esbuild-plugin-flow

0.3.2 verified Fri May 01 auth: no javascript

Esbuild plugin for stripping Flow type annotations using flow-remove-types. Current version 0.3.2 (latest). Installation requires direct GitHub URL. Designed for custom build scripts, not CLI. Key differentiator: integrates Flow type stripping into esbuild bundling. Alternatives like @babel/preset-flow require Babel; this plugin is lightweight. Entry point files are not processed (known limitation). Options include regex for file matching and optional force flag to strip even without @flow pragma.

Common errors

error Cannot find module 'esbuild-plugin-flow' ↓

cause Package installed from GitHub URL, but Node.js module resolution may not find it if global symlinks are missing.

fix

Ensure you ran 'npm install https://github.com/dalcib/esbuild-plugin-flow' from the project root.

error TypeError: flow is not a function ↓

cause Using import instead of require, or not invoking the default export correctly.

fix

Use const flow = require('esbuild-plugin-flow'); flow(/regex/);

error Error: The plugin must be a function or an object with a 'name' and 'setup' function. ↓

cause Passing a string instead of a RegExp to the flow function, causing esbuild to receive an invalid plugin object.

fix

Ensure the argument to flow() is a RegExp, e.g., /\.flow\.jsx?$/

Warnings

breaking Entry point files are not processed by this plugin due to esbuild limitations; Flow types in entry point will not be stripped. ↓

fix Move entry point content into a non-entry module or use a separate build step for the entry file.

gotcha Installation requires GitHub URL, not npm registry. 'npm i --dev esbuild-plugin-flow' will fail. ↓

fix Install via: npm i --dev https://github.com/dalcib/esbuild-plugin-flow

gotcha The regex argument must be a RegExp object; passing a string will cause unexpected behavior. ↓

fix Pass a RegExp literal, e.g., /\.flow\.jsx?$/

gotcha Plugin does not support ESM; using import syntax will fail. ↓

fix Use require('esbuild-plugin-flow') instead.

Install

npm install esbuild-plugin-flow

yarn add esbuild-plugin-flow

pnpm add esbuild-plugin-flow

Imports

esbuild-plugin-flow
wrong
```
import flow from 'esbuild-plugin-flow'
```
correct
```
const flow = require('esbuild-plugin-flow')
```
Package does not export ESM; CommonJS require is required.
default
```
const flow = require('esbuild-plugin-flow')
```
Default export is a function that returns a plugin.
flow (function)
wrong
```
flow('regex')
```
correct
```
flow(/regex/, false)
```
First argument must be a RegExp object, not a string.

Quickstart

Basic usage: require the plugin, pass a RegExp matching .flow.js or .flow.jsx files, and include in esbuild plugins array.

const esbuild = require('esbuild');
const flow = require('esbuild-plugin-flow');
esbuild.build({
  entryPoints: ['index.js'],
  outfile: 'dist/bundle.js',
  bundle: true,
  plugins: [flow(/\.flow\.jsx?$/)]
}).catch(() => process.exit(1));