post-merge hook in Git - Practice Problems & Coding Challenges

Challenge - 5 Problems

💻 Command Output

intermediate

Output of a post-merge hook script

Given the following post-merge hook script in a Git repository, what will be the output after a successful merge?

Git

#!/bin/sh

echo "Merge completed on $(date)"

A Merge completed on $(date)

B Merge completed on Thu Jun 1 12:00:00 UTC 2024

C Merge completed on 2024-06-01 12:00:00

D No output

💡 Hint

The date command outputs the current date and time in a default format.

The script uses command substitution $(date) which runs the date command and inserts its output. The default format of date is a full date and time string like 'Thu Jun 1 12:00:00 UTC 2024'.

🧠 Conceptual

intermediate

Purpose of the post-merge hook

What is the primary purpose of the Git post-merge hook?

A To run commands after a successful merge to update the working directory or notify users

B To reset the repository to a previous commit after merging

C To automatically commit changes before merging

D To prevent merges from happening if conflicts exist

💡 Hint

Think about what happens after a merge finishes successfully.

The post-merge hook runs after a successful merge and is typically used to update files, rebuild assets, or notify users about the merge completion.

🔀 Workflow

advanced

Correct placement of a post-merge hook script

Where should you place a custom post-merge hook script in a Git repository to ensure it runs after merges?

A root directory of the repository

B .git/post-merge

C .git/hooks/post-merge

D any directory as long as it is executable

💡 Hint

Git looks for hooks in a specific directory inside the repository.

Git expects hook scripts to be placed inside the .git/hooks directory with the exact hook name and executable permissions.

❓ Troubleshoot

advanced

Why does the post-merge hook not run?

You created a post-merge hook script in .git/hooks/ but it does not run after merges. Which is the most likely reason?

A The merge was done with --no-commit option

B The script is named post-merge.sh instead of post-merge

C The repository is not a Git repository

D The script file is not executable

💡 Hint

Git requires hook scripts to have a specific permission to run.

Git only runs hook scripts if they have executable permissions. Without it, the script is ignored.

✅ Best Practice

expert

Best practice for sharing post-merge hooks across a team

What is the best practice to share a post-merge hook script with all team members in a Git project?

A Store the hook script in the repository and use a setup script to copy it to .git/hooks/

B Commit the hook script directly inside .git/hooks/ directory

C Ask each team member to manually create the hook script locally

D Use a global Git hook directory for all repositories

💡 Hint

Git does not track files inside .git/hooks by default.

Since .git/hooks is not version controlled, the best practice is to store hook scripts in the repository (e.g., in a hooks/ folder) and provide a setup script that copies them to .git/hooks/ for each user.