Discord Github PR Notification

[Yash-Rawat-IIT-D]

Add Discord Notifications for PR Merges

Summary

This PR introduces a GitHub Actions workflow and a lightweight Python script to send notifications to Discord when pull requests are merged.

Motivation

The repository contains multiple target branches (p1-*, p2-*, …), and PRs may target any of them. Maintaining separate workflows across all branches would be difficult and error-prone.
This change centralizes automation in a single place and provides visibility into merge activity via Discord.

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Key Design Choices

1. Use of pull_request_target

• The workflow is triggered using:

  pull_request_target:
    types: [closed]

• This ensures:

  • The workflow is always loaded from the default branch (main)
  • No need to duplicate .github/workflows across all pX-* branches

2. Filter only merged PRs

• The closed event includes both merged and non-merged PRs

• Filtering is handled in scripts/notify.py:

  • Only merged PRs generate notifications

3. Python-based notification logic

• All formatting and routing logic is implemented in scripts/notify.py
• This avoids complex YAML scripting and makes future extensions easier

4. Discord Webhook Integration

• Uses repository secret:

  DISCORD_WEBHOOK
  

• Sends structured messages (embed format) to the configured Discord channel (#pr-merges)

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Features (Initial Scope)

• Notify when a PR is merged

• Include:

  • PR title
  • PR number
  • Author
  • Target branch
  • Direct link to PR

• Clean embed-based formatting for readability

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Files Added

.github/workflows/discord.yml   # Workflow definition
scripts/notify.py              # Notification logic

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Testing

• Tested via push events on a personal repository

• Verified:

  • Webhook delivery
  • Embed formatting
  • Environment variable handling

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Future Improvements

• Notifications for:

  • PR comments
  • PR reviews

• Label-based routing (e.g., errata vs development)

• Multiple Discord channels

• Improved formatting (icons, richer embeds)

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Notes

• No existing functionality is modified
• Safe usage of pull_request_target (no execution of untrusted PR code)
• Minimal, incremental rollout for easier review

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Expected Outcome

Once merged, all future PR merges (to any pX-* branch) will automatically trigger a Discord notification without requiring additional configuration.