Registry / babel-preset-proposal-typescript

babel-preset-proposal-typescript

library4.0.0jsnpmunverified

The `babel-preset-proposal-typescript` (currently v4.0.0) is a Babel preset designed to enable experimental ECMAScript proposals in TypeScript projects that TypeScript itself does not yet natively support. This includes features like async do expressions, record and tuple, pipeline operator, and more, allowing developers to utilize cutting-edge syntax while still leveraging TypeScript's type-checking capabilities for standard features. The preset maintains an active development pace, with major versions typically aligned with updates to its core peer dependencies: `@babel/core` (currently `^7.23.0`) and `typescript` (currently `^5.3.0`). Its primary differentiator is its focused scope: it specifically fills the gap for proposals that the TypeScript team explicitly postpones or chooses not to implement, avoiding redundant transformations with `@babel/preset-typescript` or other standard presets.

npm install babel-preset-proposal-typescript

github ↗package ↗

INSTALL

IMPORT

SIG · BABEL-PRESET-PROPO

babel-preset-proposal-typescript

javascriptv4.0.0

Install

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Import

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Disk

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Pass rate

0/ 6

Env Coverage0 / 6

glibc

18–22

musl

18–22

Install & Compatibility

Where this runs

tested against v? · npm install

Install × environment matrix

Each cell = how many times install + import succeeded across repeated harness runs. Partial = flaky.
glibc = Debian/Ubuntu slim · musl = Alpine Linux

musl

node 18–226 runs

build_error

glibc

node 18–226 runs

build_error

Code

Verified usage

Verified import paths — ran on the pinned version, not inferred.

Babel Preset Configuration

✓ { "presets": ["babel-preset-proposal-typescript"] }

✗ import preset from 'babel-preset-proposal-typescript';

This package is a Babel preset and is not imported directly into JavaScript/TypeScript files. It is configured within your Babel configuration file (e.g., `.babelrc.json` or `babel.config.js`) as an entry in the `presets` array.

Babel Node API Usage

✓ require('babel-preset-proposal-typescript')

✗ import { PresetName } from 'babel-preset-proposal-typescript';

When using the Babel Node API, you might dynamically load presets. Use `require()` to obtain the preset function, which is then passed to Babel's transform functions, typically as part of a configuration object.

Demonstrates how to configure Babel with `babel-preset-proposal-typescript` to compile TypeScript code utilizing experimental ECMAScript proposals like `do expressions`, `record and tuple`, and `pipeline operator`.

{ "plugins": [ // Ensure decorators are enabled if you use them, and are correctly configured. // Babel's order matters: proposals before official features. ], "presets": [ ["@babel/preset-env", { "targets": { "node": "current" } }], "@babel/preset-typescript", "babel-preset-proposal-typescript" ] } // Example index.ts async function runDoExpression() { const result = await do { let x = 10; if (x > 5) { await Promise.resolve(x * 2); } else { x * 3; } }; console.log('Do expression result:', result); } runDoExpression(); const tuple: [string, number] = #['hello', 123]; console.log('Tuple element:', tuple[0]); function pipelineExample(value: number) { return value |> ((x) => x * 2) |> ((x) => x + 1); } console.log('Pipeline result:', pipelineExample(5)); // package.json script // "scripts": { // "build": "babel src/index.ts --out-dir dist --extensions \".ts\"" // }

Debug

Known issues

breakingVersion 4.0.0 requires `@babel/core@^7.23.0` and `typescript@^5.3.0`. Users on older versions of Babel or TypeScript will need to upgrade their peer dependencies.

fix

Ensure `@babel/core` is `^7.23.0` or higher and `typescript` is `^5.3.0` or higher in your `package.json` peer dependencies. Then run `npm install` or `yarn install`.

affects: >=4.0.0

breakingVersion 3.0.0 upgraded the minimum `typescript` peer dependency to `v4.7` and removed some internal plugins. This might cause compatibility issues for projects still using older TypeScript versions.

fix

Upgrade your `typescript` dependency to `^4.7.0` or later. Review your Babel configuration as some previously managed plugins might now be handled natively by TypeScript or are no longer needed.

affects: >=3.0.0 <4.0.0

breakingVersion 2.0.0 introduced breaking changes by bumping both Babel and TypeScript minimum versions and adding new proposals. Specific details might vary, but expect potential configuration and dependency conflicts.

fix

Consult the changelog for `v2.0.0` to identify specific plugin changes or removals. Upgrade your Babel and TypeScript peer dependencies to meet the new requirements.

affects: >=2.0.0 <3.0.0

gotchaSince `v1.5.0`, `nullish-coalescing-operator` and `optional-chaining` transformations were dropped as TypeScript 3.7.0 introduced native support for these features. Relying on this preset for these specific transformations will no longer work.

fix

For `nullish-coalescing-operator` and `optional-chaining`, ensure your project uses TypeScript 3.7.0 or newer and that `@babel/preset-typescript` (or similar) is configured to handle modern TypeScript syntax. This preset is strictly for proposals TypeScript *does not* yet support.

affects: >=1.5.0

gotchaThis preset only transforms proposals which TypeScript does not *currently* support. As TypeScript evolves and adopts new ECMAScript proposals, this preset may remove plugins for those features. This could lead to unexpected behavior if your build relies on the preset transforming a feature that TypeScript has since adopted.

fix

Regularly review the changelog for this preset and the TypeScript release notes. Ensure your Babel configuration remains lean, relying on `@babel/preset-typescript` for standard TypeScript features and this preset only for the explicitly unsupported proposals.

affects: all

Errors

Common errors & fixes

Cannot find module 'babel-preset-proposal-typescript'

The package is not installed or incorrectly referenced in `package.json`.

fix

Ensure `babel-preset-proposal-typescript` is listed in your `devDependencies` and installed: `npm install --save-dev babel-preset-proposal-typescript` or `yarn add -D babel-preset-proposal-typescript`.

Requires Babel '^7.23.0'

Your installed `@babel/core` version does not meet the peer dependency requirement of `babel-preset-proposal-typescript@4.0.0`.

fix

Upgrade `@babel/core` to the required version: `npm install --save-dev @babel/core@^7.23.0` or `yarn add -D @babel/core@^7.23.0`.

Requires TypeScript '^5.3.0'

Your installed `typescript` version does not meet the peer dependency requirement of `babel-preset-proposal-typescript@4.0.0`.

fix

Upgrade `typescript` to the required version: `npm install --save-dev typescript@^5.3.0` or `yarn add -D typescript@^5.3.0`.

Error: .babelrc configuration is invalid. presets[2] must be a string

Incorrect format for the preset entry in `.babelrc` or `babel.config.js`.

fix

Ensure the preset is listed as a simple string `"babel-preset-proposal-typescript"` or an array `["babel-preset-proposal-typescript", { /* options */ }]` if you need to pass options.

Upgrade

Version history

4.0.0latest on npm

Audit

Dependencies

@babel/corerequiredRequired for Babel compilation. The preset integrates with Babel's core functionalities.

typescriptrequiredRequired for TypeScript parsing and type-checking, as this preset augments TypeScript's syntax support.

Agent activity

5 hits · last 30 days

node

Amazon

Resources

githubhttps://github.com/un-ts/babel-preset-proposal-typescript ↗

packagehttps://www.npmjs.com/package/babel-preset-proposal-typescript ↗