flow-webpack-plugin v1.2.0

flow-webpack-plugin

A webpack plugin allowing to call Flow type checker during each webpack compilation.

Key features

• It doesn't require flow to be in $PATH.
• No dependencies. Plugin can reuse project's flow-bin installation.
• It can make webpack to exit with non-zero return code, if flow validation fails.
• It works per project, not per file.

Installation

Run in you project directory:

npm install --save-dev flow-webpack-plugin flow-bin

or using yarn:

yarn add flow-webpack-plugin flow-bin --dev

Add to your webpack configuration file webpack.config.js:

const FlowWebpackPlugin = require('flow-webpack-plugin')

module.exports = {
    plugins: [
        new FlowWebpackPlugin(),
        // ...
    ],
    // ...
}

Note: flow-bin package is not a hard dependency. If flow is already installed on your system, it can be reused through flowPath option.

Screenshots

Valid codebase:

Flow validation error:

Configuration

Constructor of FlowWebpackPlugin accepts optional configuration object of following properties:

const FlowWebpackPlugin = require('flow-webpack-plugin')

new FlowWebpackPlugin({
    failOnError: false,
    failOnErrorWatch: false,
    reportingSeverity: 'error',
    printFlowOutput: true,
    flowPath: require.main.require('flow-bin'),
    flowArgs: ['--color=always'],
    verbose: false,
    callback: (result) => {}
})

Type annotations strip

This plugin performs type validation of the code. To remove the Flow type annotations and create pure Javascript code babel-plugin-transform-flow-strip-types can be used.