Why Squashing commits in Git? - Purpose & Use Cases

The Big Idea

Discover how one simple step can turn your messy commit history into a story everyone loves to read!

The Scenario

Imagine you have made many small changes in your project and committed each one separately. Now you want to share your work with your team, but the commit history is messy and hard to follow.

The Problem

Manually cleaning up commit history means rewriting each commit one by one, which is slow and confusing. It's easy to make mistakes, lose important changes, or confuse others reviewing your work.

The Solution

Squashing commits lets you combine many small commits into one clear, meaningful commit. This makes your project history neat and easy to understand without losing any work.

Before vs After

✗ Before

git commit -m "fix typo"
git commit -m "update README"
git commit -m "add tests"

✓ After

git rebase -i HEAD~3  # then squash commits into one

What It Enables

It enables a clean, simple project history that everyone can easily read and trust.

Real Life Example

A developer finishes a feature with many small fixes and uses squashing to create one clear commit before merging to the main project branch.

Key Takeaways

Manual commit history can be messy and confusing.

Squashing combines multiple commits into one clean commit.

This makes project history easier to read and maintain.

Practice

1. What is the main purpose of squashing commits in Git?

easy

A. To revert the last commit without changing history

B. To combine multiple commits into one for a cleaner history

C. To create a new branch from the current commit

D. To delete all commits from the repository

Solution

1. Step 1: Understand commit history management

   Squashing is used to combine several commits into a single commit to simplify the commit history.

2. Step 2: Identify the purpose of squashing

   This helps keep the project history clean and easier to read by reducing clutter from many small commits.

3. Final Answer:

   To combine multiple commits into one for a cleaner history -> Option B

4. Quick Check:

   Squashing = combine commits [OK]

Hint: Squash = combine commits to clean history [OK]

Common Mistakes:

• Thinking squashing deletes commits permanently
• Confusing squashing with branching
• Believing squashing reverts commits

2. Which Git command starts an interactive rebase to squash commits?

easy

A. git commit --squash HEAD~3

B. git merge -i HEAD~3

C. git rebase -i HEAD~3

D. git reset --soft HEAD~3

Solution

1. Step 1: Identify the command for interactive rebase

   The command to start an interactive rebase is git rebase -i followed by the commit range.

2. Step 2: Confirm the correct syntax

   git rebase -i HEAD~3 opens the last 3 commits for editing, allowing squashing.

3. Final Answer:

   git rebase -i HEAD~3 -> Option C

4. Quick Check:

   Interactive rebase = git rebase -i [OK]

Hint: Use git rebase -i to start squashing commits [OK]

Common Mistakes:

• Using git merge -i which does not exist
• Trying git commit --squash which is invalid
• Confusing reset with rebase for squashing

3. Given these commits:

commit1: Add README
commit2: Fix typo
commit3: Update README formatting

If you run git rebase -i HEAD~3 and squash commit2 and commit3 into commit1, what will the commit history show?

medium

A. One commit combining messages from commit1, commit2, and commit3

B. Three separate commits unchanged

C. One commit with message from commit1 only

D. Two commits: commit1 and combined commit2+commit3

Solution

1. Step 1: Understand squash behavior in interactive rebase

   Squashing merges commits into one, combining their changes and commit messages.

2. Step 2: Result of squashing commit2 and commit3 into commit1

   The final commit will include all changes and combined commit messages from all three commits.

3. Final Answer:

   One commit combining messages from commit1, commit2, and commit3 -> Option A

4. Quick Check:

   Squash merges commits and messages [OK]

Hint: Squash merges commits and their messages together [OK]

Common Mistakes:

• Assuming only the first commit message remains
• Expecting commits to stay separate after squash
• Thinking squash deletes commit messages

4. You ran git rebase -i HEAD~4 to squash commits but got a conflict error. What should you do next?

medium

A. Manually fix the conflicts, then run git rebase --continue

B. Abort the rebase with git rebase --abort and try again

C. Run git reset --hard to discard all changes

D. Push your changes immediately to remote to fix conflicts

Solution

1. Step 1: Understand conflict during rebase

   A conflict means Git needs you to fix code differences manually before continuing.

2. Step 2: Resolve conflicts and continue rebase

   Fix the conflicts in files, then run git rebase --continue to proceed with squashing.

3. Final Answer:

   Manually fix the conflicts, then run git rebase --continue -> Option A

4. Quick Check:

   Fix conflicts + git rebase --continue [OK]

Hint: Fix conflicts manually then git rebase --continue [OK]

Common Mistakes:

• Aborting rebase without trying to fix conflicts
• Using git reset --hard which discards work
• Pushing incomplete changes to remote

5. You squashed commits locally and want to update the remote branch. What is the correct command to push your changes safely?

hard

A. git push --all origin

B. git push origin main

C. git push --no-verify origin main

D. git push --force-with-lease origin main

Solution

1. Step 1: Understand effect of squashing on commit history

   Squashing rewrites commit history, so the remote branch history differs from local.

2. Step 2: Use force push safely

   To update remote with rewritten history, use git push --force-with-lease to avoid overwriting others' work accidentally.

3. Final Answer:

   git push --force-with-lease origin main -> Option D

4. Quick Check:

   Force push safely after squash [OK]

Hint: Use git push --force-with-lease after squash [OK]

Common Mistakes:

• Using normal git push causing rejection
• Using --no-verify which skips hooks but not force push
• Pushing all branches unnecessarily