Why hooks automate workflows in Git - Test Your Understanding

Practice - 5 Tasks

1fill in blank

easy

Complete the code to create a Git hook script that runs before a commit.

Git

#!/bin/sh

[1]

Drag options to blanks, or click blank then click option'

Agit status

Becho "Pre-commit hook running"

Cgit push origin main

Dgit commit -m "message"

Attempts:

3 left

💡 Hint

Common Mistakes

Trying to run git commands inside the hook without context

Not using echo to show output

This script prints a message before a commit is made, showing the hook runs automatically.

2fill in blank

medium

Complete the code to make a pre-push hook that prevents pushing if tests fail.

Git

#!/bin/sh

if ! [1]; then
  echo "Tests failed, push aborted."
  exit 1
fi

Drag options to blanks, or click blank then click option'

Agit status

Bls -l

Cecho 'Running tests'

Dmake test

Attempts:

3 left

💡 Hint

Common Mistakes

Using commands that don't test code

Not checking command success with if !

The hook runs tests using 'make test'. If tests fail, it stops the push.

3fill in blank

hard

Fix the error in this commit-msg hook that rejects empty commit messages.

Git

#!/bin/sh

if [ -z "$(cat [1])" ]; then
  echo "Empty commit message not allowed."
  exit 1
fi

Drag options to blanks, or click blank then click option'

Acommit-msg

Bmessage.txt

C$1

DCOMMIT_MSG

Attempts:

3 left

💡 Hint

Common Mistakes

Hardcoding file names

Not using $1 to get the commit message file

The commit message file path is passed as the first argument ($1) to the hook script.

4fill in blank

hard

Fill both blanks to create a post-commit hook that logs the commit hash.

Git

#!/bin/sh

commit_hash=$(git [1] -1 --format=%H)
echo "Commit [2]: $commit_hash" >> commit_log.txt

Drag options to blanks, or click blank then click option'

Alog

Bstatus

Chash

Dcommit

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong git commands

Incorrect echo message content

'git log -1 --format=%H' gets the latest commit hash. The script logs it with a message.

5fill in blank

hard

Fill all three blanks to create a pre-receive hook that rejects pushes to the main branch.

Git

#!/bin/sh

while read oldrev newrev refname; do
  if [ "$refname" = [1] ]; then
    echo "Pushes to [2] are not allowed."
    exit [3]
  fi
 done

Drag options to blanks, or click blank then click option'

A"refs/heads/main"

B"main"

C1

D0

Attempts:

3 left

💡 Hint

Common Mistakes

Using just 'main' for refname check

Using exit 0 which allows push

The hook checks if the refname equals 'refs/heads/main' and rejects the push with exit code 1.

Practice

1. What is the main purpose of Git hooks in a project?

easy

A. To create new branches automatically

B. To store large files outside the repository

C. To merge branches without conflicts

D. To automatically run scripts during Git actions

Solution

1. Step 1: Understand what Git hooks do

   Git hooks are scripts that run automatically when certain Git events happen, like committing or pushing.

2. Step 2: Identify the main purpose

   The main purpose is to automate tasks during Git actions, such as checks or notifications.

3. Final Answer:

   To automatically run scripts during Git actions -> Option D

4. Quick Check:

   Git hooks automate scripts = A [OK]

Hint: Hooks run scripts automatically on Git events [OK]

Common Mistakes:

• Confusing hooks with branch management
• Thinking hooks store files
• Assuming hooks merge branches

2. Which of the following is the correct way to enable a Git hook script?

easy

A. Push the script to the remote repository

B. Add the script to the .gitignore file

C. Rename the script to remove the .sample extension in .git/hooks/

D. Create a new branch named hooks

Solution

1. Step 1: Locate Git hooks directory

   Git hooks are stored in the .git/hooks/ folder, usually with .sample extensions.

2. Step 2: Enable a hook script

   To enable a hook, you rename the script to remove the .sample extension so Git can run it.

3. Final Answer:

   Rename the script to remove the .sample extension in .git/hooks/ -> Option C

4. Quick Check:

   Remove .sample to enable hook = C [OK]

Hint: Remove .sample extension to activate hook scripts [OK]

Common Mistakes:

• Adding hooks to .gitignore disables them
• Pushing hooks doesn't enable them locally
• Creating branches does not enable hooks

3. Given a pre-commit hook script that checks for TODO comments and rejects the commit if found, what will happen if you try to commit a file containing 'TODO: fix this'?

medium

A. The commit will be rejected with a warning about TODO comments

B. The commit will delete the TODO comments automatically

C. The commit will succeed but add a warning in the commit message

D. The commit will succeed without any message

Solution

1. Step 1: Understand the pre-commit hook behavior

   The pre-commit hook runs before the commit is finalized and can reject commits based on conditions.

2. Step 2: Analyze the effect of TODO comments

   If the script finds 'TODO' comments, it rejects the commit and shows a warning message.

3. Final Answer:

   The commit will be rejected with a warning about TODO comments -> Option A

4. Quick Check:

   Pre-commit rejects TODO commits = D [OK]

Hint: Pre-commit hooks can block commits with errors [OK]

Common Mistakes:

• Assuming commit succeeds silently
• Thinking commit adds warnings instead of blocking
• Believing hooks modify code automatically

4. You wrote a post-commit hook script but it does not run after commits. What is the most likely reason?

medium

A. The script is named post-commit.sample

B. All of the above

C. The script file is missing execute permissions

D. The script is located outside the .git/hooks directory

Solution

1. Step 1: Check script permissions

   Git requires hook scripts to have execute permissions to run.

2. Step 2: Check script name and location

   The script must be named exactly (no .sample) and be inside .git/hooks/ folder.

3. Step 3: Combine all issues

   Any of these issues (wrong name, wrong location, no execute permission) will prevent the hook from running.

4. Final Answer:

   All of the above -> Option B

5. Quick Check:

   Permissions, name, location all matter = D [OK]

Hint: Check permissions, name, and location for hooks [OK]

Common Mistakes:

• Ignoring execute permissions
• Leaving .sample extension
• Placing script outside hooks folder

5. You want to automate sending a notification email after every successful push to the remote repository. Which Git hook should you use and why?

hard

A. post-push hook, because it runs after the push completes successfully

B. pre-push hook, because it runs before pushing and can stop the push

C. post-commit hook, because it runs after each commit locally

D. pre-commit hook, because it runs before committing changes

Solution

1. Step 1: Identify when to send notification

   The notification should be sent after a successful push to the remote repository.

2. Step 2: Understand available hooks

   Git does not have a built-in post-push hook, but the server-side post-receive hook runs after a successful push on the remote repository.

3. Step 3: Choose the best hook

   To send notification after a successful push, use the server-side post-receive hook, which runs after the push completes successfully.

4. Final Answer:

   post-push hook, because it runs after the push completes successfully -> Option A

5. Quick Check:

   Use post-push (server-side post-receive) for notifications after push = A [OK]

Hint: Use post-receive hook on server to notify after push [OK]

Common Mistakes:

• Assuming post-push hook exists locally in Git
• Using pre-push which runs before push
• Using post-commit which runs too early