From 2ee876c50a2204dc8a02d8b97c2acc1a21e222ec Mon Sep 17 00:00:00 2001 From: Marco Ippolito Date: Thu, 24 Oct 2024 20:27:58 +0200 Subject: [PATCH] module: add module.stripTypeScriptTypes PR-URL: https://github.com/nodejs/node/pull/55282 Fixes: https://github.com/nodejs/node/issues/54300 Reviewed-By: Yagiz Nizipli Reviewed-By: Joyee Cheung Reviewed-By: Chemi Atlow Reviewed-By: Paolo Insogna Reviewed-By: Chengzhong Wu Reviewed-By: James M Snell Reviewed-By: Richard Lau --- doc/api/module.md | 101 ++++++++++++++++ lib/internal/main/eval_string.js | 6 +- lib/internal/modules/cjs/loader.js | 10 +- lib/internal/modules/esm/get_format.js | 5 +- lib/internal/modules/esm/translators.js | 8 +- lib/internal/modules/helpers.js | 75 +----------- lib/internal/modules/typescript.js | 146 +++++++++++++++++++++++ lib/module.js | 3 +- test/parallel/test-bootstrap-modules.js | 1 + test/parallel/test-module-strip-types.js | 92 ++++++++++++++ 10 files changed, 358 insertions(+), 89 deletions(-) create mode 100644 lib/internal/modules/typescript.js create mode 100644 test/parallel/test-module-strip-types.js diff --git a/doc/api/module.md b/doc/api/module.md index 7a1928da5b05a2..0b86ddf8307e2f 100644 --- a/doc/api/module.md +++ b/doc/api/module.md @@ -352,6 +352,105 @@ changes: Register a module that exports [hooks][] that customize Node.js module resolution and loading behavior. See [Customization hooks][]. +## `module.stripTypeScriptTypes(code[, options])` + + + +> Stability: 1.0 - Early development + +* `code` {string} The code to strip type annotations from. +* `options` {Object} + * `mode` {string} **Default:** `'strip'`. Possible values are: + * `'strip'` Only strip type annotations without performing the transformation of TypeScript features. + * `'transform'` Strip type annotations and transform TypeScript features to JavaScript. + * `sourceMap` {boolean} **Default:** `false`. Only when `mode` is `'transform'`, if `true`, a source map + will be generated for the transformed code. + * `sourceUrl` {string} Specifies the source url used in the source map. +* Returns: {string} The code with type annotations stripped. + `module.stripTypeScriptTypes()` removes type annotations from TypeScript code. It + can be used to strip type annotations from TypeScript code before running it + with `vm.runInContext()` or `vm.compileFunction()`. + By default, it will throw an error if the code contains TypeScript features + that require transformation such as `Enums`, + see [type-stripping][] for more information. + When mode is `'transform'`, it also transforms TypeScript features to JavaScript, + see [transform TypeScript features][] for more information. + When mode is `'strip'`, source maps are not generated, because locations are preserved. + If `sourceMap` is provided, when mode is `'strip'`, an error will be thrown. + +_WARNING_: The output of this function should not be considered stable across Node.js versions, +due to changes in the TypeScript parser. + +```mjs +import { stripTypeScriptTypes } from 'node:module'; +const code = 'const a: number = 1;'; +const strippedCode = stripTypeScriptTypes(code); +console.log(strippedCode); +// Prints: const a = 1; +``` + +```cjs +const { stripTypeScriptTypes } = require('node:module'); +const code = 'const a: number = 1;'; +const strippedCode = stripTypeScriptTypes(code); +console.log(strippedCode); +// Prints: const a = 1; +``` + +If `sourceUrl` is provided, it will be used appended as a comment at the end of the output: + +```mjs +import { stripTypeScriptTypes } from 'node:module'; +const code = 'const a: number = 1;'; +const strippedCode = stripTypeScriptTypes(code, { mode: 'strip', sourceUrl: 'source.ts' }); +console.log(strippedCode); +// Prints: const a = 1\n\n//# sourceURL=source.ts; +``` + +```cjs +const { stripTypeScriptTypes } = require('node:module'); +const code = 'const a: number = 1;'; +const strippedCode = stripTypeScriptTypes(code, { mode: 'strip', sourceUrl: 'source.ts' }); +console.log(strippedCode); +// Prints: const a = 1\n\n//# sourceURL=source.ts; +``` + +When `mode` is `'transform'`, the code is transformed to JavaScript: + +```mjs +import { stripTypeScriptTypes } from 'node:module'; +const code = ` + namespace MathUtil { + export const add = (a: number, b: number) => a + b; + }`; +const strippedCode = stripTypeScriptTypes(code, { mode: 'transform', sourceMap: true }); +console.log(strippedCode); +// Prints: +// var MathUtil; +// (function(MathUtil) { +// MathUtil.add = (a, b)=>a + b; +// })(MathUtil || (MathUtil = {})); +// # sourceMappingURL=data:application/json;base64, ... +``` + +```cjs +const { stripTypeScriptTypes } = require('node:module'); +const code = ` + namespace MathUtil { + export const add = (a: number, b: number) => a + b; + }`; +const strippedCode = stripTypeScriptTypes(code, { mode: 'transform', sourceMap: true }); +console.log(strippedCode); +// Prints: +// var MathUtil; +// (function(MathUtil) { +// MathUtil.add = (a, b)=>a + b; +// })(MathUtil || (MathUtil = {})); +// # sourceMappingURL=data:application/json;base64, ... +``` + ### `module.syncBuiltinESMExports()`