ci: Automatically label PR from conventional commit

.github/workflows/enforce-label.yml

@@ -1,31 +1,90 @@
 name: Enforce PR label
 
 on:
-  pull_request:
+  pull_request_target:
     types: [labeled, unlabeled, opened, edited, synchronize]
 
+permissions:
+  issues: write
+  pull-requests: write
+
 jobs:
   pr-title:
     name: Check conventional commit PR title
     runs-on: ubuntu-latest
     steps:
       - name: Checkout repository
         uses: actions/checkout@v4
+        with:
+          # WARN: With `pull_request_target` it is unsafe to execute user code, we execute
+          # pixi/commitlint from target branch.
+          ref: ${{ github.event.pull_request.base.sha }}
       - name: Setup Pixi
         uses: prefix-dev/setup-pixi@v0.9.3
         with:
           pixi-version: v0.60.0
           cache: true
           manifest-path: pyproject.toml
       - name: Verify conventional commit conventions on PR title
+        id: commitlint
         run: echo "${{ github.event.pull_request.title }}" | pixi run commitlint
-        # TODO: we have not added the labels but we can add them automatically
-        # from conventional commit titles
-        # pr-label:
-        #   name: Check PR label
-        #   runs-on: ubuntu-latest
-        #   permissions:
-        #     pull-requests: write
-        #   steps:
-        #     - name: enforce-triage-label
-        #       uses: jupyterlab/maintainer-tools/.github/actions/enforce-label@v1
+      - name: Apply PR label
+        if: success()
+        uses: actions/github-script@v8
+        with:
+          github-token: ${{ secrets.GITHUB_TOKEN }}
+          script: |-
+            const title = context.payload.pull_request.title;
+
+            // Extract conventional commit type and optional scope
+            const match = title.match(/^([a-z]+)(?:\(([a-z]+)\))?:/);
+            if (!match) {
+              console.log("No conventional commit type found in PR title");
+              return;
+            }
+
+            const commitType = match[1];
+            const commitScope = match[2]; // optional
+            console.log(`Detected commit type: ${commitType}`);
+            if (commitScope) {
+              console.log(`Detected commit scope: ${commitScope}`);
+            }
+
+            // Map commit types to PR labels
+            const typeToLabel = {
+              "fix": "bug",
+              "feat": "feature",
+              "doc": "documentation",
+              "chore": "maintenance",
+              "ci": "maintenance",
+              "dev": "maintenance",
+              "test": "maintenance",
+              "perf": "enhancement",
+              "release": "maintenance",
+              "revert": "maintenance"
+            };
+
+            const label = typeToLabel[commitType];
+            if (!label) {
+              console.log(`No label mapping found for commit type: ${commitType}`);
+              return;
+            }
+
+            console.log(`Applying type label: ${label}`);
+
+            // Collect labels to add
+            const labelsToAdd = [label];
+
+            // Add scope label if applicable (client or server)
+            if (commitScope && ["client", "server"].includes(commitScope)) {
+              console.log(`Applying scope label: ${commitScope}`);
+              labelsToAdd.push(commitScope);
+            }
+
+            // Apply labels (GitHub API is idempotent - ignores already present labels)
+            await github.rest.issues.addLabels({
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+              issue_number: context.payload.pull_request.number,
+              labels: labelsToAdd
+            });