Amending the last commit in Git - Mini Project: Build & Apply

Amending the Last Commit in Git

📖 Scenario: You are working on a project and just made a commit with a small mistake in the commit message. You want to fix this mistake without creating a new commit.

🎯 Goal: Learn how to amend the last commit message using Git commands.

📋 What You'll Learn

Create a file named example.txt with specific content

Add the file to the Git staging area

Make an initial commit with a given message

Amend the last commit message to the correct one

Display the final commit message to verify the change

💡 Why This Matters

🌍 Real World

Fixing mistakes in commit messages is common when working on software projects to keep history clean and understandable.

💼 Career

Knowing how to amend commits helps developers maintain clear project history and collaborate effectively in teams.

1

Create a file and add content

Create a file named example.txt and add the text Hello, Git! inside it.

Git

# Create the file example.txt with the text 'Hello, Git!'
# Your code here

Hint

Use the echo command to write text into a file.

2

Add the file to Git staging area

Initialize a new Git repository and add the file example.txt to the Git staging area using the git init and git add commands.

Git

echo "Hello, Git!" > example.txt
# Add example.txt to the Git staging area
# Your code here

Hint

Use git init followed by git add example.txt to initialize the repository and stage the file.

3

Make the initial commit

Make an initial commit with the message Initial commit with typo using git commit -m.

Git

echo "Hello, Git!" > example.txt
git init
git add example.txt
# Commit with message 'Initial commit with typo'
# Your code here

Hint

Use git commit -m "Initial commit with typo" to commit.

4

Amend the last commit message

Amend the last commit message to Initial commit with correct message using the git commit --amend -m command. Then, display the last commit message using git log -1 --pretty=%B.

Git

echo "Hello, Git!" > example.txt
git init
git add example.txt
git commit -m "Initial commit with typo"
# Amend the last commit message
# Your code here

Hint

Use git commit --amend -m "New message" to change the last commit message.

Use git log -1 --pretty=%B to show the last commit message.

Practice

1. What does the git commit --amend command do?

easy

A. It modifies the last commit by changing its message or content.

B. It deletes the last commit permanently.

C. It creates a new commit without changing previous commits.

D. It resets the repository to the initial commit.

Solution

1. Step 1: Understand the purpose of git commit --amend

   This command is used to change the last commit, either by editing its message or adding new changes.

2. Step 2: Compare with other options

   Deleting commits or resetting the repository are different commands like git reset. Creating a new commit does not amend the last one.

3. Final Answer:

   It modifies the last commit by changing its message or content. -> Option A

4. Quick Check:

   Amend last commit = modify last commit [OK]

Hint: Amend changes last commit, not create or delete [OK]

Common Mistakes:

• Thinking it deletes the last commit
• Confusing amend with creating a new commit
• Assuming it resets the whole repo

2. Which of the following is the correct syntax to amend the last commit message in Git?

easy

A. git commit -amend "New message"

B. git amend commit -m "New message"

C. git commit --amend -m "New message"

D. git commit --edit-message "New message"

Solution

1. Step 1: Recall the correct syntax for amending commit message

   The correct command is git commit --amend -m "New message" to directly change the last commit message.

2. Step 2: Identify incorrect syntax

   Options B, C, and D use invalid flags or wrong order, which Git does not recognize.

3. Final Answer:

   git commit --amend -m "New message" -> Option C

4. Quick Check:

   Correct amend syntax = git commit --amend -m [OK]

Hint: Use --amend before -m to change message [OK]

Common Mistakes:

• Swapping order of flags
• Using non-existent flags like --edit-message
• Typing 'amend' as a separate command

3. Given the following commands executed in order:

echo "Hello" > file.txt
 git add file.txt
 git commit -m "Add file"
 echo "World" >> file.txt
 git add file.txt
 git commit --amend -m "Add file with content update"

What will git log -1 --pretty=%B output?

medium

A. Add file

B. Add file with content update

C. Add file
Add file with content update

D. No commit message

Solution

1. Step 1: Understand the commit history after commands

   First commit message is "Add file". Then file.txt is updated and staged. The git commit --amend replaces the last commit message with "Add file with content update".

2. Step 2: Check the latest commit message output

   The git log -1 --pretty=%B shows the last commit message, which is now "Add file with content update" after amend.

3. Final Answer:

   Add file with content update -> Option B

4. Quick Check:

   Amended commit message = updated message [OK]

Hint: Amend replaces last commit message and content [OK]

Common Mistakes:

• Thinking amend adds a new commit instead of replacing
• Expecting both messages to appear
• Assuming commit message stays unchanged

4. You ran git commit --amend but accidentally removed some changes from the last commit. How can you fix this?

medium

A. Delete the repository and clone again.

B. Run git commit --amend again without changes.

C. Use git push --force to overwrite remote.

D. Use git reflog to find the previous commit and reset to it.

Solution

1. Step 1: Understand the problem with amend

   Amending rewrites the last commit, so if changes were lost, the previous commit state is still in Git history.

2. Step 2: Use git reflog to recover

   git reflog shows recent commit states. You can find the commit before amend and reset to it to restore lost changes.

3. Final Answer:

   Use git reflog to find the previous commit and reset to it. -> Option D

4. Quick Check:

   Recover lost commit with reflog [OK]

Hint: Use reflog to recover lost commits after amend [OK]

Common Mistakes:

• Trying to fix by amending again without changes
• Deleting repo instead of recovering
• Forcing push without fixing local history

5. You committed a file with a typo in the message and forgot to add a new file. Which sequence correctly fixes both issues using amend?

hard

A. Add the new file, then run git commit --amend -m "Corrected message"

B. Run git commit --amend -m "Corrected message" first, then add the new file

C. Delete the last commit, add the new file, then commit again

D. Push the commit, then fix the message and add file in a new commit

Solution

1. Step 1: Stage the new file before amending

   To include the new file in the last commit, you must add it first with git add.

2. Step 2: Amend the commit with the corrected message

   Run git commit --amend -m "Corrected message" to update the commit message and include the staged new file.

3. Final Answer:

   Add the new file, then run git commit --amend -m "Corrected message" -> Option A

4. Quick Check:

   Stage files before amend to include them [OK]

Hint: Add files first, then amend commit message [OK]

Common Mistakes:

• Amending before adding new files
• Deleting commits unnecessarily
• Pushing before fixing local commit