grunt-flow-type-check

Run Facebook's Flow static type checker

Getting Started

This plugin requires Grunt >=0.4.0

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-type-check --save-dev

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

grunt.loadNpmTasks('grunt-flow-type-check');

The "flow" task

Run this task with the grunt flow command.

Flow is a static type checker, designed to find type errors in JavaScript programs. Typed Flow code easily transforms down to regular JavaScript, so it runs anywhere.

Overview

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

grunt.initConfig({
  flow: {
    app: {
      src: 'src/',            // `.flowconfig` folder
      options: {
        background: false,    // Watch/Server mode
        all: false,           // Check all files regardless
        lib: '',              // Library directory
        stripRoot: false,     // Relative vs Absolute paths
        weak: false,          // Force weak check
        showAllErrors: false, // Show more than 50 errors
      }
    }
  }
});

Options

src

Type: String Default value: .

Default location of .flowconfig

options.weak

Type: Boolean Default value: false

Use the weak option to check the files.

options.lib

Type: String Default value: ``

Library folder. This can be defined here or in flowconfig.

options.showAllErrors

Type: Boolean Default value: false

By default only the first 50 errors are shown. This will show all of them.

options.stripRoot

Type: Boolean Default value: false

Use relative paths instead of absolute

options.all

Type: Boolean Default value: false

Checks all files regardless of if they have /* @flow */ at the top. Use this with care.

options.background

Type: Boolean Default value: false

Run the Flow server in the background. This is used in conjunction with watch.

Usage Examples

Basic

By default we check for .flowconfig in the root directory and then run flow check

grunt.initConfig({
  flow: {
    app: {
      src: '.',
      options: {
        background: false,
      }
    }
  },
});

Watch

Running flow check each time can be slow. Alternatively, you can run the Flow server in the background and use grunt-contrib-watch to get any current errors when a files changes.

grunt.initConfig({
  flow: {
    watch: {
      src: '.',
      options: {
        // Task-specific options go here.
        background: true
      }
    }
  },
  watch : {
      flow: {
        files: ['src/**/*.jsx'],
        tasks: ['flow:watch:status'] // Get the status from the server
      }
    }
});

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

Single File

You can also run a single file at a time through flow, however this it not recommended for projects with multiple files and/or external dependencies.

grunt.initConfig({
  flow: {
    app: {
      options: {
        showAllErrors: false, // This the only option avaiable in this mode
      },
      files: {
        src: ['src/**/*.js'] // Will run flow individually on each .js file in the src/ directory
      }
    }
  },
});

Contributing

Please take care to maintain the existing coding style. Add unit tests for any new or changed functionality. Lint and test your code using 'grunt test'.

Release History

• v0.4.4 - Switched to flow-bin
• v0.4.3 - Updated binaries and task to support flow 0.4.0
• v0.4.2 - Refactor and removed extraneous option
• v0.4.1 - Fixed bug where watch didn't work
• v0.4.0 - Added single file check, colors and Flow binaries to 0.1.2
• v0.3.0 - Added additional options
• v0.2.1 - Fixed path issue for Flow binaries
• v0.2.0 - Added watch support
• v0.1.0 - Initial Release