lab 22 Creating a Branch

Goals

Learn how to create a local branch in a repository

It’s time to do a major rewrite of the hello world functionality. Since this might take awhile, you’ll want to put these changes into a separate branch to isolate them from changes in main.

Create a Branch

Let’s call our new branch ‘greet’.

Execute:

git checkout -b greet
git status

NOTE: git checkout -b <branchname> is a shortcut for git branch <branchname> followed by a git checkout <branchname>.

Notice that the git status command reports that you are on the ‘greet’ branch.

Changes for Greet: Add a Greeter class.

lib/greeter.js

class Greeter {
  constructor(who) {
    this.who = who;
  }

  greet() {
    return `Hello, ${this.who}`;
  }
}

module.exports.Greeter = Greeter;

Execute:

git add lib/greeter.js
git commit -m "Added greeter class"

Changes for Greet: Modify the main program

Update the hello.js file to use greeter

lib/hello.js

const { Greeter } = require('./greeter');

// Default is World
const name = process.argv[2] || "World"

const greeter = new Greeter(name);
console.log(greeter.greet());

Execute:

git add lib/hello.js
git commit -m "Hello uses Greeter"

Changes for Greet: Update the package.json

Update the package.json to pass a name argument to our program

package.json

{
  "name": "greeter",
  "version": "1.0.0",
  "description": "Greet users from the command line",
  "scripts": {
    "start": "node lib/start.js 'Halle Bot'"
  }
}

Execute:

git add package.json
git commit -m "Updated package"

Up Next

We now have a new branch called greet with 3 new commits on it. Next we will learn how to navigate and switch between branches.