Conventions & best practices update

.github/workflows/js.yml

@@ -6,9 +6,33 @@ env:
   NODE_VERSION: 16
 
 jobs:
+  prettier:
+    name: Prettier
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Check out code
+        uses: actions/checkout@v2
+
+      - name: Set up Node
+        uses: actions/setup-node@v2
+        with:
+          node-version: ${{ env.NODE_VERSION }}
+          cache: 'yarn'
+          cache-dependency-path: js/yarn.lock
+
+      - name: Install JS dependencies
+        run: yarn install --immutable
+        working-directory: ./js
+
+      - name: Check JS formatting
+        run: yarn run format-check
+        working-directory: ./js
+
   build-prod:
     name: Build and commit
     runs-on: ubuntu-latest
+    needs: [prettier]
 
     # Only commit JS on push to master branch
     # Remember to change in `build-test` job too
@@ -38,6 +62,7 @@ jobs:
   build-test:
     name: Test build
     runs-on: ubuntu-latest
+    needs: [prettier]
 
     # Inverse check of `build-prod`
     # Remember to change in `build-prod` job too