Run any command on recently changed file via Grunt

gruntfile.js

'use strict'

module.exports = function (grunt) {
  grunt.initConfig({
    options: {
      command: 'touch',
      args: '',
      filepath: '',
      file: ''
    },

    watch: {
      files: ['js/*.js'],
      tasks: ['changelog', 'shell'],
      options: {
        spawn: false
      }
    },

    shell: {
      run: {
        command: '<%= options.command %> <%= options.file %> <%= options.args %>'
      }
    },

    file_append: {
      append: {
        files: {
          'commands.log': {
            prepend: '## Command run: ' +
              '"<%= options.command %> <%= options.file %> <%= options.args %>" \n## ' +
              new Date() + '\n\n'
          }
        }
      }
    }
  })

  // all npm packages we need:
  // npm i grunt-contrib-watch grunt-shell grunt-file-append
  require('load-grunt-tasks')(grunt)

  grunt.registerTask('changelog', function () {
    if (!grunt.file.exists('commands.log')) {
      grunt.file.write('commands.log', '')
    }
    grunt.task.run('file_append')
    grunt.task.run('shell')
  })

  grunt.event.on('watch', function (action, filepath) {
    grunt.config(['options', 'filepath'], filepath)
    grunt.config(['options', 'file'], filepath.replace(/^.*[\\\/]/, ''))
    grunt.log.ok('"' + grunt.template.process('<%= options.command %>') +
      ' ' + filepath + ' ' + grunt.template.process('<%= options.args %>') +
      '" has been runned')
  })
}