git-workshop/01-essentials/06-revert/setup.ps1

#!/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"

# Detect the default branch name after first commit (created below)
# Will be detected after the initial commit in SCENARIO 1

# ============================================================================
# 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

# Detect the main branch name after first commit
$mainBranch = git branch --show-current
if (-not $mainBranch) {
    $mainBranch = git config --get init.defaultBranch
    if (-not $mainBranch) { $mainBranch = "main" }
}
Write-Host "Default branch detected: $mainBranch" -ForegroundColor Yellow

# 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 $mainBranch | 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 $mainBranch | 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 ""