CI: Add formatting check

Author: parisk

.github/workflows/ci.yml

@@ -3,7 +3,8 @@ name: CI
 on: push
 
 jobs:
-  deploy:
+  test-python:
+    name: Test (Python)
     runs-on: ubuntu-latest
     steps:
     - uses: actions/checkout@v3
@@ -14,3 +15,15 @@ jobs:
         cache: poetry
     - run: poetry install
     - run: poetry run black --check .
+
+  test-js:
+    name: Test (JavaScript)
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v3
+    - uses: actions/setup-node@v3
+      with:
+        node-version: '20.x'
+        cache: yarn
+    - run: yarn
+    - run: yarn lint

package.json

@@ -11,6 +11,8 @@
     "prettier": "3.0.2"
   },
   "scripts": {
-    "format": "yarn prettier prose/static/prose --write"
+    "prettier:base": "yarn prettier prose/static/prose",
+    "lint": "yarn prettier:base --check",
+    "format": "yarn prettier:base --write"
   }
 }