feat: implement /assign GitHub Action

.github/workflows/assign.yml

@@ -0,0 +1,131 @@
+name: Issue / PR Self-Assign
+
+on:
+  issue_comment:
+    types: [created]
+
+permissions:
+  issues: write
+  pull-requests: write
+
+jobs:
+  assign:
+    if: |
+      !github.event.sender.type == 'Bot' &&
+      contains(github.event.comment.body, '/assign')
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Parse /assign command
+        id: parse
+        uses: actions/github-script@v7
+        with:
+          script: |
+            const body       = context.payload.comment.body.trim();
+            const commenter  = context.payload.comment.user.login;
+            const senderType = context.payload.comment.user.type;
+
+            if (senderType === 'Bot') {
+              core.setOutput('skip', 'true');
+              return;
+            }
+
+            // Supports /assign or /assign @username
+            const match = body.match(/^\/assign(?:\s+@?([\w-]+))?/im);
+
+            if (!match) {
+              core.setOutput('skip', 'true');
+              return;
+            }
+
+            const targetUser = match[1] ? match[1] : commenter;
+
+            core.setOutput('skip',        'false');
+            core.setOutput('target_user', targetUser);
+            core.setOutput('commenter',   commenter);
+
+      - name: Assign user
+        if: steps.parse.outputs.skip == 'false'
+        uses: actions/github-script@v7
+        with:
+          github-token: ${{ secrets.GITHUB_TOKEN }}
+          script: |
+            const targetUser  = '${{ steps.parse.outputs.target_user }}';
+            const commenter   = '${{ steps.parse.outputs.commenter }}';
+            const issueNumber = context.payload.issue.number;
+            const owner       = context.repo.owner;
+            const repo        = context.repo.repo;
+
+            async function postComment(body) {
+              await github.rest.issues.createComment({
+                owner, repo, issue_number: issueNumber, body
+              });
+            }
+
+            let userMeta;
+            try {
+              const { data } = await github.rest.users.getByUsername({ username: targetUser });
+              userMeta = data;
+            } catch (err) {
+              if (err.status === 404) {
+                await postComment(
+                  `> ❌ @${commenter} – \`${targetUser}\` is not a valid GitHub username. ` +
+                  `Please check the spelling and try again.`
+                );
+                core.setFailed(`User '${targetUser}' not found on GitHub.`);
+                return;
+              }
+              throw err;
+            }
+
+            if (userMeta.type === 'Bot') {
+              await postComment(
+                `> ⚠️ @${commenter} – bot accounts cannot be assigned to issues or PRs.`
+              );
+              return;
+            }
+
+            const { data: issue } = await github.rest.issues.get({
+              owner, repo, issue_number: issueNumber
+            });
+
+            const currentAssignees = issue.assignees.map(a => a.login.toLowerCase());
+
+            if (currentAssignees.includes(targetUser.toLowerCase())) {
+              const isSelf = targetUser.toLowerCase() === commenter.toLowerCase();
+              await postComment(
+                isSelf
+                  ? `> ℹ️ @${commenter} – you are already assigned to this ${issue.pull_request ? 'PR' : 'issue'}.`
+                  : `> ℹ️ @${commenter} – \`${targetUser}\` is already assigned to this ${issue.pull_request ? 'PR' : 'issue'}.`
+              );
+              return;
+            }
+
+            try {
+              await github.rest.issues.addAssignees({
+                owner,
+                repo,
+                issue_number: issueNumber,
+                assignees: [targetUser]
+              });
+            } catch (err) {
+              // GitHub returns 422 when a user lacks repo access
+              if (err.status === 422) {
+                await postComment(
+                  `> ❌ @${commenter} – \`${targetUser}\` could not be assigned. ` +
+                  `They may not have the necessary repository access. ` +
+                  `Please ask a maintainer for help.`
+                );
+                core.setFailed(`Cannot assign '${targetUser}' – insufficient permissions.`);
+                return;
+              }
+              throw err;
+            }
+
+            const isSelf   = targetUser.toLowerCase() === commenter.toLowerCase();
+            const itemType = issue.pull_request ? 'PR' : 'issue';
+            await postComment(
+              isSelf
+                ? `> ✅ @${commenter} has self-assigned this ${itemType}. Good luck! 🚀`
+                : `> ✅ @${commenter} has assigned @${targetUser} to this ${itemType}.`
+            );

CONTRIBUTING.md

@@ -82,20 +82,46 @@ devcard/
 - **Conventional Commits** for commit messages (`feat:`, `fix:`, `docs:`, `chore:`)
 - Write tests for new features and bug fixes
 
+## Self-Assigning Issues & PRs
+
+You can assign yourself (or another contributor) to any open issue or pull request by posting a comment with the `/assign` command — no maintainer action required.
+
+| Command | Effect |
+|---|---|
+| `/assign` | Assigns **you** (the commenter) to the issue/PR |
+| `/assign @username` | Assigns the specified GitHub **@username** |
+
+**Examples:**
+
+```
+/assign
+```
+```
+/assign @octocat
+```
+
+The bot will reply with a confirmation comment (or an error message if the username is invalid, the user is already assigned, or the account lacks repo access).
+
+> **Note:** Bot accounts cannot be assigned. Duplicate assignments are silently prevented.
+
+---
+
 ## Pull Request Process
 
 1. Create a feature branch from `main`: `git checkout -b feat/your-feature`
-2. Make your changes with clear, descriptive commits
-3. Ensure all tests pass: `pnpm test`
-4. Ensure linting passes: `pnpm lint`
-5. Open a PR against `main` with a clear description of the change
-6. Wait for review — maintainers will respond within 48 hours
+2. Self-assign the related issue with `/assign` so others know you're working on it
+3. Make your changes with clear, descriptive commits
+4. Ensure all tests pass: `pnpm test`
+5. Ensure linting passes: `pnpm lint`
+6. Open a PR against `main` with a clear description of the change
+7. Wait for review — maintainers will respond within 48 hours
 
 ## Reporting Issues
 
 - Use GitHub Issues for bug reports and feature requests
 - Include reproduction steps for bugs
 - Search existing issues before creating a new one
+- Use `/assign` on an issue you plan to fix so work isn't duplicated
 
 ## Code of Conduct
 

VERIFY_IMPLEMENTATION.txt

@@ -0,0 +1,62 @@
+# Implementation Verification & Setup Guide
+
+This guide covers how to set up the project and verify the newly implemented `/assign` GitHub Action.
+
+## 1. Local Project Setup
+To ensure your local environment matches the project structure and all dependencies are present:
+
+1. **Install pnpm** (if not already installed):
+   ```bash
+   npm install -g pnpm
+   ```
+
+2. **Install Dependencies**:
+   Run this from the root of the repository to install all workspace dependencies:
+   ```bash
+   pnpm install
+   ```
+
+3. **Verify Configuration Files**:
+   - Check that `.github/workflows/assign.yml` exists.
+   - Check that `CONTRIBUTING.md` includes the "Self-Assigning Issues & PRs" section.
+
+---
+
+## 2. Verifying the GitHub Action
+GitHub Actions run on GitHub's infrastructure. To verify the `/assign` command:
+
+1. **Push Changes**:
+   Ensure the new `.github/workflows/assign.yml` file is pushed to your GitHub repository.
+   ```bash
+   git add .github/workflows/assign.yml CONTRIBUTING.md
+   git commit -m "feat: implement /assign GitHub Action"
+   git push origin <your-branch-name>
+   ```
+
+2. **Trigger the Action**:
+   - Open any Issue or Pull Request on your GitHub repository.
+   - Post a comment: `/assign`
+   - **Expected Result**: The "Issue / PR Self-Assign" workflow should trigger. You can see this under the "Actions" tab.
+   - **Confirmation**: A bot (github-actions) should reply to your comment and you should be added as an assignee.
+
+3. **Test Edge Cases**:
+   - Post: `/assign @nonexistent_user_12345` (Should reply with an error).
+   - Post: `/assign @another_valid_user` (Should assign that user).
+   - Post: `/assign` again (Should notify you that you are already assigned).
+
+---
+
+## 3. Optional: Local Workflow Testing
+If you want to test the workflow logic without pushing to GitHub, you can use **act**:
+
+1. **Install act**:
+   ```bash
+   brew install nektos/tap/act
+   ```
+
+2. **Run the workflow**:
+   Note: This requires Docker to be running.
+   ```bash
+   act issue_comment
+   ```
+   *(Note: You may need to provide a mock event JSON to simulate a specific comment body like "/assign")*