feat: drop support for outdated Node.js versions (#324)

BREAKING CHANGE: only Node.js LTS versions v18 and up are now supported

README.md

@@ -6,11 +6,9 @@
 - Blazing fast on-demand TypeScript & ESM compilation
 - Works in both [CommonJS and ESM packages](https://nodejs.org/api/packages.html#type)
 - Supports next-gen TypeScript extensions (`.cts` & `.mts`)
-- Supports `node:` import prefixes
 - Hides experimental feature warnings
 - TypeScript REPL
 - Resolves `tsconfig.json` [`paths`](https://www.typescriptlang.org/tsconfig#paths)
-- Tested on Linux & Windows with Node.js v12~20
 
 > **💡 Protip: Looking to bundle your TypeScript project?**
 >
@@ -45,7 +43,7 @@ How does it compare to [ts-node](https://github.com/TypeStrong/ts-node)? Checkou
 tsx strives to:
 1. Enhance Node.js with TypeScript compatibility
 2. Improve ESM <-> CJS interoperability
-3. Support the latest major version of Node.js v12 and up _(likely to change in the future)_
+3. Support the [LTS versions of Node.js](https://endoflife.date/nodejs)
 
 ## Install
 

package.json

@@ -47,6 +47,9 @@
 	"lint-staged": {
 		"*.{js,ts,mjs,mts,cjs,cts,json}": "pnpm lint"
 	},
+	"engines": {
+		"node": ">=18.0.0"
+	},
 	"dependencies": {
 		"esbuild": "~0.18.20",
 		"get-tsconfig": "^4.7.2",

src/cjs/index.ts

@@ -11,7 +11,6 @@ import type { TransformOptions } from 'esbuild';
 import { installSourceMapSupport } from '../source-map';
 import { transformSync, transformDynamicImport } from '../utils/transform';
 import { resolveTsPath } from '../utils/resolve-ts-path';
-import { nodeSupportsImport, supportsNodePrefix } from '../utils/node-features';
 
 const isRelativePathPattern = /^\.{1,2}\//;
 const isTsFilePatten = /\.[cm]?tsx?$/;
@@ -66,7 +65,7 @@ const transformer = (
 
 	let code = fs.readFileSync(filePath, 'utf8');
 
-	if (filePath.endsWith('.cjs') && nodeSupportsImport) {
+	if (filePath.endsWith('.cjs')) {
 		const transformed = transformDynamicImport(filePath, code);
 		if (transformed) {
 			code = applySourceMap(transformed, filePath);
@@ -126,15 +125,8 @@ Object.defineProperty(extensions, '.mjs', {
 	enumerable: false,
 });
 
-// Add support for "node:" protocol
 const defaultResolveFilename = Module._resolveFilename.bind(Module);
 Module._resolveFilename = (request, parent, isMain, options) => {
-	// Added in v12.20.0
-	// https://nodejs.org/api/esm.html#esm_node_imports
-	if (!supportsNodePrefix && request.startsWith('node:')) {
-		request = request.slice(5);
-	}
-
 	if (
 		tsconfigPathsMatcher
 

src/esm/index.ts

@@ -11,4 +11,3 @@ if (
 }
 
 export * from './loaders.js';
-export * from './loaders-deprecated.js';

src/esm/loaders.ts

@@ -7,9 +7,6 @@ import type {
 import type { TransformOptions } from 'esbuild';
 import { transform, transformDynamicImport } from '../utils/transform';
 import { resolveTsPath } from '../utils/resolve-ts-path';
-import {
-	supportsNodePrefix,
-} from '../utils/node-features';
 import {
 	applySourceMap,
 	tsconfigPathsMatcher,
@@ -164,12 +161,6 @@ export const resolve: resolve = async function (
 	defaultResolve,
 	recursiveCall,
 ) {
-	// Added in v12.20.0
-	// https://nodejs.org/api/esm.html#esm_node_imports
-	if (!supportsNodePrefix && specifier.startsWith('node:')) {
-		specifier = specifier.slice(5);
-	}
-
 	// If directory, can be index.js, index.ts, etc.
 	if (isDirectoryPattern.test(specifier)) {
 		return await tryDirectory(specifier, context, defaultResolve);

src/utils/node-features.ts

@@ -8,24 +8,6 @@ const compareNodeVersion = (version: Version) => (
 	|| nodeVersion[2] - version[2]
 );
 
-export const nodeSupportsImport = (
-	// v13.2.0 and higher
-	compareNodeVersion([13, 2, 0]) >= 0
-
-	// 12.20.0 ~ 13.0.0
-	|| (
-		compareNodeVersion([12, 20, 0]) >= 0
-		&& compareNodeVersion([13, 0, 0]) < 0
-	)
-);
-
-export const supportsNodePrefix = (
-	compareNodeVersion([16, 0, 0]) >= 0
-	|| compareNodeVersion([14, 18, 0]) >= 0
-);
-
-export const nodeSupportsDeprecatedLoaders = compareNodeVersion([16, 12, 0]) < 0;
-
 /**
  * Node.js loaders are isolated from v20
  * https://github.com/nodejs/node/issues/49455#issuecomment-1703812193

tests/utils/node-versions.ts

@@ -1,17 +1,12 @@
 export const nodeVersions = [
-	'18',
 	'20',
 	...(
 		(
 			process.env.CI
 			&& process.platform !== 'win32'
 		)
 			? [
-				'12.20.0', // CJS named export detection added
-				'12',
-				'14',
-				'16',
-				'17',
+				'18',
 			] as const
 			: [] as const
 	),