How to run a shell command from Grunt task function

Question

I'm trying to move some icons in my app directory based on a function i have inside my Gruntfile.js . Would it be possible to do something like this? I've tried the following (going into dev or staging folder and copying all files to the previous directory), but coudn't get it to work. Thanks in advance.

grunt.registerTask('setAppIcon', 'Task that sets the app icon', function(environment) {
    if (environment.toLowerCase() == "development") {

        grunt.task.run(['exec:command:cd app/lib/extras/res/icon/ios/dev && cp -a . ../']);

    } else if (environment.toLowerCase() == "staging") {

        grunt.task.run(['exec:command:cd app/lib/extras/res/icon/ios/staging && cp -a . ../']);

    } 
});

Answer 1

Yes, it's possible to achieve your requirement, however, when you invoke the grunt.task.run command inside your function (ie custom task) you need to provide a reference to a task to run.

If you define a separate Target , (Let's call call them copy_dev and copy_staging - as shown in the example below) , for each cd ... && cp ... command in the grunt-exec Task it should work successfully.

---

Gruntfile.js

The following Gruntfile.js gist shows how this can be achieved:

module.exports = function (grunt) {

  grunt.loadNpmTasks('grunt-exec');

  grunt.initConfig({
    exec: {
      copy_dev: {
        cmd: 'cd app/lib/extras/res/icon/ios/dev && cp -a . ../'
      },
      copy_staging: {
        cmd: 'cd app/lib/extras/res/icon/ios/staging && cp -a . ../'
      }
    }
  });

  grunt.registerTask('setAppIcon', 'Task that sets the app icon', function() {
    var environment = process.env.NODE_ENV;

    // Exit early if NODE_ENV variable has not been set.
    if (!environment) {
      grunt.log.writeln(
        '\"setAppIcon\"" task failed - NODE_ENV has not been set.'['yellow']
      )
      return
    }

    if (environment.toLowerCase() == "development") {
      grunt.task.run('exec:copy_dev');
      grunt.log.writeln('>> Copying icons from \"dev\"...')
    } else if (environment.toLowerCase() == "staging") {
      grunt.task.run('exec:copy_staging');
      grunt.log.writeln('>> Copying icons from \"staging\"...')
    }
  });

  grunt.registerTask('default', [ 'setAppIcon' ]);
};

---

Additional notes

Inside the custom task/function named setAppIcon we obtain the current node environment using nodes builtin process.env

When running $ grunt via your CLI (using the gist shown above) , and assuming your process.env.NODE_ENV variable has not been set, or it has possibly been unset by running $ unset NODE_ENV , you will see the following message:

"setAppIcon"" task failed - NODE_ENV has not been set.

However, if the process.env.NODE_ENV variable has been set to either development or staging the files will be copied as expected.

For example running either of the following via your CLI will work successfully:

$ export NODE_ENV=development && grunt

or

$ export NODE_ENV=staging && grunt

You will also see either of the following messages logged to the console:

>> Copying icons from "dev"...

or

>> Copying icons from "staging"...

After process.env.NODE_ENV has been set to either development or staging then just running $ grunt via your CLI, will copy files according to which environment is set.