This example shows how to enforce size limits on pull requests and provide helpful feedback to contributors, encouraging smaller, more focused changes.

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Configuration

ruleset:
  # Rule 2: PR Size Limits
  - name: "PR Size Check"
    when:
      - "pull_request.opened"
      - "pull_request.synchronize"
    validate:
      - type: "size"
        files: 10
        total: 500
        addition: 400
        deletion: 200
        message: "This PR is too large. Please split it into smaller PRs."
    on_failure:
      - label:
          add: ["large-pr"]
      - comment:
          body: |
            ## Large Pull Request Detected

            This PR exceeds our size guidelines:

            {{ validation_summary }}

            Large PRs are harder to review and more likely to introduce bugs. Please consider:

            - Breaking this change into multiple smaller PRs
            - Focusing each PR on a single concern
            - Removing unnecessary changes or generated files

            If this large PR is absolutely necessary, please provide a detailed explanation.

​
How It Works

This ruleset:

  1. Triggers when a PR is opened or synchronized (new commits pushed)
  2. Validates that the PR doesn’t exceed size limits:
    • Maximum 10 files changed
    • Maximum 500 total lines changed
    • Maximum 400 lines added
    • Maximum 200 lines deleted
  3. When the PR is too large:
    • Adds a “large-pr” label
    • Comments with guidance on how to address the issue

​
Extending the Example

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Ignore Certain Files

Exclude files that often change in bulk but don’t require careful review:

validate:
  - type: "size"
    files: 10
    total: 500
    ignore:
      - "package-lock.json"
      - "yarn.lock"
      - "*.generated.ts"
      - "*.min.js"
    message: "This PR is too large (excluding dependency lock files and generated code)."

​
Size-Based Labeling

Automatically label PRs based on their size:

ruleset:
  - name: "Remove Size Labels"
    when:
      - "pull_request.opened"
      - "pull_request.synchronize"
    on_success:
      - label:
          remove:
            ["size: small", "size: medium", "size: large", "size: x-large"]

  - name: "Small PR"
    when:
      - "pull_request.opened"
      - "pull_request.synchronize"
    if:
      - type: "size"
        files:
          max: 3
        total:
          max: 100
    on_success:
      - label:
          add: ["size: small"]

  - name: "Medium PR"
    when:
      - "pull_request.opened"
      - "pull_request.synchronize"
    if:
      - type: "size"
        files:
          min: 4
          max: 10
        total:
          min: 101
          max: 300
    on_success:
      - label:
          add: ["size: medium"]

  - name: "Large PR"
    when:
      - "pull_request.opened"
      - "pull_request.synchronize"
    if:
      - type: "size"
        files:
          min: 11
          max: 20
        total:
          min: 301
          max: 500
    on_success:
      - label:
          add: ["size: large"]

  - name: "X-Large PR"
    when:
      - "pull_request.opened"
      - "pull_request.synchronize"
    if:
      - type: "size"
        files:
          min: 21
        total:
          min: 501
    on_success:
      - label:
          add: ["size: x-large"]
      - comment:
          body: |
            ## Extra Large Pull Request

            This PR is very large and may take longer to review.
            Consider breaking it into smaller, more focused PRs if possible.

​
Different Limits by Branch

Set stricter limits for important branches:

ruleset:
  - name: "Main Branch Size Limits"
    when:
      - "pull_request.opened"
      - "pull_request.synchronize"
    if:
      - type: "branch"
        base:
          match: "main"
    validate:
      - type: "size"
        files: 5
        total: 200
    on_failure:
      - label:
          add: ["large-pr", "needs-split"]
      - comment:
          body: |
            ## PR Too Large for Main Branch

            PRs targeting the main branch must be small and focused.
            Please split this PR into smaller changes.

            {{ validation_summary }}

  - name: "Development Branch Size Limits"
    when:
      - "pull_request.opened"
      - "pull_request.synchronize"
    if:
      - type: "branch"
        base:
          match: "develop"
    validate:
      - type: "size"
        files: 15
        total: 800
    on_failure:
      - label:
          add: ["large-pr"]
      - comment:
          body: |
            ## Large PR

            This PR exceeds our recommended size limits.

            {{ validation_summary }}

​
Strategies for Managing Large PRs

Include helpful advice in your feedback:

on_failure:
  - comment:
      body: |
        ## Large Pull Request Detected

        This PR exceeds our size guidelines. Here are some strategies to make it more manageable:

        1. **Split by feature**: Create separate PRs for each logical feature or change
        2. **Split by layer**: Separate backend/frontend/UI changes into different PRs
        3. **Split by directory**: Create PRs based on directories or components
        4. **Split by steps**: Submit refactoring before adding new features

        Remember that smaller PRs:
        - Get reviewed faster
        - Are more likely to be approved
        - Have fewer bugs
        - Provide quicker feedback

        If splitting isn't possible, please explain why in the PR description.

​
Implementation Tips

  1. Start with generous limits: Begin with larger limits and gradually reduce them
  2. Educate your team: Explain the benefits of smaller PRs
  3. Lead by example: Have maintainers model good PR practices
  4. Make exceptions when needed: Some valid changes (like major refactoring) might need to be larger
  5. Set up your workflow: Use branch protection rules alongside Rulesets

​
Benefits

  • Higher quality code: Smaller PRs get more thorough reviews
  • Faster cycle time: PRs move through the review process more quickly
  • Better collaboration: Reviewers are more willing to review smaller changes
  • Lower cognitive load: Reviewers can focus on one concern at a time
  • Smoother integration: Smaller changes integrate more easily with the codebase