@babel/plugin-transform-flow-strip-types

What is @babel/plugin-transform-flow-strip-types?

The @babel/plugin-transform-flow-strip-types npm package is a plugin for Babel, a JavaScript compiler, that removes type annotations from Flow, a static type checker for JavaScript. This allows developers to write type-safe code during development and strip out these annotations for production builds, resulting in clean JavaScript that can be executed in environments that do not support Flow.

What are @babel/plugin-transform-flow-strip-types's main functionalities?

Stripping Flow Type Annotations

This feature removes Flow type annotations from your JavaScript files, converting typed code into plain JavaScript. The code sample shows a function with Flow types that are stripped out after transformation.

import { foo } from 'bar';
function square(n: number): number {
  return n * n;
}
// Transformed to:
import { foo } from 'bar';
function square(n) {
  return n * n;
}

Other packages similar to @babel/plugin-transform-flow-strip-types

@babel/plugin-transform-typescript

Similar to @babel/plugin-transform-flow-strip-types, this Babel plugin strips TypeScript annotations from the code. While both plugins serve a similar purpose of removing type annotations, they cater to different type systems: Flow for the former and TypeScript for the latter.

babel-plugin-transform-flow-comments

This plugin also deals with Flow types but instead of stripping them, it converts them into comments. This can be useful for preserving type annotations in the transpiled output without affecting the runtime behavior.

README

@babel/plugin-transform-flow-strip-types

Strip flow type annotations from your output code.

See our website @babel/plugin-transform-flow-strip-types for more information.

Install

Using npm:

npm install --save-dev @babel/plugin-transform-flow-strip-types

or using yarn:

yarn add @babel/plugin-transform-flow-strip-types --dev

Changelog

v7.26.5 (2025-01-10)

:eyeglasses: Spec Compliance

• babel-parser
  • #17011 Allow the dynamic import.defer() form of import defer (@babel-bot)

:bug: Bug Fix

• babel-plugin-transform-block-scoped-functions
  • #17024 chore: Avoid calling isInStrictMode in Babel 7 (@liuxingbaoyu)
• babel-plugin-transform-typescript
  • #17026 fix: Correctly generate exported const enums in namespace (@liuxingbaoyu)
• babel-parser
  • #17045 [estree] Unify method type parameters handling (@JLHwung)
  • #17013 fix: Correctly set position for @(a.b)() (@liuxingbaoyu)
  • #16996 [estree] Adjust the start loc of class methods with type params (@nicolo-ribaudo)
• babel-generator, babel-parser, babel-plugin-transform-flow-strip-types, babel-types
  • #17028 Support flow jsx opening element type arguments (@JLHwung)
• babel-compat-data, babel-preset-env
  • #17031 fix: More accurate transform-typeof-symbol compat data (@liuxingbaoyu)
• babel-generator, babel-parser, babel-types
  • #17019 Fix incomplete visitor keys (@JLHwung)

:microscope: Output optimization

• babel-plugin-transform-nullish-coalescing-operator
  • #16612 Improve nullish coalescing operator output (@liuxingbaoyu)