Grunt task for running an Express Server that works great with LiveReload + Watch/Regarde
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Latest commit 7489024 Feb 21, 2018


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Simple grunt task for running an Express server that works great with LiveReload + Watch/Regarde

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-express-server --save-dev

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


The express task


In your project's Gruntfile, you can create one or multiple servers:

  express: {
    options: {
      // Override defaults here
    dev: {
      options: {
        script: 'path/to/dev/server.js'
    prod: {
      options: {
        script: 'path/to/prod/server.js',
        node_env: 'production'
    test: {
      options: {
        script: 'path/to/test/server.js'

You can override the default options either in the root of the express config or within each individual server task.

Default options

  express: {
    options: {
      // Override the command used to start the server.
      // (do not use 'coffee' here, the server will not be able to restart
      //  see below at opts for coffee-script support)
      cmd: process.argv[0],

      // Will turn into: `node OPT1 OPT2 ... OPTN path/to/server.js ARG1 ARG2 ... ARGN`
      // (e.g. opts: ['node_modules/coffee-script/bin/coffee'] will correctly parse coffee-script)
      opts: [ ],
      args: [ ],

      // Setting to `false` will effectively just run `node path/to/server.js`
      background: true,

      // Called when the spawned server throws errors
      fallback: function() {},

      // Override node env's PORT
      port: 3000,

      // Override node env's NODE_ENV
      node_env: undefined,

      // Enable Node's --harmony flag
      harmony: false,

      // Consider the server to be "running" after an explicit delay (in milliseconds)
      // (e.g. when server has no initial output)
      delay: 0,

      // Regular expression that matches server output to indicate it is "running"
      output: ".+",

      // Set --debug (true | false | integer from 1024 to 65535, has precedence over breakOnFirstLine)
      debug: false,

      // Set --debug-brk (true | false | integer from 1024 to 65535)
      breakOnFirstLine: false,

      // Object with properties `out` and `err` both will take a path to a log file and
      // append the output of the server. Make sure the folders exist.
      logs: undefined



By default, unless delay or output has been customized, the server is considered "running" once any output is logged to the console, upon which control is passed back to grunt.

Typically, this is:

Express server listening on port 3000

If your server doesn't log anything, the express task will never finish and none of the following tasks, after it, will be executed. For example - if you have a development task like this one:

grunt.registerTask('rebuild', ['clean', 'browserify:scripts', 'stylus', 'copy:images']);
grunt.registerTask('dev', ['rebuild', 'express', 'watch']);

If you run the dev task and your server doesn't log anything, 'watch' will never be started.

This can easily be avoided, if you log something, when server is created like that:

var server = http.createServer( app ).listen( PORT, function() {
    console.log('Express server listening on port ' + PORT);
} );

If you log output before the server is running, either set delay or output to indicate when the server has officially started.

Starting the server

If you have a server defined named dev, you can start the server by running express:dev. The server only runs as long as grunt is running. Once grunt's tasks have completed, the web server stops.

Stopping the server

Similarly, if you start the dev server with express:dev, you can stop the server with express:dev:stop.

With grunt-contrib-watch

  watch: {
    express: {
      files:  [ '**/*.js' ],
      tasks:  [ 'express:dev' ],
      options: {
        spawn: false // for grunt-contrib-watch v0.5.0+, "nospawn: true" for lower versions. Without this option specified express won't be reloaded

grunt.registerTask('server', [ 'express:dev', 'watch' ])

Important: Note that the spawn: false options only need be applied to the watch target regarding the express task. You may have other watch targets that use spawn: true, which is useful, for example, to reload CSS and not LESS changes.

watch: {
  options: {
    livereload: true
  express: {
    files:  [ '**/*.js' ],
    tasks:  [ 'express:dev' ],
    options: {
      spawn: false
  less: {
    files: ["public/**/*.less"],
    tasks: ["less"],
    options: {
      livereload: false
  public: {
    files: ["public/**/*.css", "public/**/*.js"]


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

  • v0.5.3 - Update peerDeps and enable travis build against Node 4
  • v0.5.2 - Add hardStop flag (#99)
  • v0.5.1 - Add harmony flag (#86)
  • v0.5.0 - Add breakOnFirstLine option, support for debug ports and fix bugs. Details: (#68, #70, #73)
  • v0.4.19 – Use process.env.PORT before 3000 (#59)
  • v0.4.18 – Fix for when running the node debugger (#57)
  • v0.4.17 – Update devDependencies...again
  • v0.4.16 – Update devDependencies
  • v0.4.15 – Recommend using local coffee with additional arguments (#50)
  • v0.4.14 – Attempt to fix issues running Coffeescript (#54)
  • v0.4.13 – Add --nodejs for Coffeescript users (#37)
  • v0.4.12 – Only remove this task's listeners (#39)
  • v0.4.11 – Revert v0.4.10 until Travis can reproduce it
  • v0.4.10 – Another attempt to fix #28 & #30's server restarting issue (#31)
  • v0.4.9 – Revert v0.4.8 until #30 is resolved
  • v0.4.8 – Fix issue with start/restarting multiple instances (#29)
  • v0.4.7 – Remove broken error option (#27)
  • v0.4.6 – Store running servers on process._servers[target] (#22)
  • v0.4.5 – Support multiple servers running at once (#23)
  • v0.4.4 - Fix for using grunt-env to change environments, thanks to @FredrikAppelros (#20)
  • v0.4.3 - Add cmd option that defaults to Node, but can be set to coffee for Coffeescript support, thanks to @JonET (#15)
  • v0.4.2 - Add debug option that gets enables Node's debugger, ideally for use with node-inspector
  • v0.4.1 - Add node_env option that sets NODE_ENV when running the server & restores original env upon closing, thanks to @jgable!
  • v0.4.0
    • Add delay option that, when set, passes control back to grunt after timeout
    • Add output regular expression option that, when set, waits for matching message before passing control back to grunt
  • v0.3.1 - Try to force notification that express task has finished as much as possible
  • v0.3.0 - express is now a multitask with customizable options, better error handling and :stop task
  • v0.2.0
    • Change express-server task to express
    • Config is set via express: '...' instead of server: { script: '...' }
  • v0.1.0 - Initial import from Genesis Skeleton & release

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