental feature and might change at any time/);
+  match(result.stdout, /Hello, TypeScript!/);
+  strictEqual(result.code, 0);
+});