Merge commit creation in Git - Practice Problems & Coding Challenges

Challenge - 5 Problems

💻 Command Output

intermediate

What is the output of a successful merge commit?

You run git merge feature-branch on your main branch. The merge completes without conflicts and creates a merge commit. What will git log --oneline -1 show as the commit message?

A Revert "feature-branch"

B Initial commit

C Merge branch 'feature-branch'

D Fix typo in README

💡 Hint

Think about the default message git uses when creating a merge commit.

When git creates a merge commit, it automatically generates a commit message like "Merge branch 'feature-branch'" to indicate the source branch merged.

🧠 Conceptual

intermediate

What happens during a merge commit creation?

Which of the following best describes what a merge commit does in git?

A It combines the histories of two branches by creating a new commit with two parents.

B It deletes the source branch after merging.

C It creates a new branch from the current commit.

D It rewrites the commit history of the target branch.

💡 Hint

Think about how git tracks the relationship between branches after merging.

A merge commit has two parent commits, linking the histories of both branches together without deleting or rewriting history.

🔀 Workflow

advanced

Identify the correct git commands to create a merge commit

You want to merge the branch feature into main and create a merge commit even if the merge could be fast-forwarded. Which sequence of commands will do this?

A

git checkout main

git merge feature

B

git checkout main

git merge --no-ff feature

C

git checkout feature

git merge main

D git merge --no-ff main feature

💡 Hint

Remember to be on the target branch before merging and use the option to force a merge commit.

To create a merge commit even if fast-forward is possible, you must be on the target branch and use --no-ff option with git merge.

❓ Troubleshoot

advanced

Why does git refuse to create a merge commit?

You run git merge feature on main, but git fast-forwards instead of creating a merge commit. You want a merge commit. What is the reason?

A Git does not support merge commits.

B The feature branch has conflicts that prevent a merge commit.

C You are not on the main branch when running the merge.

D The feature branch is ahead and main has no new commits, so git fast-forwards by default.

💡 Hint

Think about when git chooses to fast-forward merges.

If the target branch has no new commits since branching, git fast-forwards by default instead of creating a merge commit.

✅ Best Practice

expert

What is the best practice for merge commit messages?

When creating a merge commit manually, which message style is recommended to keep history clear and useful?

A Use the default message like "Merge branch 'feature'" and add a short description of changes.

B Write only the branch name without any description.

C Use a generic message like "Update" for all merges.

D Delete the commit message to keep history clean.

💡 Hint

Think about clarity and usefulness for future readers of the history.

A good merge commit message includes the default merge info plus a short summary of changes for clarity.