🚫 Auto Unapprove Reviews Action

GitHub Action for smart dismissal of pull request reviews when code owners modify files after approval or when reviewers approve their own changes.

Problem & My Solution

As a DevOps engineer working with large monorepos, I've often encountered a frustrating limitation in GitHub's PR review system. When new commits are pushed to a PR, GitHub only offers two options:

1. keep all approvals
2. dismiss all approvals. This binary choice becomes particularly problematic in monorepos where multiple teams own different parts of the codebase

To solve this, I developed a GitHub Action called "Auto Unapprove Reviews" that provides granular control over review dismissals. Here's how it works:

The action follows a simple but effective flow:

1. Get PR information
2. Check changed files
3. Check team ownership
4. Analyze review status
5. Take appropriate action

📁 File Structure

dismiss-reviews/
├── 🎯 **Core Files**
│   ├── src/index.js          # GitHub Action entry point
│   ├── action.yml            # Action definition
│   └── package.json          # Dependencies
│
├── 🚀 **Main Script**
│   └── auto-unapprove.js    # ⭐ Smart dismissal with stale detection
│
├── 📝 **Examples & Documentation**
│   ├── examples/basic-usage.md     # Usage examples and setup
│   └── examples/workflow-example.yml  # Sample GitHub Actions workflow
│
├── 🧪 **Demo & Testing**
│   └── test-team-info.js     # Demo of team information features
│
└── 📦 **Build Artifacts**
    └── dist/                 # Compiled action bundle

🚀 Main Script Features

auto-unapprove.js - Smart dismissal with advanced features:

• ✅ Stale approval detection - Dismisses approvals when files are modified after approval
• ✅ Team membership validation - Supports GitHub team-based code ownership
• ✅ Precise file matching - Only dismisses when owned files are actually modified
• ✅ Performance optimized - Parallel API calls and efficient caching
• ✅ Comprehensive logging - Detailed analysis and reasoning for each decision

🚀 Quick Start

Option 1: GitHub Action (Recommended)

- name: Smart dismiss reviews
  uses: ./
  with:
    github-token: ${{ secrets.GITHUB_TOKEN }}
    pr-number: ${{ github.event.number }}
    dry-run: 'false'
    code-owners-file: 'CODEOWNERS'  # Optional: custom path
    target-branch: ${{ github.event.pull_request.base.ref }}  # Optional: target branch
    team-start-with: '@'  # Optional: team prefix

Option 2: Direct Script

# Set environment variables
export GITHUB_TOKEN="your_token"
export PR_NUMBER="123"
export GITHUB_REPOSITORY="myorg/myrepo"

# Run smart dismissal
node auto-unapprove.js

🧠 How It Works

1. Get all changed files from the entire PR (not just latest commit)
2. Parse CODEOWNERS from the PR target branch (not default branch) using hierarchical path matching (most specific wins)
3. Check team memberships via GitHub API for relevant teams only
4. Analyze approval timeline - detect commits made after approval
5. Smart dismissal logic:
   • Dismiss code owners who authored commits
   • Dismiss stale approvals (post-approval commits to owned files)
   • Preserve legitimate approvals from non-owners

📝 Example Workflow

name: Auto Unapprove

on:
  pull_request:
    types: [synchronize]

jobs:
  auto-unapprove:
    runs-on: ubuntu-latest

    steps:
      - uses: actions/create-github-app-token@v1
        id: app-token
        with:
          app-id: ${{ vars.REVIEWS_APP_ID }}
          private-key: ${{ secrets.REVIEWS_APP_PRIVATE_KEY }}

      - name: Dismiss Stale Reviews
        uses: RotemK1/auto-unapprove@main
        with:
          github-token: ${{ steps.app-token.outputs.token }}
          pr-number: ${{ github.event.number }}
          dry-run: 'false'
          target-branch: ${{ github.event.pull_request.base.ref }}
          team-start-with: '@your-org/'

For more workflow examples, see example-workflow.yml

---

Required Permissions: for more info on how to use GitHub App token check https://github.com/actions/create-github-app-token

• Repository permissions:

  • Administration: Repository creation, deletion, settings, teams, and collaborators. (READ ONLY)
  • Contents: Repository contents, commits, branches, downloads, releases, and merges. (READ ONLY)
  • Pull requests: Pull requests and related comments, assignees, labels, milestones, and merges. (READ AND WRITE)

• Organization permissions:

  • Members: Organization members and teams

⚙️ Key Features

• ✅ Target branch CODEOWNERS: Reads ownership rules from PR target branch, not default branch
• ✅ Stale approval detection: Automatically detects and dismisses approvals made stale by subsequent commits
• ✅ Surgical precision: Only dismisses when owned files are actually modified
• ✅ Team support: Full GitHub team membership validation via API
• ✅ Timeline analysis: Compares approval timestamps with commit timestamps
• ✅ Hierarchical CODEOWNERS: Proper path matching with most-specific-wins logic
• ✅ Performance optimized: Parallel API calls and efficient team checking
• ✅ Comprehensive logging: Detailed reasoning for every dismissal decision
• ✅ Dry-run mode: Safe testing without actual dismissals

📊 Example Output

🚀 Smart Review Dismissal
   Repository: myorg/myrepo
   PR: #123
   Mode: 🧪 DRY RUN

📁 All changed files in PR (3):
   📝 src/gui/components/Button.tsx
   📝 src/gui/styles/theme.css  
   📝 src/gui/utils/helpers.ts

🎯 Target branch: main
👑 Parsed 15 CODEOWNERS rules

🎯 DISMISSAL ANALYSIS:
   🕐 Checking commits after jane-smith's approval (2025-06-04T12:49:59.000Z)...
     📅 Commit 55a4fc5 at 2025-06-04T12:53:44Z
       🎯 Modified owned files: src/gui/components/Button.tsx
   
   🚫 DISMISS @jane-smith
      📁 Files: src/gui/components/Button.tsx, src/gui/styles/theme.css, src/gui/utils/helpers.ts
      👑 Owner Via: @myorg/frontend-team
      💡 Reason: Approval became stale - commits modified owned files
   
   ✅ KEEP @bob-jones
      📄 Not owner of changed files

📊 EXECUTION PLAN:
   • Changed files: 3
   • Total approvals: 2
   • Dismissals needed: 1
   • Approvals preserved: 1

🔧 Inputs & Environment Variables

GitHub Action Inputs

Input	Required	Default	Description
github-token	✅	-	GitHub API token with repo access
pr-number	✅	-	Pull request number to analyze
dry-run	-	true	Set to 'false' for actual dismissals
code-owners-file	-	CODEOWNERS	Path to CODEOWNERS file
target-branch	-	main	Target branch to read CODEOWNERS from
team-start-with	-	@	Team prefix for organization

Environment Variables (Direct Script Usage)

Variable	Required	Default	Description
GITHUB_TOKEN	✅	-	GitHub API token with repo access
PR_NUMBER	✅	-	Pull request number to analyze
GITHUB_REPOSITORY	✅	-	Repository in owner/repo format
TEAM_START_WITH	-	@	Team prefix for organization
DRY_RUN	-	true	Set to 'false' for actual dismissals
CODEOWNERS_FILE	-	CODEOWNERS	Path to CODEOWNERS file
TARGET_BRANCH	-	main	Target branch to read CODEOWNERS from
CHANGED_FILES	-	-	Newline-separated files (webhook optimization)

🧪 Testing

The project includes comprehensive tests for the pagination implementation:

Quick Test (No API calls needed):

./tests/run-tests.sh

Test with Real Data:

export GITHUB_TOKEN='your_token'
export GITHUB_REPOSITORY='owner/repo'
export PR_NUMBER='123'
export DRY_RUN='true'
./tests/test-real-pagination.sh

Test Files:

• tests/test-pagination.js - Logic tests with simulated data
• tests/test-mock-pagination.js - Mock API tests
• tests/test-real-pagination.sh - Real GitHub API tests
• tests/TESTING.md - Comprehensive testing guide

For detailed testing instructions, see tests/README.md.

💁🏻 Contributing

This is an open source project. Any contribution would be greatly appreciated!

🚩 Issues

If you have found an issue, please report it on the issue tracker