GH-127: Add PR label check

Author: lcombs15

.github/actions/setup-python/action.yml

@@ -0,0 +1,10 @@
+name: "Setup Python"
+description: "Setup the correct version of python"
+
+runs:
+  using: "composite"
+  steps:
+    - name: Set up Python
+      uses: actions/setup-python@v5
+      with:
+        python-version: 3.13

.github/workflows/build.yml

@@ -20,19 +20,13 @@ jobs:
 
     steps:
       - uses: actions/checkout@v5
-      - name: Set up Python
-        uses: actions/setup-python@v5
-        with:
-          python-version: 3.13
+      - uses: ./.github/actions/setup-python
       - name: Install dependencies
         run: |
           python scripts/os_specific_requirements.py
           python -m pip install --upgrade pip
           pip install -r requirements.txt
         shell: bash
-      - name: Prepare Scripts
-        run: |
-          chmod +x scripts/*
       - name: Lint
         run: |
           python scripts/lint.py

.github/workflows/pr-label-check.yml

@@ -0,0 +1,17 @@
+name: PR Label Check
+
+on:
+  pull_request:
+    types: [opened, labeled, unlabeled]
+
+jobs:
+  validate-labels:
+    name: Validate release label
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: ./.github/actions/setup-python
+      - name: Check PR has exactly one release label
+        run: |
+          python scripts/pr_label_check.py "$GITHUB_EVENT_PATH"
+        shell: bash

scripts/pr_label_check.py

@@ -0,0 +1,52 @@
+"""
+    Ensure a pull request has exactly one version label
+"""
+import os
+import sys
+import json
+
+VALID_LABELS = {'Patch', 'Minor', 'Major', "no-release"}
+
+def extract_labels_from_event(event_file: str) -> set[str]:
+    """Extract label names from a GitHub event JSON file.
+
+    Args:
+        event_file: Path to the JSON event file produced by GitHub Actions.
+
+    Returns:
+        A set of label names (strings) found on the pull request.
+    """
+    with open(event_file, 'r', encoding='utf-8') as f:
+        payload = json.load(f)
+    labels = payload.get('pull_request', {}).get('labels', [])
+    return {str(lbl.get('name', '')).strip() for lbl in labels}
+
+
+def are_labels_valid(labels_on_pr: set[str]) -> bool:
+    """Check whether the PR has exactly one allowed version label.
+
+    Args:
+        labels_on_pr: Set of label names present on the pull request.
+
+    Returns:
+        True if exactly one label from VALID_LABELS is present; otherwise False.
+    """
+    print(f"Found labels on pull request: {labels_on_pr}")
+    overlap = VALID_LABELS.intersection(labels_on_pr)
+    return len(overlap) == 1
+
+
+if __name__ == "__main__":
+    print("Checking pull request labels")
+    event_path = sys.argv[1]
+    success: bool = False
+    if event_path and os.path.isfile(event_path):
+        all_labels = extract_labels_from_event(event_path)
+        success = are_labels_valid(all_labels)
+    else:
+        print("No labels found")
+
+    if not success:
+        print(f"Did not find exactly one of the following labels: {VALID_LABELS}")
+
+    sys.exit(0 if success else 1)