Example usage of ng-constant to create environment variables.

Gruntfile.js

grunt.initConfig({
  ngconstant: {
    dev: [
      {
        dest: 'path/to/constants.js',
        name: 'Constants',
        constants: {
          '<constant name>': grunt.file.readJSON('path/to/dev.json'),
        }
      }
    ],
    prod: [ // same as dev task except the JSON source file is different
      {
        dest: 'path/to/constants.js', 
        name: 'Constants', 
        constants: {
          '<constant name>': grunt.file.readJSON('path/to/prod.json'),
        }
      }
    ], 
  },
})