rollup-plugin-flow-entry

0.3.6 verified Mon Apr 27 auth: no javascript

Rollup plugin that generates .js.flow files from original source for Flow type checking. Current stable version 0.3.6. Released June 2020, last updated ~2020. Creates a re-export file alongside bundled output so Flow can find un-bundled types. Key differentiator: works with Rollup code splitting and @rollup/plugin-multi-entry, supports custom source mappings for TypeScript projects.

Common errors

error Error: Could not resolve entry module ↓

cause Missing or incorrect input file path relative to rollup config.

fix

Ensure input path matches actual file location, e.g., 'src/index.js'.

Warnings

gotcha The .js.flow file is generated but not automatically removed on rollup -c rebuild if the plugin is removed. ↓

fix Manually delete generated .js.flow files when changing plugin configuration.

gotcha Using mode option incorrectly (e.g., 'strict' instead of 'strict-local') causes no generation of .js.flow file. ↓

fix Use valid mode values: undefined, 'local', 'strict-local', or 'all'.

deprecated Integration with @rollup/plugin-multi-entry may not be maintained; behavior may change. ↓

fix Test plugin with your version of @rollup/plugin-multi-entry and consider alternatives.

Install

npm install rollup-plugin-flow-entry

yarn add rollup-plugin-flow-entry

pnpm add rollup-plugin-flow-entry

Imports

default

wrong

const flowEntry = require('rollup-plugin-flow-entry')

correct

import flowEntry from 'rollup-plugin-flow-entry'

ESM default export; CommonJS require works but is discouraged for modern Rollup configs.

flowEntry
wrong
```
export default { plugins: [flowEntry] }
```
correct
```
export default { plugins: [flowEntry()] }
```
Plugin must be instantiated (called as function), not passed as reference.
flowEntry (with options)
wrong
```
flowEntry(mode = 'strict-local')
```
correct
```
flowEntry({ mode: 'strict-local' })
```
Options are passed as an object literal, not as assignment.

Quickstart

Configure Rollup to generate a .js.flow file alongside the bundle, pointing to original Flow source.

// rollup.config.js
import flowEntry from 'rollup-plugin-flow-entry';

export default {
  input: 'src/index.js',
  output: {
    file: 'lib/index.js',
    format: 'cjs'
  },
  plugins: [
    flowEntry()
  ]
};