diff --git a/01_essentials/05-reset-vs-revert/README.md b/01_essentials/05-reset-vs-revert/README.md deleted file mode 100644 index 2091945..0000000 --- a/01_essentials/05-reset-vs-revert/README.md +++ /dev/null @@ -1,198 +0,0 @@ -# Module 10: Reset vs Revert - -## Learning Objectives - -By the end of this module, you will: -- Understand the difference between `git reset` and `git revert` -- Know when to use reset vs revert -- Understand the three modes of reset (--soft, --mixed, --hard) -- Safely undo commits in both local and shared branches -- Understand the risks of rewriting history - -## Challenge Description - -You have two branches with problematic commits: -1. **local-feature**: A private branch with bad commits that you haven't shared with anyone -2. **shared-feature**: A branch that has been pushed and others might be using - -Your task is to: -1. Use `git reset` to remove the bad commit from the local-feature branch (safe because it's not shared) -2. Use `git revert` to undo the bad commit from the shared-feature branch (safe because it preserves history) - -## Key Concepts - -### Git Reset: Rewriting History - -`git reset` moves the branch pointer backward, effectively erasing commits from history. It has three modes: - -**--soft**: Moves HEAD, keeps changes staged -```bash -git reset --soft HEAD~1 -# Commit is gone, but changes are staged and ready to commit again -``` - -**--mixed** (default): Moves HEAD, keeps changes unstaged -```bash -git reset HEAD~1 -# Commit is gone, changes are in working directory but not staged -``` - -**--hard**: Moves HEAD, discards all changes -```bash -git reset --hard HEAD~1 -# Commit is gone, changes are PERMANENTLY DELETED -``` - -### Git Revert: Safe Undo - -`git revert` creates a NEW commit that undoes the changes from a previous commit. History is preserved. - -```bash -git revert -# Creates a new commit that reverses the specified commit -``` - -### Visual Comparison - -**Before (both branches):** -``` -A---B---C---D (D is the bad commit) -``` - -**After Reset (rewrites history):** -``` -A---B---C -``` -Commit D is gone. If anyone else had D, they'll have problems. - -**After Revert (preserves history):** -``` -A---B---C---D---E -``` -E is a new commit that undoes D. Everyone can pull E safely. - -### When to Use Each - -**Use Reset when:** -- The commits haven't been pushed to a shared repository -- You're cleaning up local commits before pushing -- You made a mistake locally and want to start over -- You're working alone on a branch - -**Use Revert when:** -- The commits have been pushed to a shared repository -- Others might have based work on these commits -- You want to preserve the complete history -- You need a safe, reversible undo operation - -### The Golden Rule - -**Never use `git reset` on commits that have been pushed to a shared branch!** - -This will cause problems for anyone who has pulled those commits. Use `git revert` instead. - -## Useful Commands - -```bash -# Reset (for local-only commits) -git reset --soft HEAD~1 # Undo commit, keep changes staged -git reset HEAD~1 # Undo commit, keep changes unstaged -git reset --hard HEAD~1 # Undo commit, discard changes (DANGEROUS!) - -# Reset to a specific commit -git reset --hard - -# Revert (for shared commits) -git revert -git revert HEAD # Revert the last commit - -# See what would be affected before resetting -git log --oneline -git diff HEAD~1 - -# If you reset by mistake, you can sometimes recover with reflog -git reflog -git reset --hard -``` - -## Verification - -Run the verification script to check your solution: - -```bash -.\verify.ps1 -``` - -The verification will check that: -- local-feature branch has the bad commit removed via reset -- shared-feature branch has the bad commit undone via revert -- shared-feature has a revert commit in the history -- All good commits are preserved - -## Challenge Steps - -1. Navigate to the challenge directory -2. You're on the local-feature branch with a bad commit -3. View commits: `git log --oneline` -4. Use `git reset --hard HEAD~1` to remove the bad commit -5. Switch to shared-feature: `git switch shared-feature` -6. View commits: `git log --oneline` -7. Find the hash of the "Add broken feature" commit -8. Use `git revert ` to undo it safely -9. Run the verification script - -## Tips - -- `HEAD~1` means "one commit before HEAD" -- `HEAD~2` means "two commits before HEAD" -- Always check `git log` before and after reset/revert -- `git reset --hard` is DANGEROUS - it permanently deletes uncommitted changes -- If you're unsure, use `git reset --soft` instead of `--hard` -- Revert will open an editor for the commit message - you can accept the default -- You can always use `.\reset.ps1` to start over if you make a mistake - -## Common Mistakes to Avoid - -### Mistake 1: Using Reset on Pushed Commits -```bash -# DON'T DO THIS if the commit was pushed! -git reset --hard HEAD~1 -git push --force # This will cause problems for others -``` - -### Mistake 2: Using --hard Without Checking -```bash -# This DELETES your work permanently! -git reset --hard HEAD~1 # Uncommitted changes are GONE -``` - -### Mistake 3: Reverting the Wrong Commit -```bash -# Always double-check the commit hash -git log --oneline -git show # Verify it's the right commit -git revert # Now revert it -``` - -## Recovery from Mistakes - -If you reset by accident, Git keeps a reflog: - -```bash -# See recent HEAD movements -git reflog - -# Find the commit you want to restore -# Output looks like: -# abc1234 HEAD@{0}: reset: moving to HEAD~1 -# def5678 HEAD@{1}: commit: The commit you just lost - -# Restore it -git reset --hard def5678 -``` - -The reflog is your safety net, but it only keeps history for about 30 days. - -## What You'll Learn - -Understanding when to use reset versus revert is crucial for safe Git usage. Reset is powerful but dangerous when used on shared commits, while revert is always safe but creates additional history. Mastering both commands and knowing which to use in different situations is a hallmark of Git expertise. The rule is simple: if in doubt, use revert - it's always safe. diff --git a/01_essentials/05-reset-vs-revert/reset.ps1 b/01_essentials/05-reset-vs-revert/reset.ps1 deleted file mode 100644 index 3adb925..0000000 --- a/01_essentials/05-reset-vs-revert/reset.ps1 +++ /dev/null @@ -1,22 +0,0 @@ -#!/usr/bin/env pwsh - -<# -.SYNOPSIS - Resets the reset vs revert challenge environment. - -.DESCRIPTION - Removes the existing challenge directory and runs setup.ps1 - to create a fresh challenge environment. -#> - -Write-Host "Resetting challenge environment..." -ForegroundColor Yellow - -# Remove existing challenge directory if present -if (Test-Path "challenge") { - Remove-Item -Path "challenge" -Recurse -Force - Write-Host "Removed existing challenge directory." -ForegroundColor Cyan -} - -# Run setup script -Write-Host "Running setup script...`n" -ForegroundColor Cyan -& ".\setup.ps1" diff --git a/01_essentials/05-reset-vs-revert/setup.ps1 b/01_essentials/05-reset-vs-revert/setup.ps1 deleted file mode 100644 index 4d787d1..0000000 --- a/01_essentials/05-reset-vs-revert/setup.ps1 +++ /dev/null @@ -1,190 +0,0 @@ -#!/usr/bin/env pwsh - -<# -.SYNOPSIS - Sets up the reset vs revert challenge environment. - -.DESCRIPTION - Creates a Git repository with two branches: - - local-feature: A private branch where reset should be used - - shared-feature: A pushed branch where revert should be used -#> - -# Remove existing challenge directory if present -if (Test-Path "challenge") { - Write-Host "Removing existing challenge directory..." -ForegroundColor Yellow - Remove-Item -Path "challenge" -Recurse -Force -} - -# Create challenge directory -Write-Host "Creating challenge environment..." -ForegroundColor Cyan -New-Item -ItemType Directory -Path "challenge" | Out-Null -Set-Location "challenge" - -# Initialize git repository -git init | Out-Null -git config user.name "Workshop User" | Out-Null -git config user.email "user@workshop.local" | Out-Null - -# Create initial commits on main -$app = @" -class Calculator: - def add(self, a, b): - return a + b - - def subtract(self, a, b): - return a - b -"@ - -Set-Content -Path "calculator.py" -Value $app -git add calculator.py -git commit -m "Initial calculator implementation" | Out-Null - -$readme = @" -# Calculator App - -A simple calculator application. -"@ - -Set-Content -Path "README.md" -Value $readme -git add README.md -git commit -m "Add README" | Out-Null - -# Create local-feature branch (private, not shared) -git checkout -b local-feature | Out-Null - -$appWithMultiply = @" -class Calculator: - def add(self, a, b): - return a + b - - def subtract(self, a, b): - return a - b - - def multiply(self, a, b): - return a * b -"@ - -Set-Content -Path "calculator.py" -Value $appWithMultiply -git add calculator.py -git commit -m "Add multiply function" | Out-Null - -# Add a bad commit that should be removed with reset -$appWithBadCode = @" -class Calculator: - def add(self, a, b): - return a + b - - def subtract(self, a, b): - return a - b - - def multiply(self, a, b): - return a * b - - # BUG: This is broken and should never have been committed! - def divide(self, a, b): - # Forgot to check for division by zero - return a / b # This will raise ZeroDivisionError for zero! -"@ - -Set-Content -Path "calculator.py" -Value $appWithBadCode -git add calculator.py -git commit -m "Add broken divide function - DO NOT KEEP" | Out-Null - -# Switch back to main for shared-feature branch -git checkout main | Out-Null - -# Create shared-feature branch (simulating a pushed/shared branch) -git checkout -b shared-feature | Out-Null - -$appWithPower = @" -class Calculator: - def add(self, a, b): - return a + b - - def subtract(self, a, b): - return a - b - - def power(self, a, b): - return a ** b -"@ - -Set-Content -Path "calculator.py" -Value $appWithPower -git add calculator.py -git commit -m "Add power function" | Out-Null - -# Add a bad commit that should be reverted (not reset) -$appWithBrokenFeature = @" -import math - -class Calculator: - def add(self, a, b): - return a + b - - def subtract(self, a, b): - return a - b - - def power(self, a, b): - return a ** b - - # BUG: This breaks the calculator! - def square_root(self, a): - # This implementation is wrong for negative numbers - return math.sqrt(a) # Raises ValueError for negative numbers without warning! -"@ - -Set-Content -Path "calculator.py" -Value $appWithBrokenFeature -git add calculator.py -git commit -m "Add broken feature" | Out-Null - -# Add another good commit after the bad one (to show that revert preserves subsequent commits) -$appWithMoreFeatures = @" -import math - -class Calculator: - def add(self, a, b): - return a + b - - def subtract(self, a, b): - return a - b - - def power(self, a, b): - return a ** b - - # BUG: This breaks the calculator! - def square_root(self, a): - # This implementation is wrong for negative numbers - return math.sqrt(a) # Raises ValueError for negative numbers without warning! - - def modulo(self, a, b): - return a % b -"@ - -Set-Content -Path "calculator.py" -Value $appWithMoreFeatures -git add calculator.py -git commit -m "Add modulo function" | Out-Null - -# Switch to local-feature for the challenge start -git checkout local-feature | Out-Null - -# Return to module directory -Set-Location .. - -Write-Host "`n========================================" -ForegroundColor Green -Write-Host "Challenge environment created!" -ForegroundColor Green -Write-Host "========================================" -ForegroundColor Green -Write-Host "`nYou have two branches with bad commits:" -ForegroundColor Cyan -Write-Host "`n1. local-feature (PRIVATE - not shared):" -ForegroundColor Yellow -Write-Host " - Has a broken divide function commit" -ForegroundColor White -Write-Host " - Safe to use 'git reset' to remove it" -ForegroundColor Green -Write-Host "`n2. shared-feature (PUBLIC - shared with team):" -ForegroundColor Yellow -Write-Host " - Has a broken feature commit" -ForegroundColor White -Write-Host " - Must use 'git revert' to undo it safely" -ForegroundColor Green -Write-Host "`nYour task:" -ForegroundColor Yellow -Write-Host "1. Navigate to the challenge directory: cd challenge" -ForegroundColor White -Write-Host "2. You're on local-feature - view commits: git log --oneline" -ForegroundColor White -Write-Host "3. Remove the bad commit with: git reset --hard HEAD~1" -ForegroundColor White -Write-Host "4. Switch to shared-feature: git checkout shared-feature" -ForegroundColor White -Write-Host "5. Find the 'Add broken feature' commit hash: git log --oneline" -ForegroundColor White -Write-Host "6. Revert it with: git revert " -ForegroundColor White -Write-Host "`nRun '../verify.ps1' from the challenge directory to check your solution.`n" -ForegroundColor Cyan diff --git a/01_essentials/05-reset-vs-revert/verify.ps1 b/01_essentials/05-reset-vs-revert/verify.ps1 deleted file mode 100644 index 7cf1bac..0000000 --- a/01_essentials/05-reset-vs-revert/verify.ps1 +++ /dev/null @@ -1,172 +0,0 @@ -#!/usr/bin/env pwsh - -<# -.SYNOPSIS - Verifies the reset vs revert challenge solution. - -.DESCRIPTION - Checks that the user correctly used reset on the local branch - and revert on the shared branch. -#> - -Set-Location "challenge" -ErrorAction SilentlyContinue - -# Check if challenge directory exists -if (-not (Test-Path "../verify.ps1")) { - Write-Host "Error: Please run this script from the module directory" -ForegroundColor Red - exit 1 -} - -if (-not (Test-Path ".")) { - Write-Host "Error: Challenge directory not found. Run setup.ps1 first." -ForegroundColor Red - Set-Location .. - exit 1 -} - -Write-Host "Verifying your solution..." -ForegroundColor Cyan - -# Check if git repository exists -if (-not (Test-Path ".git")) { - Write-Host "[FAIL] No git repository found." -ForegroundColor Red - Set-Location .. - exit 1 -} - -# Verify local-feature branch -Write-Host "`nChecking local-feature branch..." -ForegroundColor Cyan -git checkout local-feature 2>$null | Out-Null - -# Check commit count on local-feature (should be 3: initial + README + multiply) -$localCommitCount = (git rev-list --count local-feature 2>$null) -if ($localCommitCount -ne 3) { - Write-Host "[FAIL] local-feature should have 3 commits, found $localCommitCount" -ForegroundColor Red - if ($localCommitCount -gt 3) { - Write-Host "Hint: The bad commit should be removed. Use 'git reset --hard HEAD~1'" -ForegroundColor Yellow - } else { - Write-Host "Hint: You may have reset too far. Run ../reset.ps1 to start over." -ForegroundColor Yellow - } - Set-Location .. - exit 1 -} - -# Check that calculator.py exists -if (-not (Test-Path "calculator.py")) { - Write-Host "[FAIL] calculator.py not found." -ForegroundColor Red - Set-Location .. - exit 1 -} - -# Check calculator.py on local-feature -$localCalcContent = Get-Content "calculator.py" -Raw - -# Should have multiply function -if ($localCalcContent -notmatch "multiply") { - Write-Host "[FAIL] calculator.py should have the multiply function." -ForegroundColor Red - Set-Location .. - exit 1 -} - -# Should NOT have divide function (it was in the bad commit that should be reset) -if ($localCalcContent -match "divide") { - Write-Host "[FAIL] calculator.py should NOT have the divide function." -ForegroundColor Red - Write-Host "Hint: Use 'git reset --hard HEAD~1' to remove the bad commit" -ForegroundColor Yellow - Set-Location .. - exit 1 -} - -# Check commit messages on local-feature -$localCommits = git log --pretty=format:"%s" local-feature 2>$null -if ($localCommits -match "broken divide") { - Write-Host "[FAIL] The 'broken divide' commit should be removed from local-feature." -ForegroundColor Red - Write-Host "Hint: Use 'git reset --hard HEAD~1' to remove it" -ForegroundColor Yellow - Set-Location .. - exit 1 -} - -Write-Host "[PASS] local-feature branch correctly reset!" -ForegroundColor Green - -# Verify shared-feature branch -Write-Host "`nChecking shared-feature branch..." -ForegroundColor Cyan -git checkout shared-feature 2>$null | Out-Null - -# Check commit count on shared-feature -# Should be 6: initial + README + power + broken feature + modulo + revert -$sharedCommitCount = (git rev-list --count shared-feature 2>$null) -if ($sharedCommitCount -ne 6) { - Write-Host "[FAIL] shared-feature should have 6 commits, found $sharedCommitCount" -ForegroundColor Red - if ($sharedCommitCount -lt 6) { - Write-Host "Hint: You should REVERT the bad commit, not reset it." -ForegroundColor Yellow - Write-Host " Revert creates a new commit that undoes the bad one." -ForegroundColor Yellow - Write-Host " Use: git revert " -ForegroundColor Yellow - } else { - Write-Host "Hint: You should have exactly 6 commits after reverting." -ForegroundColor Yellow - } - Set-Location .. - exit 1 -} - -# Check that there's a revert commit -$sharedCommits = git log --pretty=format:"%s" shared-feature 2>$null -if ($sharedCommits -notmatch "Revert") { - Write-Host "[FAIL] No revert commit found on shared-feature." -ForegroundColor Red - Write-Host "Hint: Use 'git revert ' to undo the bad commit" -ForegroundColor Yellow - Write-Host " Find the hash with: git log --oneline" -ForegroundColor Yellow - Set-Location .. - exit 1 -} - -# Check calculator.py on shared-feature -$sharedCalcContent = Get-Content "calculator.py" -Raw - -# Should have power function -if ($sharedCalcContent -notmatch "power") { - Write-Host "[FAIL] calculator.py should have the power function." -ForegroundColor Red - Set-Location .. - exit 1 -} - -# Should have modulo function (commits after the reverted one should be preserved) -if ($sharedCalcContent -notmatch "modulo") { - Write-Host "[FAIL] calculator.py should have the modulo function." -ForegroundColor Red - Write-Host "Hint: Reverting should preserve commits made after the bad one" -ForegroundColor Yellow - Set-Location .. - exit 1 -} - -# Should NOT have square_root function (it was in the bad commit that should be reverted) -if ($sharedCalcContent -match "square_root") { - Write-Host "[FAIL] calculator.py should NOT have the square_root function." -ForegroundColor Red - Write-Host "Hint: The 'Add broken feature' commit should be reverted" -ForegroundColor Yellow - Write-Host " Use: git revert " -ForegroundColor Yellow - Set-Location .. - exit 1 -} - -# Verify the revert commit specifically reverted the "Add broken feature" commit -$revertCommitMessage = git log --grep="Revert" --pretty=format:"%s" -n 1 2>$null -if ($revertCommitMessage -notmatch "broken feature") { - Write-Host "[FAIL] The revert commit should mention 'broken feature'." -ForegroundColor Red - Write-Host "Hint: Make sure you reverted the correct commit (the one that added square_root)" -ForegroundColor Yellow - Set-Location .. - exit 1 -} - -Write-Host "[PASS] shared-feature branch correctly reverted!" -ForegroundColor Green - -# Success! -Write-Host "`n========================================" -ForegroundColor Green -Write-Host "SUCCESS! Challenge completed!" -ForegroundColor Green -Write-Host "========================================" -ForegroundColor Green -Write-Host "`nYou have successfully:" -ForegroundColor Cyan -Write-Host "- Used 'git reset' on local-feature (private branch)" -ForegroundColor White -Write-Host " Removed the bad commit completely from history" -ForegroundColor White -Write-Host "- Used 'git revert' on shared-feature (public branch)" -ForegroundColor White -Write-Host " Created a new commit that undoes the bad one" -ForegroundColor White -Write-Host " Preserved all history and subsequent commits" -ForegroundColor White -Write-Host "`nYou now understand when to use reset vs revert!" -ForegroundColor Green -Write-Host "`nKey takeaway:" -ForegroundColor Yellow -Write-Host "- Reset rewrites history (use only on private commits)" -ForegroundColor White -Write-Host "- Revert preserves history (safe for shared commits)`n" -ForegroundColor White - -Set-Location .. -exit 0 diff --git a/01_essentials/05-revert/README.md b/01_essentials/05-revert/README.md new file mode 100644 index 0000000..5d91d19 --- /dev/null +++ b/01_essentials/05-revert/README.md @@ -0,0 +1,638 @@ +# Module 05: Git Revert - Safe Undoing + +## About This Module + +Welcome to Module 05, where you'll learn the **safe, team-friendly way to undo changes** in Git. Unlike destructive commands that erase history, `git revert` creates new commits that undo previous changes while preserving the complete project history. + +**Why revert is important:** +- ✅ Safe for shared/pushed commits +- ✅ Preserves complete history and audit trail +- ✅ Transparent to your team +- ✅ Can be undone itself if needed +- ✅ Works with any commit in history + +**Key principle:** Revert doesn't erase mistakes—it documents how you fixed them. + +## Learning Objectives + +By completing this module, you will: + +1. Revert regular commits safely while preserving surrounding changes +2. Revert merge commits using the `-m` flag +3. Understand merge commit parent numbering +4. Handle the re-merge problem that occurs after reverting merges +5. Revert multiple commits at once +6. Know when to use revert vs. other undo strategies + +## Prerequisites + +Before starting this module, you should be comfortable with: +- Creating commits (`git commit`) +- Viewing commit history (`git log`) +- Understanding branches and merging (Module 03) + +## Setup + +Run the setup script to create the challenge environment: + +```powershell +./setup.ps1 +``` + +This creates a `challenge/` directory with three branches demonstrating different revert scenarios: +- `regular-revert` - Basic commit reversion +- `merge-revert` - Merge commit reversion +- `multi-revert` - Multiple commit reversion + +## Challenge 1: Reverting a Regular Commit + +### Scenario + +You're working on a calculator application. A developer added a `divide` function that crashes when dividing by zero. The bug was discovered after subsequent commits were made, so you can't just delete it—you need to revert it while keeping the commits that came after. + +### Your Task + +1. Navigate to the challenge directory: + ```bash + cd challenge + ``` + +2. You should be on the `regular-revert` branch. View the commit history: + ```bash + git log --oneline + ``` + +3. Find the commit with the broken divide function (message: "Add broken divide function - needs to be reverted!") + +4. Revert that specific commit: + ```bash + git revert + ``` + +5. Git will open your editor for the revert commit message. The default message is fine—save and close. + +### What to Observe + +After reverting, check: + +```bash +# View the new revert commit +git log --oneline + +# Check that divide function is gone +cat calculator.py | grep "def divide" # Should return nothing + +# Check that modulo function still exists (it came after the bad commit) +cat calculator.py | grep "def modulo" # Should find it + +# Check that multiply function still exists (it came before the bad commit) +cat calculator.py | grep "def multiply" # Should find it +``` + +**Key insight:** Revert creates a new commit that undoes the changes from the target commit, but leaves all other commits intact. + +### Understanding the Timeline + +``` +Before revert: +main.py (initial) → multiply (good) → divide (BAD) → modulo (good) + ↑ + We want to undo THIS + +After revert: +main.py (initial) → multiply (good) → divide (BAD) → modulo (good) → revert divide (new commit) + ↑ + Removes divide, keeps modulo +``` + +The revert commit adds a new point in history that undoes the divide changes. + +## Challenge 2: Reverting a Merge Commit + +### Scenario + +Your team merged a `feature-auth` branch that added authentication functionality. After deployment, you discovered the authentication system has critical security issues. You need to revert the entire merge while the security team redesigns the feature. + +**This is different from reverting a regular commit!** Merge commits have **two parents**, so you must tell Git which parent to keep. + +### Understanding Merge Commit Parents + +When you merge a feature branch into main: + +``` + feature-auth (parent 2) + ↓ + C---D + / \ +A---B-----M ← Merge commit (has TWO parents) + ↑ +parent 1 (main) +``` + +The merge commit `M` has: +- **Parent 1**: The branch you merged INTO (main) +- **Parent 2**: The branch you merged FROM (feature-auth) + +When reverting a merge, you must specify which parent to keep using the `-m` flag: +- `-m 1` means "keep parent 1" (main) - **Most common** +- `-m 2` means "keep parent 2" (feature-auth) - Rare + +**In practice:** You almost always use `-m 1` to keep the main branch and undo the feature branch changes. + +### Your Task + +1. Switch to the merge-revert branch: + ```bash + git switch merge-revert + ``` + +2. View the commit history and find the merge commit: + ```bash + git log --oneline --graph + ``` + + Look for: "Merge feature-auth branch" + +3. Revert the merge commit using `-m 1`: + ```bash + git revert -m 1 + ``` + + **Explanation:** + - `-m 1` tells Git to keep parent 1 (main branch) + - This undoes all changes from the feature-auth branch + - Creates a new "revert merge" commit + +4. Save the default commit message and check the result: + ```bash + # Verify auth.py is gone + ls auth.py # Should not exist + + # Verify calculator.py no longer imports auth + cat calculator.py | grep "from auth" # Should return nothing + ``` + +### What Happens Without -m? + +If you try to revert a merge commit without the `-m` flag: + +```bash +git revert +# Error: commit is a merge but no -m option was given +``` + +Git doesn't know which parent you want to keep, so it refuses to proceed. + +### The Re-Merge Problem + +**Important gotcha:** After reverting a merge, you **cannot simply re-merge** the same branch! + +Here's why: + +``` +Initial merge: +A---B---M (merged feature-auth) + ↑ + All changes from feature-auth are now in main + +After revert: +A---B---M---R (reverted merge) + ↑ + Changes removed, but Git remembers they were merged + +Attempting to re-merge: +A---B---M---R---M2 (try to merge feature-auth again) + ↑ + Git thinks: "I already merged these commits, + nothing new to add!" (Empty merge) +``` + +**Solutions if you need to re-merge:** + +1. **Revert the revert** (recommended): + ```bash + git revert + ``` + This brings back all the feature-auth changes. + +2. **Cherry-pick new commits** from the feature branch: + ```bash + git cherry-pick + ``` + +3. **Merge with --no-ff** and resolve conflicts manually (advanced). + +### When to Revert Merges + +Revert merge commits when: +- ✅ Feature causes production issues +- ✅ Need to temporarily remove a feature +- ✅ Discovered critical bugs after merging +- ✅ Security issues require immediate rollback + +Don't revert merges when: +- ❌ You just need to fix a small bug (fix it with a new commit instead) +- ❌ You plan to re-merge the same branch soon (use reset if local, or revert-the-revert later) + +## Challenge 3: Reverting Multiple Commits + +### Scenario + +Two separate commits added broken mathematical functions (`square_root` and `logarithm`). Both have critical bugs and need to be removed. You can revert multiple commits at once. + +### Your Task + +1. Switch to the multi-revert branch: + ```bash + git switch multi-revert + ``` + +2. View the commit history: + ```bash + git log --oneline + ``` + + Find the two commits: + - "Add broken square_root - REVERT THIS!" + - "Add broken logarithm - REVERT THIS TOO!" + +3. Revert both commits in one command: + ```bash + git revert + ``` + + **Important:** List commits from **oldest to newest** for cleanest history. + + Alternatively, revert them one at a time: + ```bash + git revert + git revert + ``` + +4. Git will prompt for a commit message for each revert. Accept the defaults. + +5. Verify the result: + ```bash + # Check that both bad functions are gone + cat calculator.py | grep "def square_root" # Should return nothing + cat calculator.py | grep "def logarithm" # Should return nothing + + # Check that good functions remain + cat calculator.py | grep "def power" # Should find it + cat calculator.py | grep "def absolute" # Should find it + ``` + +### Multi-Revert Strategies + +**Reverting a range of commits:** + +```bash +# Revert commits from A to B (inclusive) +git revert A^..B + +# Example: Revert last 3 commits +git revert HEAD~3..HEAD +``` + +**Reverting without auto-commit:** + +```bash +# Stage revert changes without committing +git revert --no-commit + +# Review changes +git diff --staged + +# Commit when ready +git commit +``` + +This is useful when reverting multiple commits and you want one combined revert commit. + +## Verification + +Verify your solutions by running the verification script: + +```bash +cd .. # Return to module directory +./verify.ps1 +``` + +The script checks that: +- ✅ Revert commits were created (not destructive deletion) +- ✅ Bad code is removed +- ✅ Good code before and after is preserved +- ✅ Merge commits still exist in history +- ✅ Proper use of `-m` flag for merge reverts + +## Command Reference + +### Basic Revert + +```bash +# Revert a specific commit +git revert + +# Revert the most recent commit +git revert HEAD + +# Revert the second-to-last commit +git revert HEAD~1 +``` + +### Merge Commit Revert + +```bash +# Revert a merge commit (keep parent 1) +git revert -m 1 + +# Revert a merge commit (keep parent 2) - rare +git revert -m 2 +``` + +### Multiple Commits + +```bash +# Revert multiple specific commits +git revert + +# Revert a range of commits (oldest^..newest) +git revert ^.. + +# Revert last 3 commits +git revert HEAD~3..HEAD +``` + +### Revert Options + +```bash +# Revert but don't commit automatically +git revert --no-commit + +# Revert and edit the commit message +git revert --edit + +# Revert without opening editor (use default message) +git revert --no-edit + +# Abort a revert in progress (if conflicts) +git revert --abort + +# Continue revert after resolving conflicts +git revert --continue +``` + +## When to Use Git Revert + +Use `git revert` when: + +- ✅ **Commits are already pushed** - Safe for shared history +- ✅ **Working in a team** - Transparent to everyone +- ✅ **Need audit trail** - Shows what was undone and why +- ✅ **Public repositories** - Can't rewrite public history +- ✅ **Undoing old commits** - Can revert commits from weeks ago +- ✅ **Production hotfixes** - Safe emergency rollback + +**Golden Rule:** If others might have your commits, use revert. + +## When NOT to Use Git Revert + +Consider alternatives when: + +- ❌ **Commits are still local** - Use `git reset` instead (Module 06) +- ❌ **Just want to edit a commit** - Use `git commit --amend` +- ❌ **Haven't pushed yet** - Reset is cleaner for local cleanup +- ❌ **Need to combine commits** - Use interactive rebase +- ❌ **Reverting creates complex conflicts** - Might need manual fix forward + +## Revert vs. Reset vs. Rebase + +| Command | History | Safety | Use Case | +|---------|---------|--------|----------| +| **revert** | Preserves | ✅ Safe | Undo pushed commits | +| **reset** | Erases | ⚠️ Dangerous | Clean up local commits | +| **rebase** | Rewrites | ⚠️ Dangerous | Polish commit history | + +**This module teaches revert.** You'll learn reset in Module 06. + +## Handling Revert Conflicts + +Sometimes reverting causes conflicts if subsequent changes touched the same code: + +```bash +# Start revert +git revert + +# If conflicts occur: +# Conflict in calculator.py +# CONFLICT (content): Merge conflict in calculator.py +``` + +**To resolve:** + +1. Open conflicted files and fix conflicts (look for `<<<<<<<` markers) +2. Stage resolved files: + ```bash + git add + ``` +3. Continue the revert: + ```bash + git revert --continue + ``` + +Or abort if you change your mind: +```bash +git revert --abort +``` + +## Common Mistakes + +### 1. Forgetting -m for Merge Commits + +```bash +# ❌ Wrong - will fail +git revert + +# ✅ Correct +git revert -m 1 +``` + +### 2. Trying to Re-Merge After Revert + +```bash +# After reverting a merge: +git revert -m 1 + +# ❌ This won't work as expected +git merge feature-branch # Empty merge! + +# ✅ Do this instead +git revert # Revert the revert +``` + +### 3. Using Reset on Pushed Commits + +```bash +# ❌ NEVER do this with pushed commits +git reset --hard HEAD~3 + +# ✅ Do this instead +git revert HEAD~3..HEAD +``` + +### 4. Reverting Commits in Wrong Order + +When reverting multiple related commits, revert from newest to oldest: + +```bash +# If you have: A → B → C (and C depends on B) + +# ✅ Correct order +git revert C +git revert B + +# ❌ Wrong order (may cause conflicts) +git revert B # Conflict! C still references B +git revert C +``` + +## Best Practices + +1. **Write clear revert messages:** + ```bash + git revert -m "Revert authentication - security issue #1234" + ``` + +2. **Link to issue tracking:** + ``` + Revert "Add new payment system" + + This reverts commit abc123. + + Critical bug in payment processing. + See bug tracker: ISSUE-1234 + ``` + +3. **Test after reverting:** + - Run your test suite + - Verify the application still works + - Check no unintended changes occurred + +4. **Communicate with team:** + - Announce reverts in team chat + - Explain why the revert was necessary + - Provide timeline for re-introducing the feature + +5. **Keep reverts focused:** + - Revert the minimum necessary + - Don't bundle multiple unrelated reverts + - One problem = one revert commit + +## Troubleshooting + +### "Commit is a merge but no -m option was given" + +**Problem:** Trying to revert a merge commit without `-m`. + +**Solution:** +```bash +git revert -m 1 +``` + +### "Empty Revert / No Changes" + +**Problem:** Revert doesn't seem to do anything. + +**Possible causes:** +- Commit was already reverted +- Subsequent commits already undid the changes +- Wrong commit hash + +**Solution:** +```bash +# Check what the commit actually changed +git show + +# Check if already reverted +git log --grep="Revert" +``` + +### "Conflicts During Revert" + +**Problem:** Revert causes merge conflicts. + +**Why:** Subsequent commits modified the same code. + +**Solution:** +1. Manually resolve conflicts in affected files +2. `git add ` +3. `git revert --continue` + +Or consider fixing forward with a new commit instead of reverting. + +### "Can't Re-Merge After Reverting Merge" + +**Problem:** After reverting a merge, re-merging the branch brings no changes. + +**Solution:** Revert the revert commit: +```bash +# Find the revert commit +git log --oneline + +# Revert the revert (brings changes back) +git revert +``` + +## Advanced: Revert Internals + +Understanding what revert does under the hood: + +```bash +# Revert creates a new commit with inverse changes +git revert + +# This is equivalent to: +git diff ^.. > changes.patch +patch -R < changes.patch # Apply in reverse +git add . +git commit -m "Revert ''" +``` + +**Key insight:** Revert computes the diff of the target commit, inverts it, and applies it as a new commit. + +## Going Further + +Now that you understand revert, you're ready for: + +- **Module 06: Git Reset** - Learn the dangerous but powerful local history rewriting +- **Module 07: Git Stash** - Temporarily set aside uncommitted changes +- **Module 08: Multiplayer Git** - Collaborate with advanced workflows + +## Summary + +You've learned: + +- ✅ `git revert` creates new commits that undo previous changes +- ✅ Revert is safe for shared/pushed commits +- ✅ Merge commits require `-m 1` or `-m 2` flag +- ✅ Parent 1 = branch merged into, Parent 2 = branch merged from +- ✅ Can't simply re-merge after reverting a merge +- ✅ Multiple commits can be reverted in one command +- ✅ Revert preserves complete history for audit trails + +**The Golden Rule of Revert:** Use revert for any commit that might be shared with others. + +## Next Steps + +1. Complete all three challenge scenarios +2. Run `./verify.ps1` to check your solutions +3. Experiment with reverting different commits +4. Move on to Module 06: Git Reset (dangerous but powerful!) + +--- + +**Need Help?** +- Review the command reference above +- Check the troubleshooting section +- Re-run `./setup.ps1` to start fresh +- Practice reverting in different orders to understand the behavior diff --git a/01_essentials/05-revert/reset.ps1 b/01_essentials/05-revert/reset.ps1 new file mode 100644 index 0000000..d40ab84 --- /dev/null +++ b/01_essentials/05-revert/reset.ps1 @@ -0,0 +1,24 @@ +#!/usr/bin/env pwsh +<# +.SYNOPSIS + Resets the Module 05 challenge environment to start fresh. + +.DESCRIPTION + This script removes the challenge directory and re-runs setup.ps1 + to create a fresh challenge environment. +#> + +Write-Host "`n=== Resetting Module 05: Git Revert Challenge ===" -ForegroundColor Cyan + +# Check if challenge directory exists +if (Test-Path "challenge") { + Write-Host "Removing existing challenge directory..." -ForegroundColor Yellow + Remove-Item -Recurse -Force "challenge" + Write-Host "[OK] Challenge directory removed" -ForegroundColor Green +} else { + Write-Host "[INFO] No existing challenge directory found" -ForegroundColor Yellow +} + +# Run setup to create fresh environment +Write-Host "`nRunning setup to create fresh challenge environment..." -ForegroundColor Cyan +& "$PSScriptRoot/setup.ps1" diff --git a/01_essentials/05-revert/setup.ps1 b/01_essentials/05-revert/setup.ps1 new file mode 100644 index 0000000..f3e3911 --- /dev/null +++ b/01_essentials/05-revert/setup.ps1 @@ -0,0 +1,373 @@ +#!/usr/bin/env pwsh +<# +.SYNOPSIS + Sets up the Module 05 challenge environment for learning git revert. + +.DESCRIPTION + This script creates a challenge directory with three branches demonstrating + different revert scenarios: + - regular-revert: Basic revert of a single bad commit + - merge-revert: Reverting a merge commit with -m flag + - multi-revert: Reverting multiple commits at once +#> + +Write-Host "`n=== Setting up Module 05: Git Revert Challenge ===" -ForegroundColor Cyan + +# Remove existing challenge directory if it exists +if (Test-Path "challenge") { + Write-Host "Removing existing challenge directory..." -ForegroundColor Yellow + Remove-Item -Recurse -Force "challenge" +} + +# Create fresh challenge directory +Write-Host "Creating challenge directory..." -ForegroundColor Green +New-Item -ItemType Directory -Path "challenge" | Out-Null +Set-Location "challenge" + +# Initialize Git repository +Write-Host "Initializing Git repository..." -ForegroundColor Green +git init | Out-Null + +# Configure git for this repository +git config user.name "Workshop Student" +git config user.email "student@example.com" + +# ============================================================================ +# SCENARIO 1: Regular Revert (Basic) +# ============================================================================ +Write-Host "`nScenario 1: Creating regular-revert branch..." -ForegroundColor Cyan + +# Initial commit +$calcContent = @" +# calculator.py - Simple calculator + +def add(a, b): + """Add two numbers.""" + return a + b + +def subtract(a, b): + """Subtract b from a.""" + return a - b +"@ +Set-Content -Path "calculator.py" -Value $calcContent +git add . +git commit -m "Initial calculator implementation" | Out-Null + +# Create regular-revert branch +git switch -c regular-revert | Out-Null + +# Good commit: Add multiply +$calcContent = @" +# calculator.py - Simple calculator + +def add(a, b): + """Add two numbers.""" + return a + b + +def subtract(a, b): + """Subtract b from a.""" + return a - b + +def multiply(a, b): + """Multiply two numbers.""" + return a * b +"@ +Set-Content -Path "calculator.py" -Value $calcContent +git add . +git commit -m "Add multiply function" | Out-Null + +# BAD commit: Add broken divide function +$calcContent = @" +# calculator.py - Simple calculator + +def add(a, b): + """Add two numbers.""" + return a + b + +def subtract(a, b): + """Subtract b from a.""" + return a - b + +def multiply(a, b): + """Multiply two numbers.""" + return a * b + +def divide(a, b): + """Divide a by b - BROKEN: doesn't handle division by zero!""" + return a / b # This will crash if b is 0! +"@ +Set-Content -Path "calculator.py" -Value $calcContent +git add . +git commit -m "Add broken divide function - needs to be reverted!" | Out-Null + +# Good commit: Add modulo (after bad commit) +$calcContent = @" +# calculator.py - Simple calculator + +def add(a, b): + """Add two numbers.""" + return a + b + +def subtract(a, b): + """Subtract b from a.""" + return a - b + +def multiply(a, b): + """Multiply two numbers.""" + return a * b + +def divide(a, b): + """Divide a by b - BROKEN: doesn't handle division by zero!""" + return a / b # This will crash if b is 0! + +def modulo(a, b): + """Return remainder of a divided by b.""" + return a % b +"@ +Set-Content -Path "calculator.py" -Value $calcContent +git add . +git commit -m "Add modulo function" | Out-Null + +Write-Host "[CREATED] regular-revert branch with bad divide commit" -ForegroundColor Green + +# ============================================================================ +# SCENARIO 2: Merge Revert (Merge Commit with -m flag) +# ============================================================================ +Write-Host "`nScenario 2: Creating merge-revert scenario..." -ForegroundColor Cyan + +# Switch back to main +git switch main | Out-Null + +# Create merge-revert branch +git switch -c merge-revert | Out-Null + +# Create a feature branch to merge +git switch -c feature-auth | Out-Null + +# Add auth functionality +$authContent = @" +# auth.py - Authentication module + +def login(username, password): + \"\"\"Login user.\"\"\" + print(f"Logging in {username}...") + return True + +def logout(username): + \"\"\"Logout user.\"\"\" + print(f"Logging out {username}...") + return True +"@ +Set-Content -Path "auth.py" -Value $authContent +git add . +git commit -m "Add authentication module" | Out-Null + +# Add password validation +$authContent = @" +# auth.py - Authentication module + +def validate_password(password): + \"\"\"Validate password strength.\"\"\" + return len(password) >= 8 + +def login(username, password): + \"\"\"Login user.\"\"\" + if not validate_password(password): + print("Password too weak!") + return False + print(f"Logging in {username}...") + return True + +def logout(username): + \"\"\"Logout user.\"\"\" + print(f"Logging out {username}...") + return True +"@ +Set-Content -Path "auth.py" -Value $authContent +git add . +git commit -m "Add password validation" | Out-Null + +# Integrate auth into calculator (part of the feature branch) +$calcContent = @" +# calculator.py - Simple calculator +from auth import login + +def add(a, b): + """Add two numbers.""" + return a + b + +def subtract(a, b): + """Subtract b from a.""" + return a - b + +def secure_divide(a, b, username): + """Secure divide - requires authentication.""" + if login(username, "password123"): + return a / b + return None +"@ +Set-Content -Path "calculator.py" -Value $calcContent +git add . +git commit -m "Integrate auth into calculator" | Out-Null + +# Switch back to merge-revert and merge feature-auth +git switch merge-revert | Out-Null +git merge feature-auth --no-ff -m "Merge feature-auth branch" | Out-Null + +Write-Host "[CREATED] merge-revert branch with merge commit to revert" -ForegroundColor Green + +# ============================================================================ +# SCENARIO 3: Multi Revert (Multiple Bad Commits) +# ============================================================================ +Write-Host "`nScenario 3: Creating multi-revert branch..." -ForegroundColor Cyan + +# Switch back to main +git switch main | Out-Null + +# Create multi-revert branch +git switch -c multi-revert | Out-Null + +# Reset calculator to simple version +$calcContent = @" +# calculator.py - Simple calculator + +def add(a, b): + """Add two numbers.""" + return a + b + +def subtract(a, b): + """Subtract b from a.""" + return a - b +"@ +Set-Content -Path "calculator.py" -Value $calcContent +git add . +git commit -m "Reset to basic calculator" | Out-Null + +# Good commit: Add power function +$calcContent = @" +# calculator.py - Simple calculator + +def add(a, b): + """Add two numbers.""" + return a + b + +def subtract(a, b): + """Subtract b from a.""" + return a - b + +def power(a, b): + """Raise a to the power of b.""" + return a ** b +"@ +Set-Content -Path "calculator.py" -Value $calcContent +git add . +git commit -m "Add power function" | Out-Null + +# BAD commit 1: Add broken square_root +$calcContent = @" +# calculator.py - Simple calculator + +def add(a, b): + """Add two numbers.""" + return a + b + +def subtract(a, b): + """Subtract b from a.""" + return a - b + +def power(a, b): + """Raise a to the power of b.""" + return a ** b + +def square_root(a): + """BROKEN: Returns wrong result for negative numbers!""" + return a ** 0.5 # This returns NaN for negative numbers! +"@ +Set-Content -Path "calculator.py" -Value $calcContent +git add . +git commit -m "Add broken square_root - REVERT THIS!" | Out-Null + +# BAD commit 2: Add broken logarithm +$calcContent = @" +# calculator.py - Simple calculator + +def add(a, b): + """Add two numbers.""" + return a + b + +def subtract(a, b): + """Subtract b from a.""" + return a - b + +def power(a, b): + """Raise a to the power of b.""" + return a ** b + +def square_root(a): + """BROKEN: Returns wrong result for negative numbers!""" + return a ** 0.5 # This returns NaN for negative numbers! + +def logarithm(a): + """BROKEN: Doesn't handle zero or negative numbers!""" + import math + return math.log(a) # This crashes for a <= 0! +"@ +Set-Content -Path "calculator.py" -Value $calcContent +git add . +git commit -m "Add broken logarithm - REVERT THIS TOO!" | Out-Null + +# Good commit: Add absolute value (after bad commits) +$calcContent = @" +# calculator.py - Simple calculator + +def add(a, b): + """Add two numbers.""" + return a + b + +def subtract(a, b): + """Subtract b from a.""" + return a - b + +def power(a, b): + """Raise a to the power of b.""" + return a ** b + +def square_root(a): + """BROKEN: Returns wrong result for negative numbers!""" + return a ** 0.5 # This returns NaN for negative numbers! + +def logarithm(a): + """BROKEN: Doesn't handle zero or negative numbers!""" + import math + return math.log(a) # This crashes for a <= 0! + +def absolute(a): + """Return absolute value of a.""" + return abs(a) +"@ +Set-Content -Path "calculator.py" -Value $calcContent +git add . +git commit -m "Add absolute value function" | Out-Null + +Write-Host "[CREATED] multi-revert branch with two bad commits to revert" -ForegroundColor Green + +# ============================================================================ +# Return to regular-revert to start +# ============================================================================ +git switch regular-revert | Out-Null + +# Return to module directory +Set-Location .. + +Write-Host "`n=== Setup Complete! ===" -ForegroundColor Green +Write-Host "`nThree revert scenarios have been created:" -ForegroundColor Cyan +Write-Host " 1. regular-revert - Revert a single bad commit (basic)" -ForegroundColor White +Write-Host " 2. merge-revert - Revert a merge commit with -m flag" -ForegroundColor White +Write-Host " 3. multi-revert - Revert multiple bad commits" -ForegroundColor White +Write-Host "`nYou are currently on the 'regular-revert' branch." -ForegroundColor Cyan +Write-Host "`nNext steps:" -ForegroundColor Cyan +Write-Host " 1. cd challenge" -ForegroundColor White +Write-Host " 2. Read the README.md for detailed instructions" -ForegroundColor White +Write-Host " 3. Complete each revert challenge" -ForegroundColor White +Write-Host " 4. Run '..\verify.ps1' to check your solutions" -ForegroundColor White +Write-Host "" diff --git a/01_essentials/05-revert/verify.ps1 b/01_essentials/05-revert/verify.ps1 new file mode 100644 index 0000000..0f32470 --- /dev/null +++ b/01_essentials/05-revert/verify.ps1 @@ -0,0 +1,226 @@ +#!/usr/bin/env pwsh +<# +.SYNOPSIS + Verifies the Module 05 challenge solutions. + +.DESCRIPTION + Checks that all three revert scenarios have been completed correctly: + - regular-revert: Single commit reverted + - merge-revert: Merge commit reverted with -m flag + - multi-revert: Multiple commits reverted +#> + +Write-Host "`n=== Verifying Module 05: Git Revert Solutions ===" -ForegroundColor Cyan + +$allChecksPassed = $true +$originalDir = Get-Location + +# Check if challenge directory exists +if (-not (Test-Path "challenge")) { + Write-Host "[FAIL] Challenge directory not found. Run setup.ps1 first." -ForegroundColor Red + exit 1 +} + +Set-Location "challenge" + +# Check if git repository exists +if (-not (Test-Path ".git")) { + Write-Host "[FAIL] Not a git repository. Run setup.ps1 first." -ForegroundColor Red + Set-Location $originalDir + exit 1 +} + +# ============================================================================ +# SCENARIO 1: Regular Revert Verification +# ============================================================================ +Write-Host "`n=== Scenario 1: Regular Revert ===" -ForegroundColor Cyan + +git switch regular-revert 2>&1 | Out-Null + +if ($LASTEXITCODE -ne 0) { + Write-Host "[FAIL] regular-revert branch not found" -ForegroundColor Red + $allChecksPassed = $false +} else { + # Check that a revert commit exists + $revertCommit = git log --oneline --grep="Revert" 2>$null + if ($revertCommit) { + Write-Host "[PASS] Revert commit found" -ForegroundColor Green + } else { + Write-Host "[FAIL] No revert commit found" -ForegroundColor Red + Write-Host "[HINT] Use: git revert " -ForegroundColor Yellow + $allChecksPassed = $false + } + + # Check that calculator.py exists + if (Test-Path "calculator.py") { + $calcContent = Get-Content "calculator.py" -Raw + + # Check that divide function is NOT in the code (was reverted) + if ($calcContent -notmatch "def divide") { + Write-Host "[PASS] Broken divide function successfully reverted" -ForegroundColor Green + } else { + Write-Host "[FAIL] divide function still exists (should be reverted)" -ForegroundColor Red + Write-Host "[HINT] The bad commit should be reverted, removing the divide function" -ForegroundColor Yellow + $allChecksPassed = $false + } + + # Check that modulo function still exists (should be preserved) + if ($calcContent -match "def modulo") { + Write-Host "[PASS] modulo function preserved (good commit after bad one)" -ForegroundColor Green + } else { + Write-Host "[FAIL] modulo function missing (should still exist)" -ForegroundColor Red + Write-Host "[HINT] Only revert the bad commit, not the good ones after it" -ForegroundColor Yellow + $allChecksPassed = $false + } + + # Check that multiply function exists (should be preserved) + if ($calcContent -match "def multiply") { + Write-Host "[PASS] multiply function preserved (good commit before bad one)" -ForegroundColor Green + } else { + Write-Host "[FAIL] multiply function missing" -ForegroundColor Red + $allChecksPassed = $false + } + } else { + Write-Host "[FAIL] calculator.py not found" -ForegroundColor Red + $allChecksPassed = $false + } +} + +# ============================================================================ +# SCENARIO 2: Merge Revert Verification +# ============================================================================ +Write-Host "`n=== Scenario 2: Merge Revert ===" -ForegroundColor Cyan + +git switch merge-revert 2>&1 | Out-Null + +if ($LASTEXITCODE -ne 0) { + Write-Host "[FAIL] merge-revert branch not found" -ForegroundColor Red + $allChecksPassed = $false +} else { + # Check that a revert commit for the merge exists + $revertMerge = git log --oneline --grep="Revert.*Merge" 2>$null + if ($revertMerge) { + Write-Host "[PASS] Merge revert commit found" -ForegroundColor Green + } else { + Write-Host "[FAIL] No merge revert commit found" -ForegroundColor Red + Write-Host "[HINT] Use: git revert -m 1 " -ForegroundColor Yellow + $allChecksPassed = $false + } + + # Check that the original merge commit still exists (revert doesn't erase it) + $mergeCommit = git log --merges --oneline --grep="Merge feature-auth" 2>$null + if ($mergeCommit) { + Write-Host "[PASS] Original merge commit still in history (not erased)" -ForegroundColor Green + } else { + Write-Host "[INFO] Original merge commit not found (this is OK if you used a different approach)" -ForegroundColor Yellow + } + + # Check that auth.py no longer exists or its effects are reverted + if (-not (Test-Path "auth.py")) { + Write-Host "[PASS] auth.py removed (merge reverted successfully)" -ForegroundColor Green + } else { + Write-Host "[INFO] auth.py still exists (check if merge was fully reverted)" -ForegroundColor Yellow + } + + # Check that calculator.py exists + if (Test-Path "calculator.py") { + $calcContent = Get-Content "calculator.py" -Raw + + # After reverting the merge, calculator shouldn't import auth + if ($calcContent -notmatch "from auth import") { + Write-Host "[PASS] Auth integration reverted from calculator.py" -ForegroundColor Green + } else { + Write-Host "[FAIL] calculator.py still imports auth (merge not fully reverted)" -ForegroundColor Red + Write-Host "[HINT] Reverting the merge should remove the auth integration" -ForegroundColor Yellow + $allChecksPassed = $false + } + } +} + +# ============================================================================ +# SCENARIO 3: Multi Revert Verification +# ============================================================================ +Write-Host "`n=== Scenario 3: Multi Revert ===" -ForegroundColor Cyan + +git switch multi-revert 2>&1 | Out-Null + +if ($LASTEXITCODE -ne 0) { + Write-Host "[FAIL] multi-revert branch not found" -ForegroundColor Red + $allChecksPassed = $false +} else { + # Count revert commits + $revertCommits = git log --oneline --grep="Revert" 2>$null + $revertCount = ($revertCommits | Measure-Object).Count + + if ($revertCount -ge 2) { + Write-Host "[PASS] Found $revertCount revert commits (expected at least 2)" -ForegroundColor Green + } else { + Write-Host "[FAIL] Found only $revertCount revert commit(s), need at least 2" -ForegroundColor Red + Write-Host "[HINT] Revert both bad commits: git revert " -ForegroundColor Yellow + $allChecksPassed = $false + } + + # Check calculator.py content + if (Test-Path "calculator.py") { + $calcContent = Get-Content "calculator.py" -Raw + + # Check that square_root is NOT in code (reverted) + if ($calcContent -notmatch "def square_root") { + Write-Host "[PASS] Broken square_root function reverted" -ForegroundColor Green + } else { + Write-Host "[FAIL] square_root function still exists (should be reverted)" -ForegroundColor Red + $allChecksPassed = $false + } + + # Check that logarithm is NOT in code (reverted) + if ($calcContent -notmatch "def logarithm") { + Write-Host "[PASS] Broken logarithm function reverted" -ForegroundColor Green + } else { + Write-Host "[FAIL] logarithm function still exists (should be reverted)" -ForegroundColor Red + $allChecksPassed = $false + } + + # Check that power function still exists (good commit before bad ones) + if ($calcContent -match "def power") { + Write-Host "[PASS] power function preserved" -ForegroundColor Green + } else { + Write-Host "[FAIL] power function missing (should still exist)" -ForegroundColor Red + $allChecksPassed = $false + } + + # Check that absolute function still exists (good commit after bad ones) + if ($calcContent -match "def absolute") { + Write-Host "[PASS] absolute function preserved" -ForegroundColor Green + } else { + Write-Host "[FAIL] absolute function missing (should still exist)" -ForegroundColor Red + $allChecksPassed = $false + } + } else { + Write-Host "[FAIL] calculator.py not found" -ForegroundColor Red + $allChecksPassed = $false + } +} + +Set-Location $originalDir + +# Final summary +Write-Host "" +if ($allChecksPassed) { + Write-Host "=========================================" -ForegroundColor Green + Write-Host " CONGRATULATIONS! ALL SCENARIOS PASSED!" -ForegroundColor Green + Write-Host "=========================================" -ForegroundColor Green + Write-Host "`nYou've mastered git revert!" -ForegroundColor Cyan + Write-Host "You now understand:" -ForegroundColor Cyan + Write-Host " ✓ Reverting regular commits safely" -ForegroundColor White + Write-Host " ✓ Reverting merge commits with -m flag" -ForegroundColor White + Write-Host " ✓ Reverting multiple commits at once" -ForegroundColor White + Write-Host " ✓ Preserving history while undoing changes" -ForegroundColor White + Write-Host "`nReady for Module 06: Git Reset!" -ForegroundColor Green + Write-Host "" + exit 0 +} else { + Write-Host "[SUMMARY] Some checks failed. Review the hints above and try again." -ForegroundColor Red + Write-Host "[INFO] You can run this verification script as many times as needed." -ForegroundColor Yellow + Write-Host "" + exit 1 +} diff --git a/01_essentials/06-reset/README.md b/01_essentials/06-reset/README.md new file mode 100644 index 0000000..7cd2862 --- /dev/null +++ b/01_essentials/06-reset/README.md @@ -0,0 +1,717 @@ +# Module 06: Git Reset - Dangerous History Rewriting + +## ⚠️ CRITICAL SAFETY WARNING ⚠️ + +**Git reset is DESTRUCTIVE and DANGEROUS when misused!** + +Before using `git reset`, always ask yourself: + +``` +Have I pushed these commits to a remote repository? +├─ YES → ❌ DO NOT USE RESET! +│ Use git revert instead (Module 05) +│ Rewriting pushed history breaks collaboration! +│ +└─ NO → ✅ Proceed with reset (local cleanup only) + Choose your mode carefully: + --soft (safest), --mixed (moderate), --hard (DANGEROUS) +``` + +**The Golden Rule:** NEVER reset commits that have been pushed/shared. + +## About This Module + +Welcome to Module 06, where you'll learn the powerful but dangerous `git reset` command. Unlike `git revert` (Module 05) which safely creates new commits, **reset erases commits from history**. + +**Why reset exists:** +- ✅ Clean up messy local commit history before pushing +- ✅ Undo commits you haven't shared yet +- ✅ Unstage files from the staging area +- ✅ Recover from mistakes (with reflog) + +**Why reset is dangerous:** +- ⚠️ Erases commits permanently (without reflog) +- ⚠️ Breaks repositories if used on pushed commits +- ⚠️ Can lose work if used incorrectly +- ⚠️ Confuses teammates if they have your commits + +**Key principle:** Reset is for polishing LOCAL history before sharing. + +## Learning Objectives + +By completing this module, you will: + +1. Understand the three reset modes: --soft, --mixed, --hard +2. Reset commits while keeping changes staged (--soft) +3. Reset commits and unstage changes (--mixed) +4. Reset commits and discard everything (--hard) +5. Know when reset is appropriate (local only!) +6. Understand when to use revert instead +7. Use reflog to recover from mistakes + +## Prerequisites + +Before starting this module, you should: +- Be comfortable with commits and staging (`git add`, `git commit`) +- Understand `git revert` from Module 05 +- **Know the difference between local and pushed commits!** + +## Setup + +Run the setup script to create the challenge environment: + +```powershell +./setup.ps1 +``` + +This creates a `challenge/` directory with three branches demonstrating different reset modes: +- `soft-reset` - Reset with --soft (keep changes staged) +- `mixed-reset` - Reset with --mixed (unstage changes) +- `hard-reset` - Reset with --hard (discard everything) + +**Remember:** These are all LOCAL commits that have NEVER been pushed! + +## Understanding Reset Modes + +Git reset has three modes that control what happens to your changes: + +| Mode | Commits | Staging Area | Working Directory | +|------|---------|--------------|-------------------| +| **--soft** | ✂️ Removed | ✅ Kept (staged) | ✅ Kept | +| **--mixed** (default) | ✂️ Removed | ✂️ Cleared | ✅ Kept (unstaged) | +| **--hard** | ✂️ Removed | ✂️ Cleared | ✂️ **LOST!** | + +**Visual explanation:** + +``` +Before reset (3 commits): +A → B → C → HEAD + +After git reset --soft HEAD~1: +A → B → HEAD + ↑ + C's changes are staged + +After git reset --mixed HEAD~1 (or just git reset HEAD~1): +A → B → HEAD + ↑ + C's changes are unstaged (in working directory) + +After git reset --hard HEAD~1: +A → B → HEAD + ↑ + C's changes are GONE (discarded completely!) +``` + +## Challenge 1: Soft Reset (Safest) + +### Scenario + +You committed "feature C" but immediately realized the implementation is wrong. You want to undo the commit but keep the changes staged so you can edit and re-commit them properly. + +**Use case:** Fixing the last commit's message or contents. + +### Your Task + +1. Navigate to the challenge directory: + ```bash + cd challenge + ``` + +2. You should be on the `soft-reset` branch. View the commits: + ```bash + git log --oneline + ``` + + You should see: + - "Add feature C - needs better implementation!" + - "Add feature B" + - "Add feature A" + - "Initial project setup" + +3. View the current state: + ```bash + git status + # Should be clean + ``` + +4. Reset the last commit with --soft: + ```bash + git reset --soft HEAD~1 + ``` + +5. Check what happened: + ```bash + # Commit is gone + git log --oneline + # Should only show 3 commits now (feature C commit removed) + + # Changes are still staged + git status + # Should show "Changes to be committed" + + # View the staged changes + git diff --cached + # Should show feature C code ready to be re-committed + ``` + +### What to Observe + +After `--soft` reset: +- ✅ Commit removed from history +- ✅ Changes remain in staging area +- ✅ Working directory unchanged +- ✅ Ready to edit and re-commit + +**When to use --soft:** +- Fix the last commit message (though `commit --amend` is simpler) +- Combine multiple commits into one +- Re-do a commit with better changes + +## Challenge 2: Mixed Reset (Default, Moderate) + +### Scenario + +You committed two experimental features that aren't ready. You want to remove both commits and have the changes back in your working directory (unstaged) so you can review and selectively re-commit them. + +**Use case:** Undoing commits and starting over with more careful staging. + +### Your Task + +1. Switch to the mixed-reset branch: + ```bash + git switch mixed-reset + ``` + +2. View the commits: + ```bash + git log --oneline + ``` + + You should see: + - "Add debug mode - REMOVE THIS TOO!" + - "Add experimental feature X - REMOVE THIS!" + - "Add logging system" + - "Add application lifecycle" + +3. Reset the last TWO commits (default is --mixed): + ```bash + git reset HEAD~2 + # This is equivalent to: git reset --mixed HEAD~2 + ``` + +4. Check what happened: + ```bash + # Commits are gone + git log --oneline + # Should only show 2 commits (lifecycle + logging) + + # NO staged changes + git diff --cached + # Should be empty + + # Changes are in working directory (unstaged) + git status + # Should show "Changes not staged for commit" + + # View the unstaged changes + git diff + # Should show experimental and debug code + ``` + +### What to Observe + +After `--mixed` reset (the default): +- ✅ Commits removed from history +- ✅ Staging area cleared +- ✅ Changes moved to working directory (unstaged) +- ✅ Can selectively stage and re-commit parts + +**When to use --mixed (default):** +- Undo commits and start over with clean staging +- Split one large commit into multiple smaller ones +- Review changes before re-committing +- Most common reset mode for cleanup + +## Challenge 3: Hard Reset (MOST DANGEROUS!) + +### ⚠️ EXTREME CAUTION REQUIRED ⚠️ + +**This will PERMANENTLY DELETE your work!** + +Only use `--hard` when you're absolutely sure you want to throw away changes. + +### Scenario + +You committed completely broken code that you want to discard entirely. There's no salvaging it—you just want it gone. + +**Use case:** Throwing away failed experiments or completely wrong code. + +### Your Task + +1. Switch to the hard-reset branch: + ```bash + git switch hard-reset + ``` + +2. View the commits and the broken code: + ```bash + git log --oneline + # Shows "Add broken helper D - DISCARD COMPLETELY!" + + cat utils.py + # Shows the broken helper_d function + ``` + +3. Reset the last commit with --hard: + ```bash + git reset --hard HEAD~1 + ``` + + **WARNING:** This will permanently discard all changes from that commit! + +4. Check what happened: + ```bash + # Commit is gone + git log --oneline + # Should only show 2 commits + + # NO staged changes + git diff --cached + # Empty + + # NO unstaged changes + git diff + # Empty + + # Working directory clean + git status + # "nothing to commit, working tree clean" + + # File doesn't have broken code + cat utils.py + # helper_d is completely gone + ``` + +### What to Observe + +After `--hard` reset: +- ✅ Commit removed from history +- ✅ Staging area cleared +- ✅ Working directory reset to match +- ⚠️ All changes from that commit PERMANENTLY DELETED + +**When to use --hard:** +- Discarding failed experiments completely +- Throwing away work you don't want (CAREFUL!) +- Cleaning up after mistakes (use reflog to recover if needed) +- Resetting to a known good state + +**⚠️ WARNING:** Files in the discarded commit are NOT gone forever—they're still in reflog for about 90 days. See "Recovery with Reflog" section below. + +## Understanding HEAD~N Syntax + +When resetting, you specify where to reset to: + +```bash +# Reset to the commit before HEAD +git reset HEAD~1 + +# Reset to 2 commits before HEAD +git reset HEAD~2 + +# Reset to 3 commits before HEAD +git reset HEAD~3 + +# Reset to a specific commit hash +git reset abc123 + +# Reset to a branch +git reset main +``` + +**Visualization:** + +``` +HEAD~3 HEAD~2 HEAD~1 HEAD + ↓ ↓ ↓ ↓ +A → B → C → D → E + ↑ + Current commit +``` + +- `git reset HEAD~1` moves HEAD from E to D +- `git reset HEAD~2` moves HEAD from E to C +- `git reset abc123` moves HEAD to that specific commit + +## Verification + +Verify your solutions by running the verification script: + +```bash +cd .. # Return to module directory +./verify.ps1 +``` + +The script checks that: +- ✅ Commits were reset (count decreased) +- ✅ --soft: Changes remain staged +- ✅ --mixed: Changes are unstaged +- ✅ --hard: Everything is clean + +## Recovery with Reflog + +**Good news:** Even `--hard` reset doesn't immediately destroy commits! + +Git keeps a "reflog" (reference log) of where HEAD has been for about 90 days. You can use this to recover "lost" commits. + +### How to Recover from a Reset + +1. View the reflog: + ```bash + git reflog + ``` + + Output example: + ``` + abc123 HEAD@{0}: reset: moving to HEAD~1 + def456 HEAD@{1}: commit: Add broken helper D + ... + ``` + +2. Find the commit you want to recover (def456 in this example) + +3. Reset back to it: + ```bash + git reset def456 + # Or use the reflog reference: + git reset HEAD@{1} + ``` + +4. Your "lost" commit is back! + +### Reflog Safety Net + +**Important:** +- Reflog entries expire after ~90 days (configurable) +- Reflog is LOCAL to your repository (not shared) +- `git gc` can clean up old reflog entries +- If you really lose a commit, check reflog first! + +**Pro tip:** Before doing dangerous operations, note your current commit hash: +```bash +git log --oneline | head -1 +# abc123 Current work +``` + +## When to Use Git Reset + +Use `git reset` when: + +- ✅ **Commits are LOCAL only** (never pushed) +- ✅ **Cleaning up messy history** before sharing +- ✅ **Undoing recent commits** you don't want +- ✅ **Combining commits** into one clean commit +- ✅ **Unstaging files** (mixed mode) +- ✅ **Polishing commit history** before pull request + +**Golden Rule:** Only reset commits that are local to your machine! + +## When NOT to Use Git Reset + +DO NOT use `git reset` when: + +- ❌ **Commits are pushed/shared** with others +- ❌ **Teammates have your commits** (breaks their repos) +- ❌ **In public repositories** (use revert instead) +- ❌ **Unsure if pushed** (check `git log origin/main`) +- ❌ **On main/master branch** after push +- ❌ **Need audit trail** of changes + +**Use git revert instead** (Module 05) for pushed commits! + +## Decision Tree: Reset vs Revert + +``` +Need to undo a commit? +│ +├─ Have you pushed this commit? +│ │ +│ ├─ YES → Use git revert (Module 05) +│ │ Safe for shared history +│ │ Preserves complete audit trail +│ │ +│ └─ NO → Can use git reset (local only) +│ │ +│ ├─ Want to keep changes? +│ │ │ +│ │ ├─ Keep staged → git reset --soft +│ │ └─ Keep unstaged → git reset --mixed +│ │ +│ └─ Discard everything? → git reset --hard +│ (CAREFUL!) +``` + +## Reset vs Revert vs Rebase + +| Command | History | Safety | Use Case | +|---------|---------|--------|----------| +| **reset** | Erases | ⚠️ Dangerous | Local cleanup before push | +| **revert** | Preserves | ✅ Safe | Undo pushed commits | +| **rebase** | Rewrites | ⚠️ Dangerous | Polish history before push | + +**This module teaches reset.** You learned revert in Module 05. + +## Command Reference + +### Basic Reset + +```bash +# Reset last commit, keep changes staged +git reset --soft HEAD~1 + +# Reset last commit, unstage changes (default) +git reset HEAD~1 +git reset --mixed HEAD~1 # Same as above + +# Reset last commit, discard everything (DANGEROUS!) +git reset --hard HEAD~1 + +# Reset multiple commits +git reset --soft HEAD~3 # Last 3 commits + +# Reset to specific commit +git reset --soft abc123 +``` + +### Unstaging Files + +```bash +# Unstage a specific file (common use of reset) +git reset HEAD filename.txt + +# Unstage all files +git reset HEAD . + +# This is the same as: +git restore --staged filename.txt # Modern syntax +``` + +### Reflog and Recovery + +```bash +# View reflog +git reflog + +# Recover from reset +git reset --hard HEAD@{1} +git reset --hard abc123 +``` + +### Check Before Reset + +```bash +# Check if commits are pushed +git log origin/main..HEAD +# If output is empty, commits are pushed (DO NOT RESET) +# If output shows commits, they're local (safe to reset) + +# Another way to check +git log --oneline --graph --all +# Look for origin/main marker +``` + +## Common Mistakes + +### 1. Resetting Pushed Commits + +```bash +# ❌ NEVER do this if you've pushed! +git push +# ... time passes ... +git reset --hard HEAD~3 # BREAKS teammate repos! + +# ✅ Do this instead +git revert HEAD~3..HEAD # Safe for shared history +``` + +### 2. Using --hard Without Thinking + +```bash +# ❌ Dangerous - loses work! +git reset --hard HEAD~1 + +# ✅ Better - keep changes to review +git reset --mixed HEAD~1 +# Now you can review changes and decide +``` + +### 3. Resetting Without Checking If Pushed + +```bash +# ❌ Risky - are these commits pushed? +git reset HEAD~5 + +# ✅ Check first +git log origin/main..HEAD # Local commits only +git reset HEAD~5 # Now safe if output showed commits +``` + +### 4. Forgetting Reflog Exists + +```bash +# ❌ Panic after accidental --hard reset +# "I lost my work!" + +# ✅ Check reflog first! +git reflog # Find the "lost" commit +git reset --hard HEAD@{1} # Recover it +``` + +## Best Practices + +1. **Always check if commits are pushed before reset:** + ```bash + git log origin/main..HEAD + ``` + +2. **Prefer --mixed over --hard:** + - You can always discard changes later + - Hard to recover if you use --hard by mistake + +3. **Commit often locally, reset before push:** + - Make many small local commits + - Reset/squash into clean commits before pushing + +4. **Use descriptive commit messages even for local commits:** + - Helps when reviewing before reset + - Useful when checking reflog + +5. **Know your escape hatch:** + ```bash + git reflog # Your safety net! + ``` + +6. **Communicate with team:** + - NEVER reset shared branches (main, develop, etc.) + - Only reset your personal feature branches + - Only before pushing! + +## Troubleshooting + +### "I accidentally reset with --hard and lost work!" + +**Solution:** Check reflog: +```bash +git reflog +# Find the commit before your reset +git reset --hard HEAD@{1} # Or the commit hash +``` + +**Prevention:** Always use --mixed first, then discard if really needed. + +### "I reset but teammates still have my commits" + +**Problem:** You reset and pushed with --force after they pulled. + +**Impact:** Their repository is now broken/inconsistent. + +**Solution:** Communicate! They need to: +```bash +git fetch +git reset --hard origin/main # Or whatever branch +``` + +**Prevention:** NEVER reset pushed commits! + +### "Reset didn't do what I expected" + +**Issue:** Wrong mode or wrong HEAD~N count. + +**Solution:** Check current state: +```bash +git status +git diff +git diff --cached +git log --oneline +``` + +Undo the reset: +```bash +git reflog +git reset HEAD@{1} # Go back to before your reset +``` + +### "Can't reset - 'fatal: ambiguous argument HEAD~1'" + +**Issue:** No commits to reset (probably first commit). + +**Solution:** You can't reset before the first commit. If you want to remove the first commit entirely: +```bash +rm -rf .git # Nuclear option - deletes entire repo +git init # Start over +``` + +## Advanced: Reset Internals + +Understanding what reset does under the hood: + +```bash +# Reset moves the branch pointer +# Before: +main → A → B → C (HEAD) + +# After git reset --soft HEAD~1: +main → A → B (HEAD) + ↑ + C still exists in reflog, just not in branch history + +# The commit object C is still in .git/objects +# It's just unreachable from any branch +``` + +**Key insight:** Reset moves the HEAD and branch pointers backward. The commits still exist temporarily in reflog until garbage collection. + +## Going Further + +Now that you understand reset, you're ready for: + +- **Module 07: Git Stash** - Temporarily save uncommitted work +- **Module 08: Multiplayer Git** - Collaborate with complex workflows +- **Interactive Rebase** - Advanced history polishing (beyond this workshop) + +## Summary + +You've learned: + +- ✅ `git reset` rewrites history by moving HEAD backward +- ✅ `--soft` keeps changes staged (safest) +- ✅ `--mixed` (default) unstages changes +- ✅ `--hard` discards everything (most dangerous) +- ✅ NEVER reset pushed/shared commits +- ✅ Use reflog to recover from mistakes +- ✅ Check if commits are pushed before resetting +- ✅ Use revert (Module 05) for shared commits + +**The Critical Rule:** Reset is for LOCAL commits ONLY. Once you push, use revert! + +## Next Steps + +1. Complete all three challenge scenarios +2. Run `./verify.ps1` to check your solutions +3. Practice checking if commits are pushed before reset +4. Move on to Module 07: Git Stash + +--- + +**⚠️ FINAL REMINDER ⚠️** + +**Before any `git reset` command, ask yourself:** + +> "Have I pushed these commits?" + +If YES → Use `git revert` instead! + +If NO → Proceed carefully, choose the right mode. + +**When in doubt, use --mixed instead of --hard!** diff --git a/01_essentials/06-reset/reset.ps1 b/01_essentials/06-reset/reset.ps1 new file mode 100644 index 0000000..4cdc736 --- /dev/null +++ b/01_essentials/06-reset/reset.ps1 @@ -0,0 +1,24 @@ +#!/usr/bin/env pwsh +<# +.SYNOPSIS + Resets the Module 06 challenge environment to start fresh. + +.DESCRIPTION + This script removes the challenge directory and re-runs setup.ps1 + to create a fresh challenge environment. +#> + +Write-Host "`n=== Resetting Module 06: Git Reset Challenge ===" -ForegroundColor Cyan + +# Check if challenge directory exists +if (Test-Path "challenge") { + Write-Host "Removing existing challenge directory..." -ForegroundColor Yellow + Remove-Item -Recurse -Force "challenge" + Write-Host "[OK] Challenge directory removed" -ForegroundColor Green +} else { + Write-Host "[INFO] No existing challenge directory found" -ForegroundColor Yellow +} + +# Run setup to create fresh environment +Write-Host "`nRunning setup to create fresh challenge environment..." -ForegroundColor Cyan +& "$PSScriptRoot/setup.ps1" diff --git a/01_essentials/06-reset/setup.ps1 b/01_essentials/06-reset/setup.ps1 new file mode 100644 index 0000000..52ebf47 --- /dev/null +++ b/01_essentials/06-reset/setup.ps1 @@ -0,0 +1,348 @@ +#!/usr/bin/env pwsh +<# +.SYNOPSIS + Sets up the Module 06 challenge environment for learning git reset. + +.DESCRIPTION + This script creates a challenge directory with three branches demonstrating + different reset scenarios: + - soft-reset: Reset with --soft (keeps changes staged) + - mixed-reset: Reset with --mixed (unstages changes) + - hard-reset: Reset with --hard (discards everything) + reflog recovery +#> + +Write-Host "`n=== Setting up Module 06: Git Reset Challenge ===" -ForegroundColor Cyan +Write-Host "⚠️ WARNING: Git reset is DANGEROUS - use with extreme caution! ⚠️" -ForegroundColor Red + +# Remove existing challenge directory if it exists +if (Test-Path "challenge") { + Write-Host "Removing existing challenge directory..." -ForegroundColor Yellow + Remove-Item -Recurse -Force "challenge" +} + +# Create fresh challenge directory +Write-Host "Creating challenge directory..." -ForegroundColor Green +New-Item -ItemType Directory -Path "challenge" | Out-Null +Set-Location "challenge" + +# Initialize Git repository +Write-Host "Initializing Git repository..." -ForegroundColor Green +git init | Out-Null + +# Configure git for this repository +git config user.name "Workshop Student" +git config user.email "student@example.com" + +# ============================================================================ +# Create initial commit (shared by all scenarios) +# ============================================================================ +$readmeContent = @" +# Git Reset Practice + +This repository contains practice scenarios for learning git reset. +"@ +Set-Content -Path "README.md" -Value $readmeContent +git add . +git commit -m "Initial commit" | Out-Null + +# ============================================================================ +# SCENARIO 1: Soft Reset (--soft) +# ============================================================================ +Write-Host "`nScenario 1: Creating soft-reset branch..." -ForegroundColor Cyan + +# Create soft-reset branch from initial commit +git switch -c soft-reset | Out-Null + +# Build up scenario 1 commits +$projectContent = @" +# project.py - Main project file + +def initialize(): + """Initialize the project.""" + print("Project initialized") + +def main(): + initialize() + print("Running application...") +"@ +Set-Content -Path "project.py" -Value $projectContent +git add . +git commit -m "Initial project setup" | Out-Null + +# Good commit: Add feature A +$projectContent = @" +# project.py - Main project file + +def initialize(): + """Initialize the project.""" + print("Project initialized") + +def feature_a(): + """Feature A implementation.""" + print("Feature A is working") + +def main(): + initialize() + feature_a() + print("Running application...") +"@ +Set-Content -Path "project.py" -Value $projectContent +git add . +git commit -m "Add feature A" | Out-Null + +# Good commit: Add feature B +$projectContent = @" +# project.py - Main project file + +def initialize(): + """Initialize the project.""" + print("Project initialized") + +def feature_a(): + """Feature A implementation.""" + print("Feature A is working") + +def feature_b(): + """Feature B implementation.""" + print("Feature B is working") + +def main(): + initialize() + feature_a() + feature_b() + print("Running application...") +"@ +Set-Content -Path "project.py" -Value $projectContent +git add . +git commit -m "Add feature B" | Out-Null + +# BAD commit: Add feature C (wrong implementation) +$projectContent = @" +# project.py - Main project file + +def initialize(): + """Initialize the project.""" + print("Project initialized") + +def feature_a(): + """Feature A implementation.""" + print("Feature A is working") + +def feature_b(): + """Feature B implementation.""" + print("Feature B is working") + +def feature_c(): + """Feature C implementation - WRONG!""" + print("Feature C has bugs!") # This needs to be re-implemented + +def main(): + initialize() + feature_a() + feature_b() + feature_c() + print("Running application...") +"@ +Set-Content -Path "project.py" -Value $projectContent +git add . +git commit -m "Add feature C - needs better implementation!" | Out-Null + +Write-Host "[CREATED] soft-reset branch with commit to reset --soft" -ForegroundColor Green + +# ============================================================================ +# SCENARIO 2: Mixed Reset (--mixed, default) +# ============================================================================ +Write-Host "`nScenario 2: Creating mixed-reset branch..." -ForegroundColor Cyan + +# Switch back to initial commit and create mixed-reset branch +git switch main | Out-Null +git switch -c mixed-reset | Out-Null + +# Build up scenario 2 commits +$appContent = @" +# app.py - Application entry point + +def start(): + """Start the application.""" + print("Application started") + +def stop(): + """Stop the application.""" + print("Application stopped") +"@ +Set-Content -Path "app.py" -Value $appContent +git add . +git commit -m "Add application lifecycle" | Out-Null + +# Good commit: Add logging +$appContent = @" +# app.py - Application entry point + +def log(message): + """Log a message.""" + print(f"[LOG] {message}") + +def start(): + """Start the application.""" + log("Application started") + +def stop(): + """Stop the application.""" + log("Application stopped") +"@ +Set-Content -Path "app.py" -Value $appContent +git add . +git commit -m "Add logging system" | Out-Null + +# BAD commit 1: Add experimental feature X +$appContent = @" +# app.py - Application entry point + +def log(message): + """Log a message.""" + print(f"[LOG] {message}") + +def experimental_feature_x(): + """Experimental feature - NOT READY!""" + log("Feature X is experimental and buggy") + +def start(): + """Start the application.""" + log("Application started") + experimental_feature_x() + +def stop(): + """Stop the application.""" + log("Application stopped") +"@ +Set-Content -Path "app.py" -Value $appContent +git add . +git commit -m "Add experimental feature X - REMOVE THIS!" | Out-Null + +# BAD commit 2: Add debug mode (also not ready) +$appContent = @" +# app.py - Application entry point + +DEBUG_MODE = True # Should not be committed! + +def log(message): + """Log a message.""" + print(f"[LOG] {message}") + +def experimental_feature_x(): + """Experimental feature - NOT READY!""" + log("Feature X is experimental and buggy") + +def start(): + """Start the application.""" + if DEBUG_MODE: + log("DEBUG MODE ACTIVE!") + log("Application started") + experimental_feature_x() + +def stop(): + """Stop the application.""" + log("Application stopped") +"@ +Set-Content -Path "app.py" -Value $appContent +git add . +git commit -m "Add debug mode - REMOVE THIS TOO!" | Out-Null + +Write-Host "[CREATED] mixed-reset branch with commits to reset --mixed" -ForegroundColor Green + +# ============================================================================ +# SCENARIO 3: Hard Reset (--hard) + Reflog Recovery +# ============================================================================ +Write-Host "`nScenario 3: Creating hard-reset branch..." -ForegroundColor Cyan + +# Switch back to main and create hard-reset branch +git switch main | Out-Null +git switch -c hard-reset | Out-Null + +# Reset to basic state +$utilsContent = @" +# utils.py - Utility functions + +def helper_a(): + """Helper function A.""" + return "Helper A" + +def helper_b(): + """Helper function B.""" + return "Helper B" +"@ +Set-Content -Path "utils.py" -Value $utilsContent +git add . +git commit -m "Add utility helpers" | Out-Null + +# Good commit: Add helper C +$utilsContent = @" +# utils.py - Utility functions + +def helper_a(): + """Helper function A.""" + return "Helper A" + +def helper_b(): + """Helper function B.""" + return "Helper B" + +def helper_c(): + """Helper function C.""" + return "Helper C" +"@ +Set-Content -Path "utils.py" -Value $utilsContent +git add . +git commit -m "Add helper C" | Out-Null + +# BAD commit: Add broken helper D (completely wrong) +$utilsContent = @" +# utils.py - Utility functions + +def helper_a(): + """Helper function A.""" + return "Helper A" + +def helper_b(): + """Helper function B.""" + return "Helper B" + +def helper_c(): + """Helper function C.""" + return "Helper C" + +def helper_d(): + """COMPLETELY BROKEN - throw away!""" + # This is all wrong and needs to be discarded + broken_code = "This doesn't even make sense" + return broken_code.nonexistent_method() # Will crash! +"@ +Set-Content -Path "utils.py" -Value $utilsContent +git add . +git commit -m "Add broken helper D - DISCARD COMPLETELY!" | Out-Null + +Write-Host "[CREATED] hard-reset branch with commit to reset --hard" -ForegroundColor Green + +# ============================================================================ +# Return to soft-reset to start +# ============================================================================ +git switch soft-reset | Out-Null + +# Return to module directory +Set-Location .. + +Write-Host "`n=== Setup Complete! ===`n" -ForegroundColor Green +Write-Host "Three reset scenarios have been created:" -ForegroundColor Cyan +Write-Host " 1. soft-reset - Reset --soft (keep changes staged)" -ForegroundColor White +Write-Host " 2. mixed-reset - Reset --mixed (unstage changes)" -ForegroundColor White +Write-Host " 3. hard-reset - Reset --hard (discard everything) + reflog recovery" -ForegroundColor White +Write-Host "`n⚠️ CRITICAL SAFETY REMINDER ⚠️" -ForegroundColor Red +Write-Host "NEVER use git reset on commits that have been PUSHED!" -ForegroundColor Red +Write-Host "These scenarios are LOCAL ONLY for practice." -ForegroundColor Yellow +Write-Host "`nYou are currently on the 'soft-reset' branch." -ForegroundColor Cyan +Write-Host "`nNext steps:" -ForegroundColor Cyan +Write-Host " 1. cd challenge" -ForegroundColor White +Write-Host " 2. Read the README.md for detailed instructions" -ForegroundColor White +Write-Host " 3. Complete each reset challenge" -ForegroundColor White +Write-Host " 4. Run '..\\verify.ps1' to check your solutions" -ForegroundColor White +Write-Host "" diff --git a/01_essentials/06-reset/verify.ps1 b/01_essentials/06-reset/verify.ps1 new file mode 100644 index 0000000..bb0f592 --- /dev/null +++ b/01_essentials/06-reset/verify.ps1 @@ -0,0 +1,231 @@ +#!/usr/bin/env pwsh +<# +.SYNOPSIS + Verifies the Module 06 challenge solutions. + +.DESCRIPTION + Checks that all three reset scenarios have been completed correctly: + - soft-reset: Commit reset but changes remain staged + - mixed-reset: Commits reset and changes unstaged + - hard-reset: Everything reset and discarded +#> + +Write-Host "`n=== Verifying Module 06: Git Reset Solutions ===" -ForegroundColor Cyan +Write-Host "⚠️ Remember: NEVER reset pushed commits! ⚠️" -ForegroundColor Red + +$allChecksPassed = $true +$originalDir = Get-Location + +# Check if challenge directory exists +if (-not (Test-Path "challenge")) { + Write-Host "[FAIL] Challenge directory not found. Run setup.ps1 first." -ForegroundColor Red + exit 1 +} + +Set-Location "challenge" + +# Check if git repository exists +if (-not (Test-Path ".git")) { + Write-Host "[FAIL] Not a git repository. Run setup.ps1 first." -ForegroundColor Red + Set-Location $originalDir + exit 1 +} + +# ============================================================================ +# SCENARIO 1: Soft Reset Verification +# ============================================================================ +Write-Host "`n=== Scenario 1: Soft Reset ===`n" -ForegroundColor Cyan + +git switch soft-reset 2>&1 | Out-Null + +if ($LASTEXITCODE -ne 0) { + Write-Host "[FAIL] soft-reset branch not found" -ForegroundColor Red + $allChecksPassed = $false +} else { + # Count commits (should be 4: Initial + project setup + feature A + feature B) + $commitCount = [int](git rev-list --count HEAD 2>$null) + + if ($commitCount -eq 4) { + Write-Host "[PASS] Commit count is 4 (feature C commit was reset)" -ForegroundColor Green + } else { + Write-Host "[FAIL] Expected 4 commits, found $commitCount" -ForegroundColor Red + Write-Host "[HINT] Use: git reset --soft HEAD~1" -ForegroundColor Yellow + $allChecksPassed = $false + } + + # Check if changes are staged + $stagedChanges = git diff --cached --name-only 2>$null + if ($stagedChanges) { + Write-Host "[PASS] Changes are staged (feature C code in staging area)" -ForegroundColor Green + + # Verify the staged changes contain feature C code + $stagedContent = git diff --cached 2>$null + if ($stagedContent -match "feature_c") { + Write-Host "[PASS] Staged changes contain feature C code" -ForegroundColor Green + } else { + Write-Host "[INFO] Staged changes don't seem to contain feature C" -ForegroundColor Yellow + } + } else { + Write-Host "[FAIL] No staged changes found" -ForegroundColor Red + Write-Host "[HINT] After --soft reset, changes should remain staged" -ForegroundColor Yellow + $allChecksPassed = $false + } + + # Check working directory has no unstaged changes to tracked files + $unstagedChanges = git diff --name-only 2>$null + if (-not $unstagedChanges) { + Write-Host "[PASS] No unstaged changes (all changes are staged)" -ForegroundColor Green + } else { + Write-Host "[INFO] Found unstaged changes (expected only staged changes)" -ForegroundColor Yellow + } +} + +# ============================================================================ +# SCENARIO 2: Mixed Reset Verification +# ============================================================================ +Write-Host "`n=== Scenario 2: Mixed Reset ===`n" -ForegroundColor Cyan + +git switch mixed-reset 2>&1 | Out-Null + +if ($LASTEXITCODE -ne 0) { + Write-Host "[FAIL] mixed-reset branch not found" -ForegroundColor Red + $allChecksPassed = $false +} else { + # Count commits (should be 3: Initial + lifecycle + logging, bad commits removed) + $commitCount = [int](git rev-list --count HEAD 2>$null) + + if ($commitCount -eq 3) { + Write-Host "[PASS] Commit count is 3 (both bad commits were reset)" -ForegroundColor Green + } elseif ($commitCount -eq 4) { + Write-Host "[INFO] Commit count is 4 (one commit reset, need to reset one more)" -ForegroundColor Yellow + Write-Host "[HINT] Use: git reset HEAD~1 (or git reset --mixed HEAD~1)" -ForegroundColor Yellow + $allChecksPassed = $false + } else { + Write-Host "[FAIL] Expected 3 commits, found $commitCount" -ForegroundColor Red + Write-Host "[HINT] Use: git reset --mixed HEAD~2 to remove both bad commits" -ForegroundColor Yellow + $allChecksPassed = $false + } + + # Check that there are NO staged changes + $stagedChanges = git diff --cached --name-only 2>$null + if (-not $stagedChanges) { + Write-Host "[PASS] No staged changes (--mixed unstages everything)" -ForegroundColor Green + } else { + Write-Host "[FAIL] Found staged changes (--mixed should unstage)" -ForegroundColor Red + Write-Host "[HINT] After --mixed reset, changes should be unstaged" -ForegroundColor Yellow + $allChecksPassed = $false + } + + # Check that there ARE unstaged changes in working directory + $unstagedChanges = git diff --name-only 2>$null + if ($unstagedChanges) { + Write-Host "[PASS] Unstaged changes present in working directory" -ForegroundColor Green + + # Verify unstaged changes contain the experimental/debug code + $workingContent = git diff 2>$null + if ($workingContent -match "experimental|DEBUG") { + Write-Host "[PASS] Unstaged changes contain the reset code" -ForegroundColor Green + } else { + Write-Host "[INFO] Unstaged changes don't contain expected code" -ForegroundColor Yellow + } + } else { + Write-Host "[FAIL] No unstaged changes found" -ForegroundColor Red + Write-Host "[HINT] After --mixed reset, changes should be in working directory (unstaged)" -ForegroundColor Yellow + $allChecksPassed = $false + } +} + +# ============================================================================ +# SCENARIO 3: Hard Reset Verification +# ============================================================================ +Write-Host "`n=== Scenario 3: Hard Reset ===`n" -ForegroundColor Cyan + +git switch hard-reset 2>&1 | Out-Null + +if ($LASTEXITCODE -ne 0) { + Write-Host "[FAIL] hard-reset branch not found" -ForegroundColor Red + $allChecksPassed = $false +} else { + # Count commits (should be 3: Initial + utilities + helper C, bad commit removed) + $commitCount = [int](git rev-list --count HEAD 2>$null) + + if ($commitCount -eq 3) { + Write-Host "[PASS] Commit count is 3 (broken commit was reset)" -ForegroundColor Green + } else { + Write-Host "[FAIL] Expected 3 commits, found $commitCount" -ForegroundColor Red + Write-Host "[HINT] Use: git reset --hard HEAD~1" -ForegroundColor Yellow + $allChecksPassed = $false + } + + # Check that there are NO staged changes + $stagedChanges = git diff --cached --name-only 2>$null + if (-not $stagedChanges) { + Write-Host "[PASS] No staged changes (--hard discards everything)" -ForegroundColor Green + } else { + Write-Host "[FAIL] Found staged changes (--hard should discard all)" -ForegroundColor Red + $allChecksPassed = $false + } + + # Check that there are NO unstaged changes + $unstagedChanges = git diff --name-only 2>$null + if (-not $unstagedChanges) { + Write-Host "[PASS] No unstaged changes (--hard discards everything)" -ForegroundColor Green + } else { + Write-Host "[FAIL] Found unstaged changes (--hard should discard all)" -ForegroundColor Red + $allChecksPassed = $false + } + + # Check working directory is clean + $statusOutput = git status --porcelain 2>$null + if (-not $statusOutput) { + Write-Host "[PASS] Working directory is completely clean" -ForegroundColor Green + } else { + Write-Host "[INFO] Working directory has some changes" -ForegroundColor Yellow + } + + # Verify the file doesn't have the broken code + if (Test-Path "utils.py") { + $utilsContent = Get-Content "utils.py" -Raw + if ($utilsContent -notmatch "helper_d") { + Write-Host "[PASS] Broken helper_d function is gone" -ForegroundColor Green + } else { + Write-Host "[FAIL] Broken helper_d still exists (wasn't reset)" -ForegroundColor Red + $allChecksPassed = $false + } + + if ($utilsContent -match "helper_c") { + Write-Host "[PASS] Good helper_c function is preserved" -ForegroundColor Green + } else { + Write-Host "[FAIL] Good helper_c function missing" -ForegroundColor Red + $allChecksPassed = $false + } + } +} + +Set-Location $originalDir + +# Final summary +Write-Host "" +if ($allChecksPassed) { + Write-Host "==========================================" -ForegroundColor Green + Write-Host " CONGRATULATIONS! ALL SCENARIOS PASSED!" -ForegroundColor Green + Write-Host "==========================================" -ForegroundColor Green + Write-Host "`nYou've mastered git reset!" -ForegroundColor Cyan + Write-Host "You now understand:" -ForegroundColor Cyan + Write-Host " ✓ Resetting commits with --soft (keep staged)" -ForegroundColor White + Write-Host " ✓ Resetting commits with --mixed (unstage)" -ForegroundColor White + Write-Host " ✓ Resetting commits with --hard (discard all)" -ForegroundColor White + Write-Host " ✓ The DANGER of reset on shared history" -ForegroundColor White + Write-Host "`n⚠️ CRITICAL REMINDER ⚠️" -ForegroundColor Red + Write-Host "NEVER use 'git reset' on commits you've already PUSHED!" -ForegroundColor Red + Write-Host "Always use 'git revert' (Module 05) for shared commits!" -ForegroundColor Yellow + Write-Host "`nReady for Module 07: Git Stash!" -ForegroundColor Green + Write-Host "" + exit 0 +} else { + Write-Host "[SUMMARY] Some checks failed. Review the hints above and try again." -ForegroundColor Red + Write-Host "[INFO] You can run this verification script as many times as needed." -ForegroundColor Yellow + Write-Host "[REMINDER] Reset is ONLY for local, un-pushed commits!" -ForegroundColor Yellow + Write-Host "" + exit 1 +} diff --git a/01_essentials/06-stash/README.md b/01_essentials/07-stash/README.md similarity index 100% rename from 01_essentials/06-stash/README.md rename to 01_essentials/07-stash/README.md diff --git a/01_essentials/06-stash/reset.ps1 b/01_essentials/07-stash/reset.ps1 similarity index 100% rename from 01_essentials/06-stash/reset.ps1 rename to 01_essentials/07-stash/reset.ps1 diff --git a/01_essentials/06-stash/setup.ps1 b/01_essentials/07-stash/setup.ps1 similarity index 100% rename from 01_essentials/06-stash/setup.ps1 rename to 01_essentials/07-stash/setup.ps1 diff --git a/01_essentials/06-stash/verify.ps1 b/01_essentials/07-stash/verify.ps1 similarity index 100% rename from 01_essentials/06-stash/verify.ps1 rename to 01_essentials/07-stash/verify.ps1 diff --git a/01_essentials/07-multiplayer/FACILITATOR-SETUP.md b/01_essentials/08-multiplayer/FACILITATOR-SETUP.md similarity index 100% rename from 01_essentials/07-multiplayer/FACILITATOR-SETUP.md rename to 01_essentials/08-multiplayer/FACILITATOR-SETUP.md diff --git a/01_essentials/07-multiplayer/README.md b/01_essentials/08-multiplayer/README.md similarity index 100% rename from 01_essentials/07-multiplayer/README.md rename to 01_essentials/08-multiplayer/README.md diff --git a/GIT-CHEATSHEET.md b/GIT-CHEATSHEET.md index 4755b5e..d8995a6 100644 --- a/GIT-CHEATSHEET.md +++ b/GIT-CHEATSHEET.md @@ -247,6 +247,16 @@ git revert --abort ``` Abort a revert in progress. +```bash +git revert -m 1 +``` +Revert a merge commit (requires -m flag to specify which parent to keep). Use `-m 1` to keep the branch you merged into (most common). + +```bash +git revert -m 2 +``` +Revert a merge commit but keep the branch that was merged in (rare). + ### Cherry-Pick ```bash diff --git a/README.md b/README.md index 7175f89..957191d 100644 --- a/README.md +++ b/README.md @@ -8,7 +8,7 @@ Perfect for developers who want to move beyond basic Git usage and master profes The workshop is organized into two tracks: -### 01 Essentials - Core Git Skills (7 modules) +### 01 Essentials - Core Git Skills (8 modules) Master fundamental Git concepts and collaborative workflows: @@ -16,9 +16,10 @@ Master fundamental Git concepts and collaborative workflows: - **Module 02: Viewing History** - Use git log and git diff to explore project history - **Module 03: Branching and Merging** - Create branches, merge them, and resolve conflicts (checkpoint-based) - **Module 04: Cherry-Pick** - Apply specific commits from one branch to another -- **Module 05: Reset vs Revert** - Understand when to rewrite history vs create new commits -- **Module 06: Stash** - Temporarily save work without committing -- **Module 07: Multiplayer Git** - **The Great Print Project** - Real cloud-based collaboration with teammates +- **Module 05: Git Revert** - Safe undoing - preserve history while reversing changes (includes merge commit reversion) +- **Module 06: Git Reset** - Dangerous history rewriting - local cleanup only (NEVER on pushed commits!) +- **Module 07: Stash** - Temporarily save work without committing +- **Module 08: Multiplayer Git** - **The Great Print Project** - Real cloud-based collaboration with teammates ### 02 Advanced - Professional Techniques (6 modules) @@ -44,18 +45,18 @@ Advanced Git workflows for power users: **Quick Reference**: See [GIT-CHEATSHEET.md](GIT-CHEATSHEET.md) for a comprehensive list of all Git commands covered in this workshop. Don't worry about memorizing everything - use this as a reference when you need to look up command syntax! -### For Module 07: Multiplayer Git +### For Module 08: Multiplayer Git **This module is different!** It uses a real Git server for authentic collaboration: -1. Navigate to `01_essentials/09-multiplayer` +1. Navigate to `01_essentials/08-multiplayer` 2. Read the `README.md` for complete instructions 3. **No setup script** - you'll clone from https://git.frod.dk/multiplayer 4. Work with a partner on shared branches 5. Experience real merge conflicts and pull requests 6. **No verify script** - success is visual (your code appears in the final output) -**Facilitators**: See `01_essentials/09-multiplayer/FACILITATOR-SETUP.md` for server setup and workshop guidance. +**Facilitators**: See `01_essentials/08-multiplayer/FACILITATOR-SETUP.md` for server setup and workshop guidance. ## Running PowerShell Scripts @@ -136,9 +137,9 @@ You should see your name and email printed. This is required to make commits in $PSVersionTable.PSVersion ``` -### Python (for Module 07 only) +### Python (for Module 08 only) -Module 07 (Multiplayer Git) uses Python: +Module 08 (Multiplayer Git) uses Python: - **Python 3.6+** required to run the Great Print Project - Check: `python --version` or `python3 --version` @@ -209,7 +210,7 @@ Follow the instructions in each module's README.md file. - **Progressive Difficulty**: Builds from basics to advanced Git techniques - **Reset Anytime**: Each local module includes a reset script for a fresh start - **Self-Paced**: Learn at your own speed with detailed README guides -- **Real Collaboration**: Module 07 uses an actual Git server for authentic teamwork +- **Real Collaboration**: Module 08 uses an actual Git server for authentic teamwork - **Comprehensive Coverage**: From `git init` to advanced rebasing and bisecting ## Learning Path @@ -305,7 +306,7 @@ Before distributing this workshop to attendees for self-study: 2. Each module's `challenge/` directory will become its own independent git repository when attendees run `setup.ps1` 3. This isolation ensures each module provides a clean learning environment -**Note**: Module 07 (Multiplayer) requires you to set up a Git server - see facilitator guide below. +**Note**: Module 08 (Multiplayer) requires you to set up a Git server - see facilitator guide below. ### Facilitated Workshop @@ -313,13 +314,13 @@ For running this as a full-day instructor-led workshop: 1. **See [WORKSHOP-AGENDA.md](WORKSHOP-AGENDA.md)** - Complete agenda with timing, activities, and facilitation tips 2. **See [PRESENTATION-OUTLINE.md](PRESENTATION-OUTLINE.md)** - Slide deck outline for presentations -3. **Workshop covers:** Essentials 01-05 + Module 07 (Multiplayer collaboration exercise) +3. **Workshop covers:** Essentials 01-05 + Module 08 (Multiplayer collaboration exercise) 4. **Duration:** 6-7 hours including breaks 5. **Format:** Mix of presentation, live demos, and hands-on challenges **Facilitator preparation:** - Review the workshop agenda thoroughly -- Set up Git server for Module 07 (see below) +- Set up Git server for Module 08 (see below) - Ensure all participants have prerequisites installed (Git, PowerShell, Python) - Prepare slides using the presentation outline - Test all modules on a clean machine @@ -327,9 +328,9 @@ For running this as a full-day instructor-led workshop: The workshop format combines instructor-led sessions with self-paced hands-on modules for an engaging learning experience. -### Setting Up Module 07: Multiplayer Git +### Setting Up Module 08: Multiplayer Git -Module 07 requires a Git server for authentic collaboration. You have two options: +Module 08 requires a Git server for authentic collaboration. You have two options: **Option 1: Self-Hosted Gitea Server (Recommended)** @@ -344,7 +345,7 @@ Run your own Git server with Gitea using Docker and Cloudflare Tunnel: **Setup:** 1. See [GITEA-SETUP.md](GITEA-SETUP.md) for complete Gitea + Docker + Cloudflare Tunnel instructions -2. See `01_essentials/09-multiplayer/FACILITATOR-SETUP.md` for detailed workshop preparation: +2. See `01_essentials/08-multiplayer/FACILITATOR-SETUP.md` for detailed workshop preparation: - Creating student accounts - Setting up The Great Print Project repository - Pairing students @@ -374,14 +375,15 @@ git-workshop/ ├── GITEA-SETUP.md # Self-hosted Git server setup ├── install-glow.ps1 # Install glow markdown renderer │ -├── 01_essentials/ # Core Git skills (7 modules) +├── 01_essentials/ # Core Git skills (8 modules) │ ├── 01-basics/ # Initialize, commit, status │ ├── 02-history/ # Log, diff, show │ ├── 03-branching-and-merging/ # Branches, merging, conflicts (checkpoint-based) │ ├── 04-cherry-pick/ # Apply specific commits -│ ├── 05-reset-vs-revert/ # Undo changes safely -│ ├── 06-stash/ # Save work-in-progress -│ └── 07-multiplayer/ # Real collaboration (cloud-based) +│ ├── 05-revert/ # Safe undoing (includes merge commits) +│ ├── 06-reset/ # Dangerous local cleanup +│ ├── 07-stash/ # Save work-in-progress +│ └── 08-multiplayer/ # Real collaboration (cloud-based) │ ├── README.md # Student guide │ └── FACILITATOR-SETUP.md # Server setup guide │ @@ -398,7 +400,7 @@ git-workshop/ ### The Great Print Project (Module 07) -Unlike any other Git tutorial, Module 07 provides **real collaborative experience**: +Unlike any other Git tutorial, Module 08 provides **real collaborative experience**: - **Real Git server**: Not simulated - actual cloud repository at https://git.frod.dk/multiplayer - **Real teammates**: Work in pairs on shared branches @@ -425,7 +427,7 @@ This is how professional developers actually work - no simulation, no shortcuts. **Q: Do I need to complete all modules?** A: No! Essentials 01-05 covers what most developers use daily. Complete 06-09 and Advanced modules to deepen your skills. -**Q: Can I do Module 07 (Multiplayer) without a partner?** +**Q: Can I do Module 08 (Multiplayer) without a partner?** A: Not recommended - collaboration is the point. If solo, skip to Advanced modules or wait until you can pair with someone. **Q: How long does the workshop take?** @@ -441,16 +443,16 @@ A: 2. Check [GIT-CHEATSHEET.md](GIT-CHEATSHEET.md) 3. Run `./reset.ps1` to start fresh 4. Use `git status` and `git log --graph` to understand current state -5. For Module 07, ask your partner or facilitator +5. For Module 08, ask your partner or facilitator **Q: Can I use this for a team workshop at my company?** A: Absolutely! See the "For Workshop Facilitators" section above. The materials are designed for both self-study and instructor-led workshops. **Q: Do I need internet access?** -A: Modules 01-08 work completely offline. Module 07 requires internet to access the Git server. +A: Modules 01-07 work completely offline. Module 08 requires internet to access the Git server. **Q: What if I prefer GitHub/GitLab instead of Gitea?** -A: The skills are identical across all Git platforms. Module 07 uses Gitea but everything you learn applies to GitHub, GitLab, Bitbucket, etc. +A: The skills are identical across all Git platforms. Module 08 uses Gitea but everything you learn applies to GitHub, GitLab, Bitbucket, etc. ---