Git Review

Learning Goals

• Create a new git repository.
• Check out new branches to implement pieces of functionality.
• Add and commit files from the command line.
• Push branches to GitHub
• Merge branches on GitHub
• Pull master from GitHub

Walkthrough

Iteration 1.0

In this stage, we want to create a new project locally, create a repository on GitHub and then link the two of them together.

Iteration 1.1: Create a New Project Locally

On your own computer walk through the following steps in your terminal.

1. cd into your Turing Mod 1 directory.
2. If you do not already have a practice directory, create one using mkdir
3. cd into your practice directory.
4. mkdir dog_party
5. cd dog_party
6. mkdir lib
7. mkdir test
8. touch test/dog_test.rb
9. touch lib/dog.rb
10. git init
11. git status
12. git add test/dog_test.rb
13. git add lib/dog.rb
14. git commit -m "Initial commit"

Iteration 1.2: Create a New Project on GitHub

In your browser:

1. Navigate to github.com
2. Click the New repository button
3. Enter dog_party as the name of your new repository
4. Click on Create repository
5. Under ...or push an existing repository from the command line, click on the icon to copy the text commands to your clipboard

Iteration 1.3: Connect Your Local Repository to Your Remote

Back in your terminal:

1. Paste the commands that you’ve copied
2. Hit enter if the last command doesn’t run

Iteration 2.0

Here we want to actually add some content to our project. First we’ll check out a branch, then do some work, commit, push to GitHub, merge to master, and then pull down so that we have our work on our local master branch.

Iteration 2.1: Create a Branch

Still in the Terminal:

1. git branch -a
2. git branch create_dog_class
3. git branch -a
4. git checkout create_dog_class
5. git status

Iteration 2.2: Create a Test

From the Terminal:

1. atom ./

In Atom:

1. Copy the code below into your test file.

require 'minitest/test'
require 'minitest/autorun'
require 'minitest/pride'
require './lib/dog'

class DogTest < Minitest::Test

  def test_it_exists
    dog = Dog.new("Fido", 2, "Dalmation")

    assert_instance_of Dog, dog
  end
end

In your terminal:

1. ruby test/dog_test.rb

Iteration 2.3: Commit Our Test

Still in the terminal:

1. git status
2. git add test/dog_test.rb
3. git status
4. git commit -m "Create test for dog class"
5. git status
6. ruby test/dog_test.rb

Iteration 2.4: Make Our Test Pass

Back in Atom:

1. Make the test pass by entering the following code into your ./lib/dog.rb file.

class Dog
  def initialize(name, age, breed)
    @name  = name
    @age   = age
    @breed = breed
  end
end

In your terminal:

1. ruby test/dog_test.rb

Iteration 2.5: Commit Our Work

1. git status
2. git add lib/dog.rb
3. git status
4. git commit -m "Create dog class"
5. git status

Iteration 2.6: Push to GitHub

1. git push origin create_dog_class
2. git status

Iteration 2.7: Merge to Master on GitHub

On GitHub

1. Reload the page that has your dog_party repo (where you copied the command to add the link to your repo)
2. Click on the green button in the yellow box that says ‘Compare & pull request’
3. In the text box that says write above it add the following:

* Create test for dog class with name, age, and breed attributes.
* Create dog class.

1. Review the files that you changed below the text box - it should only include dog.rb and dog_test.rb
2. Click on the green button that says Create pull request
3. Click on the tab that says Files changed
4. Confirm that this only includes your dog.rb and dog_test.rb files and that it includes the code provided in earlier steps
5. Click on the tab that says Conversation
6. Click on the green button that says Merge pull request
7. Click on the green button that says Confirm merge
8. At the top of the page click on the tab that says <> Code
9. Confirm that you are on the master branch in the dropdown 1/3 of the way down the site on the left-hand side
10. Review the code in your lib and test directories on GitHub to confirm that you have successfully pushed and merged your code to master
11. Click on <> Code to return to the main page for your dog_party repository

Iteration 2.8: Get the Code from GitHub Master to Our Local Master

In your terminal:

1. git checkout master

In Atom:

1. Review your code. Your test/dog_test.rb and lib/dog.rb files should both be blank.

In your terminal:

1. git pull origin master

In Atom:

1. Review your code. Your test/dog_test.rb and lib/dog.rb files should both be populated.

Iteration 3.0

Here we’re going to repeat the process from iteration 2.0 to add some more code to our project.

Iteration 3.1: Check Out a New Branch

In your terminal:

1. git status
2. git branch add_attr_readers
3. git checkout add_attr_readers
4. Notice that we pulled to master, but are checking out a new branch before we do any additional work.
5. Additionally, the branch is named for the work we are planning on doing.

Iteration 3.2: Add Tests for Attributes

In Atom:

1. Add the tests below to your existing test/dog_test.rb file (some of the existing code is not repeated here, but referenced for brevity)

# existing require statements

class DogTest < Minitest::Test
  # existing test that Dog exists

  def test_it_has_a_name
    dog = Dog.new("Fido", 2, "Dalmation")

    expected = "Fido"
    actual   = dog.name

    assert_equal expected, actual
  end

  def test_it_has_an_age
    dog = Dog.new("Fido", 2, "Dalmation")

    expected = 2
    actual   = dog.age

    assert_equal expected, actual
  end

  def test_it_has_a_breed
    dog = Dog.new("Fido", 2, "Dalmation")

    expected = "Dalmation"
    actual   = dog.breed

    assert_equal expected, actual
  end
end

In your terminal:

1. ruby test/dog_test.rb

Iteration 3.2: Commit Our Work

Still in the terminal:

1. git status
2. git add test/dog_test.rb
3. git status
4. git commit -m "Create test for attributes"

Iteration 3.3: Add Attributes

In Atom:

1. Add attr_readers to your existing Dog code so that your final Dog class looks like the one below.

class Dog
  attr_reader :name,
              :age,
              :breed

  def initialize(name, age, breed)
    @name  = name
    @age   = age
    @breed = breed
  end
end

Iteration 3.4: Commit Our Work

In your terminal:

1. git status
2. git add lib/dog.rb
3. git status
4. git commit -m "Add attribute methods"

Iteration 3.5: Push Our Branch to GitHub

1. git status
2. git push origin add_attr_readers

Iteration 3.6: Create a Pull Request

On GitHub

1. Click on the green button in the yellow box that says ‘Compare & pull request’
2. In the text box that says write above it add the following:

* Create tests for Dog attributes.
* Add `attr_reader`s to Dog

1. Review the files that you changed below the text box - it should include both dog.rb and dog_test.rb
2. Click on the green button that says Create pull request

Iteration 3.7: Merge Our Pull Request

1. Click on the tab that says Files changed
2. Confirm that this includes your dog.rb and dog_test.rb files and that it includes the code provided in earlier steps
3. Click on the tab that says Conversation
4. Click on the green button that says Merge pull request
5. Click on the green button that says Confirm merge
6. At the top of the page click on the tab that says <> Code
7. Confirm that you are on the master branch in the dropdown 1/3 of the way down the site on the left-hand side
8. Review the code in your lib and test directories on GitHub to confirm that you have successfully pushed and merged your code to master
9. Click on <> Code to return to the main page for your dog_party repository

Iteration 3.8: Pull Our Work to Our Local Master Branch

In your terminal:

1. git status
2. git checkout master
3. git status
4. git pull origin master
5. ruby test/dog_test.rb

Iteration 4.0

Use the examples above to add some additional code to your project:

1. Create and check out a branch called add_bark_method.
2. Add a test for a method called bark that returns the string “Woof!”
3. Commit your test with a commit message that describes the work you did.
4. Add a method called bark to your Dog class.
5. Commit your test with a commit message that describes the work you did.
6. Push your work to GitHub.
7. Merge your work.
8. Check out your master branch locally.
9. Pull your work from GitHub to your local master branch.

Iteration 5.0

Same as before, but add a summary method that returns the string:

Name: Fido
Age: 2
Breed: Dalmation

Don’t use puts!

Questions

• In your own words, what are the high level steps for adding work to your project using a branching workflow?
• How do you decide what to name a branch in Git?
• Why would you work on a branch other than the master branch?
• When you’ve merged a branch to master on GitHub, how do you get that code to your local master branch?