Reordering commits in Git - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the purpose of reordering commits in Git?

Reordering commits helps to organize the commit history for clarity, fix mistakes, or group related changes before sharing code.

beginner

Which Git command is used to start an interactive rebase for reordering commits?

The command git rebase -i HEAD~N starts an interactive rebase for the last N commits, allowing you to reorder them.

beginner

In the interactive rebase editor, how do you change the order of commits?

You change the order by moving the lines representing commits up or down in the editor before saving and closing it.

beginner

What does the word 'pick' mean in the interactive rebase list?

'pick' means to keep the commit as is in the new order during the rebase process.

intermediate

What should you do if you encounter conflicts during a rebase?

You should fix the conflicts manually, then run git rebase --continue to proceed with the rebase.

Which command starts an interactive rebase to reorder the last 3 commits?

A git rebase --order 3

B git reorder 3

C git commit --reorder 3

D git rebase -i HEAD~3

The correct command is git rebase -i HEAD~3 to interactively rebase the last 3 commits.

In the interactive rebase editor, how do you reorder commits?

A By changing the order of lines representing commits

B By typing new commit messages

C By deleting commits from the list

D By running git reorder command

You reorder commits by moving the lines up or down in the editor before saving.

What does the 'pick' command do in interactive rebase?

A Splits the commit

B Deletes the commit

C Keeps the commit as is

D Squashes the commit

'pick' means to keep the commit unchanged in the new order.

If a conflict happens during rebase, what is the next step?

A Fix conflicts and run git rebase --continue

B Abort the rebase immediately

C Run git commit --fix

D Restart the computer

You fix conflicts manually and then continue the rebase with git rebase --continue.

Why might you want to reorder commits before sharing your code?

A To delete all commits

B To make the commit history clearer and logical

C To speed up the computer

D To change the branch name

Reordering commits helps make the history easier to understand and review.

Explain the steps to reorder the last 4 commits in Git using interactive rebase.

Think about starting the rebase, editing commit order, and finishing the process.

Describe what happens if you reorder commits and encounter a conflict during the process.

Focus on how Git handles conflicts and how you resolve them.

Practice

1. What is the main purpose of using git rebase -i when working with commits?

easy

A. To create a new branch from the current commit

B. To reorder, edit, or squash commits interactively

C. To merge two branches automatically

D. To delete the entire commit history

Solution

1. Step 1: Understand the function of git rebase -i

   This command opens an interactive editor allowing you to reorder, edit, or squash commits.

2. Step 2: Compare with other options

   Creating branches, merging, or deleting history are not the main purposes of this command.

3. Final Answer:

   To reorder, edit, or squash commits interactively -> Option B

4. Quick Check:

   Interactive rebase = reorder commits [OK]

Hint: Use interactive rebase to reorder commits easily [OK]

Common Mistakes:

• Confusing rebase with branch creation
• Thinking rebase deletes history
• Mixing rebase with merge commands

2. Which of the following is the correct command to start an interactive rebase for the last 3 commits?

easy

A. git rebase -i HEAD~3

B. git rebase -i HEAD^3

C. git rebase -i HEAD~

D. git rebase -i HEAD^^3

Solution

1. Step 1: Recall the syntax for interactive rebase

   The correct syntax uses HEAD~N to specify the last N commits, so HEAD~3 means last 3 commits.

2. Step 2: Check other options for syntax errors

   HEAD^3 and HEAD^^3 are invalid for this purpose; HEAD~ is incomplete.

3. Final Answer:

   git rebase -i HEAD~3 -> Option A

4. Quick Check:

   Use HEAD~N for last N commits [OK]

Hint: Use HEAD~N to specify last N commits in rebase [OK]

Common Mistakes:

• Using caret (^) incorrectly for commit range
• Omitting the number after ~
• Confusing HEAD~ with HEAD^

3. Given the following interactive rebase todo list:

pick a1b2c3 Commit A
pick d4e5f6 Commit B
pick 789abc Commit C

If you change it to:

pick d4e5f6 Commit B
pick a1b2c3 Commit A
pick 789abc Commit C

What will be the order of commits after the rebase?

medium

A. Commit B, Commit A, Commit C

B. Commit A, Commit B, Commit C

C. Commit C, Commit B, Commit A

D. Commit A, Commit C, Commit B

Solution

1. Step 1: Understand the todo list order

   The interactive rebase applies commits in the order listed. Changing the order changes commit history order.

2. Step 2: Apply the new order

   New order is Commit B, then Commit A, then Commit C.

3. Final Answer:

   Commit B, Commit A, Commit C -> Option A

4. Quick Check:

   Rebase applies commits in listed order [OK]

Hint: Order commits in todo list to reorder history [OK]

Common Mistakes:

• Assuming original order stays after rebase
• Confusing commit hashes with order
• Ignoring the todo list sequence

4. You ran git rebase -i HEAD~3 and changed the order of commits, but Git shows a conflict error. What is the best way to fix this?

medium

A. Force push the branch without resolving conflicts

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

C. Delete the .git folder and start over

D. Manually resolve conflicts, then run git rebase --continue

Solution

1. Step 1: Understand rebase conflict handling

   When conflicts occur during rebase, you must manually fix them in files.

2. Step 2: Continue rebase after resolving conflicts

   After fixing conflicts, run git rebase --continue to proceed.

3. Final Answer:

   Manually resolve conflicts, then run git rebase --continue -> Option D

4. Quick Check:

   Fix conflicts + git rebase --continue [OK]

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

Common Mistakes:

• Ignoring conflicts and force pushing
• Aborting rebase without trying to fix
• Deleting .git folder which loses repo data

5. You want to reorder the last 4 commits to put the oldest commit last without changing their content. Which sequence of commands correctly achieves this?

hard

A. Run git reset --hard HEAD~4 then cherry-pick commits in new order

B. Run git merge --reorder HEAD~4 to reorder commits automatically

C. Run git rebase -i HEAD~4, then move the first commit line to the bottom in the editor

D. Run git rebase -i HEAD~3 and swap the last two commits

Solution

1. Step 1: Use interactive rebase on last 4 commits

   Running git rebase -i HEAD~4 opens the last 4 commits for editing order.

2. Step 2: Move the oldest commit line to the bottom

   In the editor, reorder lines so the oldest commit is last, preserving content.

3. Final Answer:

   Run git rebase -i HEAD~4, then move the first commit line to the bottom in the editor -> Option C

4. Quick Check:

   Interactive rebase + reorder lines = reorder commits [OK]

Hint: Use interactive rebase and reorder lines to change commit order [OK]

Common Mistakes:

• Using reset which loses commit history
• Trying non-existent git merge --reorder command
• Using wrong commit range in rebase