There are a number of built-in tasks that npm can run for you. 0:00 The most common is test. 0:04 You're often encouraged to install test frameworks and 0:07 build systems globally with the -g flag. 0:10 But that can be a little overkill if you're working on different projects with 0:14 potentially different versions. 0:17 Let's install our depth dependences now by running npm install. 0:20 The install command installs all npm modules that are part of your project. 0:32 In other words, third party modules that your project depends on. 0:38 But it also installs development dependencies, 0:42 that is, modules that you use during development. 0:45 Such modules that can compile Sass, combine multiple JavaScript files, 0:48 or to test your code to make sure it works. 0:54 In this example, I've installed the JavaScript testing framework Mocha for 0:59 testing my JavaScript. 1:03 How do you run Mocha here? 1:06 In your node_modules folder, there's a hidden directory, .bin. 1:08 And in there, there are command line executables like Mocha. 1:15 So you can type, node_modules/.bin/mocha. 1:20 And it runs. 1:26 However, you can run executables from npm without typing in this long command. 1:28 Let's update the test task in our scripts object with the Mocha command. 1:35 This will run any Mocha test in the project. 1:50 What we’ve done here is created a test task. 1:54 Now you can run it by typing npm run test. 1:58 Npm can run any binary or command line application. 2:08 See how much easier this is? 2:12 Now that we don’t need to remember or type that full path in to Mocha. 2:14 We can make it even easier by ditching run. 2:20 Because test is a built-in task, you can leave out the run, 2:23 and simply type npm test. 2:28