run-when1.js

import runWhen from 'run-when';

runWhen([
  {
    glob: ['app/components/index.js', 'app/__tests__/**'],
    task(paths) {
      console.log('This will be called!');
    }
  },
  {
    glob: ['!package.json'],
    task(paths) {
      return Promise.resolve('You can return a promise from your task');
    }
  },
  {
    // Optionally pass changed files
    changedFiles: () => Promise.resolve(['app/index.js', 'app/components/header.jsx']),
    glob: ['app/components/**'],
    task(paths) {
      console.log(paths === ['app/components/header.jsx']);
    }
  }
]);