Automated testing on push in Git - Practice Problems & Coding Challenges

Challenge - 5 Problems

💻 Command Output

intermediate

What is the output of this Git hook command?

You have a pre-push Git hook script that runs tests before pushing. The script contains:

#!/bin/sh
npm test

If the tests fail, what will be the output of git push?

Git

#!/bin/sh
npm test

A Push is aborted and error messages from tests are shown.

B Push succeeds regardless of test results.

C Git shows a warning but pushes anyway.

D Push is delayed until tests pass manually.

💡 Hint

Git hooks can stop push if the script exits with an error.

The pre-push hook runs before pushing. If npm test fails (non-zero exit), the push is stopped and test errors are shown.

🧠 Conceptual

intermediate

Why use automated tests on push in Git workflows?

Which of these is the main reason to run automated tests on every push?

A To ensure code quality and catch errors early before integration.

B To slow down the development process intentionally.

C To avoid writing tests locally by developers.

D To automatically merge branches without review.

💡 Hint

Think about preventing broken code from entering shared branches.

Running tests on push helps catch bugs early and keeps the shared codebase stable.

❓ Configuration

advanced

Which Git hook file should you create to run tests automatically before pushing?

You want to run a test script automatically every time you push code. Which file should you create or edit inside the .git/hooks directory?

A post-commit

B post-push

C pre-push

D pre-commit

💡 Hint

The hook runs right before pushing to remote.

The pre-push hook runs before pushing and can block the push if tests fail.

❓ Troubleshoot

advanced

Why does my pre-push hook not stop the push even if tests fail?

You wrote a pre-push hook script to run tests, but even when tests fail, the push still succeeds. What is the most likely cause?

A The remote repository ignores hooks.

B The hook script does not exit with a non-zero status on test failure.

C Git does not support pre-push hooks.

D Tests are not run because the script is named incorrectly.

💡 Hint

Git stops push only if the hook exits with an error code.

If the script always exits with zero, Git assumes success and pushes regardless of test results.

🔀 Workflow

expert

Order the steps in a Git workflow with automated testing on push

Arrange these steps in the correct order when using automated tests triggered by a Git pre-push hook.

A 1,2,4,3

B 2,1,3,4

C 1,3,2,4

D 1,2,3,4

💡 Hint

Think about the natural flow from coding to pushing with tests in between.

First code is written, then Git triggers pre-push hook, which runs tests, and if tests pass, push proceeds.

Practice

1. What is the main purpose of automated testing on push in Git workflows?

easy

A. To run tests automatically when code is pushed to catch errors early

B. To manually review code before merging

C. To delete old branches after pushing

D. To speed up the push command execution

Solution

1. Step 1: Understand automated testing on push

   Automated testing on push means tests run automatically when code is pushed to a repository.

2. Step 2: Identify the main benefit

   This helps catch errors early and keeps the project stable by preventing broken code from merging.

3. Final Answer:

   To run tests automatically when code is pushed to catch errors early -> Option A

4. Quick Check:

   Automated testing on push = run tests automatically [OK]

Hint: Automated testing runs tests on push to catch bugs early [OK]

Common Mistakes:

• Thinking it speeds up git push command
• Confusing with manual code review
• Assuming it deletes branches automatically

2. Which file is commonly used to configure automated tests to run on push in a GitHub repository?

easy

A. package.json

B. README.md

C. .gitignore

D. .github/workflows/ci.yml

Solution

1. Step 1: Identify configuration file for GitHub Actions

   GitHub Actions uses YAML files inside the .github/workflows directory to define workflows.

2. Step 2: Match file to automated testing on push

   The file .github/workflows/ci.yml typically contains instructions to run tests on push events.

3. Final Answer:

   .github/workflows/ci.yml -> Option D

4. Quick Check:

   GitHub Actions config = .github/workflows/ci.yml [OK]

Hint: GitHub Actions workflows live in .github/workflows/ [OK]

Common Mistakes:

• Choosing .gitignore which ignores files
• Selecting README.md which is documentation
• Picking package.json which is for Node.js dependencies

3. Given this GitHub Actions workflow snippet, what happens when you push code to the main branch?

name: CI
on:
  push:
    branches: [main]
jobs:
  test:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v3
      - name: Run tests
        run: echo "Tests passed!"

medium

A. The workflow fails because 'run' command is invalid

B. The workflow runs only on pull requests, not on push

C. The workflow runs and prints 'Tests passed!' on every push to main

D. Nothing happens because branches is empty

Solution

1. Step 1: Analyze the trigger event

   The workflow triggers on push events to the 'main' branch as specified under 'on: push: branches: [main]'.

2. Step 2: Check the job steps

   The job runs on ubuntu-latest, checks out the code, then runs the command echo "Tests passed!" which prints that message.

3. Final Answer:

   The workflow runs and prints 'Tests passed!' on every push to main -> Option C

4. Quick Check:

   Push to main triggers workflow = prints message [OK]

Hint: Push to main triggers workflow with echo command [OK]

Common Mistakes:

• Thinking it runs only on pull requests
• Assuming 'run' command is invalid syntax
• Believing branches list is empty

4. You wrote this GitHub Actions workflow to run tests on push but it never runs:

name: Test
on:
  push:
    branch: main
jobs:
  test:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v3
      - run: echo "Running tests"

What is the error?

medium

A. The 'run' command must be inside a 'steps' array

B. The key 'branch' should be 'branches' under 'push' to specify branches list

C. The 'uses' action 'actions/checkout@v3' is deprecated

D. The 'runs-on' value 'ubuntu-latest' is invalid

Solution

1. Step 1: Check the event trigger syntax

   The workflow uses 'branch' instead of 'branches' under 'push'. The correct key is 'branches' which expects a list.

2. Step 2: Understand impact of wrong key

   Because 'branch' is invalid, the workflow never triggers on any push event.

3. Final Answer:

   The key 'branch' should be 'branches' under 'push' to specify branches list -> Option B

4. Quick Check:

   Correct key is 'branches' not 'branch' [OK]

Hint: Use 'branches' (plural) under push, not 'branch' [OK]

Common Mistakes:

• Confusing 'branch' with 'branches'
• Thinking 'runs-on' value is wrong
• Assuming checkout action is deprecated

5. You want to run automated tests only when code is pushed to either the 'main' or 'develop' branches. Which is the correct snippet to add in your GitHub Actions workflow YAML to trigger on these pushes?

hard

A. on:
push:
branches:
- main
- develop

B. on:
push:
branch: ['main', 'develop']

C. on:
push:
branch: 'main, develop'

D. on:
push:
refs: ['main', 'develop']

Solution

1. Step 1: Understand correct YAML syntax for branches

   The 'branches' key expects a list of branch names, each on its own line or in a list format.

2. Step 2: Compare options

   on: push: branch: ['main', 'develop'] uses incorrect singular 'branch' key instead of plural 'branches'. on: push: branches: - main - develop uses the correct 'branches' key with standard YAML list format using dashes, which is widely used.

3. Step 3: Identify invalid options

   on: push: branch: 'main, develop' uses 'branch' (wrong key) and a string with comma, which is invalid. on: push: refs: ['main', 'develop'] uses 'refs' which is not the correct key for branches under push.

4. Final Answer:

   on: push: branches: - main - develop -> Option A

5. Quick Check:

   Use 'branches' with list syntax for multiple branches [OK]

Hint: Use 'branches:' with dash list for multiple branches [OK]

Common Mistakes:

• Using 'branch' instead of 'branches'
• Passing branches as a comma string
• Using 'refs' instead of 'branches'