Using npm with an Existing Project

Most of your time working as a developer won't be spent creating new applications, but rather maintaining existing applications. npm is useful throughout the lifetime of a application, so let's practice using npm with an existing project.

In this project, you'll:

clone an existing project from a GitHub repository;
use npm to install the project's dependencies;
run each of the project's npm scripts;
use npm to remove a dependency;
and use npm to update a dependency.

Phase 1: Using npm with an existing project

Let's get started!

Phase 1A: Setting up the project

To set up the project, clone the following GitHub repository:

https://github.com/appacademy-starters/javascript-using-npm-with-an-existing-project

Then use npm to install the project's dependencies.

Phase 1B: Running the provided scripts

After installing the project's dependencies, you can test your project by running each of the provided npm scripts that are defined in the package.json file:

{
  "scripts": {
    "start": "node index.js",
    "test": "mocha"
  }
}

Running the start script will start the application and display three knock-knock jokes in the terminal:

Knock, knock.
Who’s there?
Abby.
Abby who?
Abby birthday to you!

Knock, knock.
Who’s there?
Lettuce.
Lettuce who?
Lettuce in. It's cold out here!

Knock, knock.
Who’s there?
Bed.
Bed who?
Bed you can not guess who I am.

Running the test script will run a single unit test and display the following output:

The getJoke() function
    ✓ should return a joke

  1 passing (5ms)

Phase 1C: Removing a dependency

The project contains three development dependencies: mocha, chai, and chai-spies. mocha and chai are both being used to unit test the project, but chai-spies is not currently being used. Go ahead and use npm to remove the chai-spies from the project.

After removing the chai-spies package, you can open the package.json file to confirm that the project's dependencies were correctly updated.

Phase 2: Using npm to update a dependency

This project was created a bit ago, so it'd be a good idea to ensure that the project is using the latest minor and patch versions of each of its dependencies. Go ahead and use npm to update any all of its dependencies.

After updating the project, be sure to run the start and test scripts again to check that everything still works as expected.

What we've learned

In this project, you

cloned an existing project from a GitHub repository;
used npm to install the project's dependencies;
ran each of the project's npm scripts;
used npm to remove a dependency;
and used npm to update a dependency.