check-pr-title.yml

name: Check-PR-Title

on:
  pull_request:
    types:
      - opened
      - edited
      - synchronize
      - reopened

jobs:
  title-check:
    runs-on: ubuntu-latest
    steps:
      - name: Enforce imperative subject (heuristic)
        uses: actions/github-script@v7
        with:
          script: |
            const title = context.payload.pull_request.title;

            // -----------------------------
            // 1) Imperative heuristic
            // -----------------------------
            const bannedStarts = new Set([
              "Added", "Adding", "Adds",
              "Fixed", "Fixes", "Fixing",
              "Updated", "Updating", "Updates",
              "Changed", "Changing", "Changes",
              "Removed", "Removing", "Removes",
              "Refactored", "Refactoring",
              "Improved", "Improving",
              "Implemented", "Implementing", "Implements",
              "Created", "Creating", "Creates",
              "Renamed", "Renaming", "Renames",
              "Moved", "Moving", "Moves",
              "Deleted", "Deleting", "Deletes",
              "Reverted", "Reverting", "Reverts",
              "Bumped", "Bumping", "Bumps",
              "Upgraded", "Upgrading", "Upgrades",
              "Downgraded", "Downgrading", "Downgrades",
              "Pinned", "Pinning", "Pins",
              "Resolved", "Resolving", "Resolves",
              "Corrected", "Correcting", "Corrects",
              "Addressed", "Addressing", "Addresses",
              "Patched", "Patching", "Patches",
              "Cleaned", "Cleaning", "Cleans",
              "Formatted", "Formatting", "Formats",
              "Linted", "Linting", "Lints",
              "Sorted", "Sorting", "Sorts",
              "Documented", "Documenting", "Documents",
              "Tested", "Testing", "Tests",
              "Optimized", "Optimizing", "Optimizes",
              "Enhanced", "Enhancing", "Enhances",
              "Simplified", "Simplifying", "Simplifies",
              "Adjusted", "Adjusting", "Adjusts",
              "Modified", "Modifying", "Modifies",
            ]);

            const firstWord = title.split(/\s+/)[0];
            if (bannedStarts.has(firstWord)) {
              core.setFailed(
                `PR title subject should be present imperative. ` +
                `Avoid "${firstWord} …". Example: "Add …", "Fix …", "Update …".`
              );
            }

            // -----------------------------
            // 2) Allow leading emojis, but:
            //    - Reject WIP prefixes
            //    - Require first "real" word to start uppercase
            // -----------------------------
            const trimmed = title.trim();

            // Reject WIP at the start (optionally wrapped in [] or () and optionally followed by ":" or "-")
            if (/^\s*[\[(]?\s*wip\s*[\])]?(\s*[:\-–—])?/i.test(trimmed)) {
              core.setFailed(`PR title must not be WIP.`);
            }

            // Find the first letter-starting word, allowing leading non-letters (e.g., emojis, punctuation)
            const match = trimmed.match(/[A-Za-z][A-Za-z0-9'’]*/);

            if (!match) {
              core.setFailed(`PR title must contain a word.`);
            } else {
              const firstRealWord = match[0];
              const firstChar = firstRealWord[0];

              if (firstChar !== firstChar.toUpperCase()) {
                const suggested =
                  trimmed.replace(
                    firstRealWord,
                    firstChar.toUpperCase() + firstRealWord.slice(1)
                  );

                core.setFailed(
                  `PR title must start with a capitalized word (emojis are fine). ` +
                  `Example: "${suggested}"`
                );
              }
            }