107 lines
3.2 KiB
Markdown
107 lines
3.2 KiB
Markdown
# Module 06: Merge Conflicts
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## Learning Objectives
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By the end of this module, you will:
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- Understand what merge conflicts are and why they occur
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- Identify merge conflicts in your repository
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- Read and interpret conflict markers
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- Resolve merge conflicts manually
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- Complete a merge after resolving conflicts
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## Challenge Description
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You have a repository with a main branch and a feature branch called `update-config`. Both branches have modified the same configuration file in different ways, creating a merge conflict.
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Your task is to:
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1. Attempt to merge the `update-config` branch into `main`
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2. Identify and understand the merge conflict
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3. Resolve the conflict by keeping both the timeout setting from `main` AND the debug setting from `update-config`
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4. Complete the merge with an appropriate commit message
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## Key Concepts
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### What Are Merge Conflicts?
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A merge conflict occurs when Git cannot automatically combine changes from two branches because they modify the same part of the same file in different ways. When this happens, Git pauses the merge and asks you to manually resolve the conflict.
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### Conflict Markers
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When a conflict occurs, Git adds special markers to the affected files:
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```
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<<<<<<< HEAD
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Your current branch's changes
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=======
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The incoming branch's changes
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>>>>>>> branch-name
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```
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- `<<<<<<< HEAD`: Marks the beginning of your current branch's version
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- `=======`: Separates the two versions
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- `>>>>>>> branch-name`: Marks the end of the incoming branch's version
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### Resolving Conflicts
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To resolve a conflict:
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1. Open the conflicted file in your editor
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2. Look for the conflict markers
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3. Decide which changes to keep (you can keep one side, the other, or combine both)
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4. Remove the conflict markers
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5. Stage the resolved file with `git add`
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6. Complete the merge with `git commit`
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## Useful Commands
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```bash
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# Merge a branch (may result in conflicts)
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git merge <branch-name>
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# Check the status during a conflict
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git status
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# See which files have conflicts
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git diff --name-only --diff-filter=U
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# View the conflict in detail
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git diff
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# After resolving, stage the file
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git add <file>
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# Complete the merge
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git commit
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# If you want to abort the merge
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git merge --abort
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# Visualize the branch history
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git log --oneline --graph --all
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```
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## Verification
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Run the verification script to check your solution:
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```bash
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.\verify.ps1
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```
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The verification will check that:
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- The merge conflict was resolved
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- The merge was completed successfully
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- Both configuration settings were preserved correctly
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- The commit history shows the merge
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## Tips
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- Don't panic when you see a conflict - it's a normal part of working with Git
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- Read the conflict markers carefully to understand both versions
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- You can use `git status` to see which files have conflicts
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- Always test your code after resolving conflicts to ensure it still works
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- The conflict markers (`<<<<<<<`, `=======`, `>>>>>>>`) must be completely removed from the final file
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## What You'll Learn
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Merge conflicts are inevitable when working on a team or even when working alone across multiple branches. Learning to resolve them confidently is an essential Git skill. This module teaches you the fundamentals of conflict resolution that you'll use throughout your development career.
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