Understanding Git Commands: Merge, Rebase, and Squash

Introduction

• Common confusion about using git merge, git rebase, or squashing commits.
• Importance of understanding these commands in Git workflows.
• Focus: Key differences and appropriate usage.

Workflow Scenario

• Creating a Feature Branch:
  • Started from the main branch.
  • New commits on feature branch: A, B, C.
  • Concurrent commits on main branch: D, E.
  • Visualize branches as growing tree branches.

Keeping Feature Branch Up to Date

Options: git merge vs git rebase

• git merge:
  • Pulls in the latest changes from main.
  • Creates a new "merge commit".
  • Analogy: Tying branches together with a knot.
• git rebase:
  • Changes base of feature branch to latest main commit.
  • Replays changes from the feature branch.
  • Provides a cleaner, linear commit history.

Merging Feature Branch Back to Main

Options:

1. Git Merge:
   • Creates a merge commit tying histories together.
   • Can lead to a messy history with many knots.
2. Git Rebase and Fast-Forward Merge:
   • Moves feature branch changes to the tip of main.
   • Allows for a fast-forward merge, resulting in a straightened history.

Squashing Commits

• Definition:
  • Combines all feature branch commits into a single commit when merging into main.
• Benefits:
  • Maintains a linear history in the main branch.
  • Creates a single merge commit.
• Drawbacks:
  • Loses detailed history of individual feature commits in main branch.
• Usage:
  • Commonly used in platforms like GitHub for tidying up commit history.

Summary of Key Points

• git merge:
  • Complete picture of commit history and branch evolution.
• git rebase:
  • Tidies up history by moving commits to the tip of the main branch.
• Squashing Commits:
  • Consolidates commits for a clean, linear history, sacrificing fine details.

Conclusion

• Choosing between strategies depends on team preferences for history clarity versus detailed commit records.
• No one-size-fits-all; evaluate pros and cons based on team values.

Discussion Prompt

• Have you used these strategies? Which do you prefer and why?