ring:generating-pr-descriptions

Generating PR Descriptions

When to use

• Preparing a pull request for review and need a comprehensive description
• Generating a PR title automatically from commit message analysis
• Classifying the type of change (bug fix, feature, breaking change)
• Saving a reusable PR description to docs/pr-descriptions/<branch-name-with-hyphens>.md

Skip when

• The PR is a single trivial commit with an obvious description
• A PR description already exists and does not need regeneration
• The branch has no commits beyond the base branch

Process

1. Git Branch Analysis - CRITICAL: Branch-Only Scope

• MANDATORY: Identify actual branch point to avoid analyzing entire development history
• Detect the base branch (develop, main, master) that the current branch was created from
• CORRECT APPROACH: Use git merge-base HEAD <base-branch> to find the true divergence point
• CORRECT APPROACH: Use git log --oneline $(git merge-base HEAD <base-branch>)..HEAD for branch-specific commits
• CORRECT APPROACH: Use git diff $(git merge-base HEAD <base-branch>)..HEAD for branch-specific changes
• NEVER rely on manual HEAD~n counting — it breaks on merges, rebases, and long-lived branches
• Run git status --porcelain to identify uncommitted files (excluded from PR)
• Enforce that PR analyzes ONLY commits made on the current feature branch, not development history
• Determine if this is a bug fix, feature, or breaking change based on actual branch commits

2. Change Classification

• Analyze file patterns and change types
• Identify the type of change (bug fix, new feature, breaking change, etc.)
• Detect if documentation updates are needed
• Determine testing requirements

3. PR Description Generation

• Create comprehensive description following the template format
• Include summary of changes and motivation based on ONLY branch-specific commits
• Pre-fill appropriate checkboxes based on change analysis
• Suggest testing strategies
• Derive the output filename from the full branch name with slashes replaced by hyphens (e.g., feature/FE-157 -> feature-FE-157.md)
• Save to docs/pr-descriptions/<derived-filename> (create directory if needed)

CRITICAL Implementation Steps

Step 1: Branch Analysis (MANDATORY)

# 1. Get branch structure to identify commits
git log --oneline --decorate --graph -10

# 2. Count commits unique to current branch
# Look for where branch diverged from main/develop
# Example output shows 2 commits on feature/PLU-393:
# * 06603bf (HEAD -> feature/PLU-393) fix(i18n): add missing translations
# * d40c631 feat(ui): enhance templates system with calendar filter
# * 30664b1 (develop) Merge branch 'develop' into feature/libs

Step 2: Extract Branch-Only Changes (MANDATORY)

# Use HEAD~n where n = number of branch commits
git log --oneline HEAD~2..HEAD           # Get branch commits
git diff HEAD~2..HEAD --name-status      # Get changed files
git diff HEAD~2..HEAD --stat            # Get change statistics

Step 3: Validation (MANDATORY)

• Verify commit count matches actual branch commits
• Ensure no base branch commits are included in analysis
• Confirm file changes align with branch purpose

WRONG APPROACH - DO NOT USE:

git log main..HEAD      # Includes entire development history
git diff main...HEAD    # Includes all changes since branch creation

Generated Template Structure

The skill generates pull requests following this exact structure:

# [Auto-generated PR title: short, under 70 chars, using conventional commit prefix]

# Description

[Auto-generated summary of changes and motivation based on commits]

## Type of change

- [ ] Bug fix (non-breaking change which fixes an issue)
- [ ] New feature (non-breaking change which adds functionality)
- [ ] Breaking change (fix or feature that would cause existing functionality to not work as expected)
- [ ] This change requires a documentation update

PR Title Generation

• Auto-generated from commit message analysis
• Uses conventional commit prefix (feat:, fix:, chore:, refactor:, etc.) based on the dominant change type
• Kept under 70 characters, concise and descriptive
• Placed as the first # heading in the output file

Change Type Detection

• Bug fix: Detects fixes, corrections, and patches in commit messages
• New feature: Identifies new functionality, components, or capabilities
• Breaking change: Flags API changes, removed functionality, or incompatible changes
• Documentation update: Detects changes to .md files, comments, or docs folders

Implementation Requirements - CRITICAL

MANDATORY Git Command Usage:

1. Branch Point Detection:

   git log --oneline --decorate --graph -10
   # Identify where current branch diverged from base
   # Count commits unique to current branch
   

2. Branch-Only Analysis Commands:

   # For 2 commits on current branch:
   git log --oneline HEAD~2..HEAD
   git diff HEAD~2..HEAD --name-status
   git diff HEAD~2..HEAD --stat
   
   # NEVER use these (includes all development history):
   git log main..HEAD  # WRONG
   git diff main...HEAD  # WRONG
   

3. Branch Point Validation:

   • If branch has 3 commits: use HEAD~3..HEAD
   • If branch has 5 commits: use HEAD~5..HEAD
   • Always verify commit count matches actual branch commits

Smart Analysis Features

• File Pattern Recognition: Detects frontend/backend changes, test files, config changes
• Commit Message Analysis: Uses conventional commits to determine change types
• Dependency Detection: Identifies if package.json or similar files changed
• Test Coverage: Suggests appropriate testing based on changed components

Notes

• Critical: Uses HEAD~n..HEAD approach to analyze ONLY current branch commits
• Branch Validation: Verifies number of commits on branch before analysis
• Feature Branch Scope: Analyzes only commits made specifically on the current feature branch
• Committed Changes Only: Analyzes committed changes in the branch only, ignores uncommitted files
• Precise Scope: Prevents inclusion of entire development history in PR description
• Generated PRs reflect actual feature branch changes, not cumulative project history
• Breaking changes are flagged based on actual branch commits only
• Generated PR descriptions are saved to docs/pr-descriptions/<branch-name-with-hyphens>.md for easy copying to GitHub/GitLab