This package has been deprecated

Author message:

This package is no longer maintained


2.0.0 • Public • Published

grunt-flow Build Status

Validates JavaScript with Facebook's Flow Library

Getting Started

This plugin requires Grunt.

If you haven't used Grunt before, be sure to check out the Getting Started guide, as it explains how to create a Gruntfile as well as install and use Grunt plugins. Once you're familiar with that process, you may install this plugin with this command:

npm install grunt-flow --save-dev

Once the plugin has been installed, it may be enabled inside your Gruntfile with this line of JavaScript:


The "flow" task


In your project's Gruntfile, add a section named flow to the data object passed into grunt.initConfig().

  flow: {
    options: {}
  files: {}


Type: String Default value: color

A string value that is used to determine flow output styling. There are two options to choose from:

  1. color - This will colorize the output from flow
  2. none - This will keep the default standard text output from flow without any color.


Type: Boolean Default value: true

If set, flow instead of flow check will be used. This starts the background flow server, which is much more performant at re-running checks. This should used in conjunction with grunt-contrib-watch:

  flow: {
    watch: {
      src: 'src/**/*.js',
      options: {
        server: true
  watch : {
      flow: {
        files: ['src/**/*.js'],
        tasks: ['flow'] // Get the status from the server

// Run 'flow' before the watch task to start the server
grunt.registerTask('default', ['flow', 'watch']);


Type: String Default value: .flowconfig

Path to the configuration file for flow. Default is .flowconfig in the current directory.



Flow requires that you have a .flowconfig file in the root of you project folder. Below is an example of what your .flowconfig file should look like:

# .flowconfig 

You can look up more information on the .flowconfig file on the flow website

Note that you can set the path to configuration file with options.config.


Within your Gruntfile.js, add the following code to enable colorized output for flow.

  flow: {
    options: {
        style: 'color'
    files: {}  // Flow doesn't use this, but it is needed for Grunt to run properly


In lieu of a formal styleguide, take care to maintain the existing coding style. Add unit tests for any new or changed functionality. Lint and test your code using Grunt.

Release History

v1.0.3 - Fixed logic so that all error codes above 0 cause a grunt failure

v1.0.2 - Added server option to allow for using the flow background server with the grunt-contrib-watch task.

v1.0.1 - Added logic to correctly exit task on Flow error.

v1.0.0 - Updated to latest version of flow (v0.14.0)

v0.0.3 - Fixed colorized output

v0.0.2 - Added style option to enable colorized output

v0.0.1 - Initial release


Copyright (c) 2015 Jake Larson. Licensed under the MIT license.

Package Sidebar


Weekly Downloads






Last publish


  • larsonjj