require eslint for PRs

.github/workflows/lint-app.yml

@@ -0,0 +1,34 @@
+name: Lint App
+
+on: workflow_call
+
+jobs:
+  eslint:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+
+      - name: Set up Node.js
+        uses: actions/setup-node@v4
+        with:
+          node-version: "16"
+
+      - name: Cache Node Modules
+        id: node-cache
+        uses: actions/cache@v3
+        with:
+          path: |
+            app/node_modules
+            app/.yarn/cache
+          key: node-modules-${{ hashFiles('app/yarn.lock') }}
+
+      - name: Install Dependencies
+        if: steps.node-cache.outputs.cache-hit != 'true'
+        run: cd app && yarn install
+
+      - name: Read ESLint Packages List and Lint
+        run: |
+          cd app
+          ESLINT_PACKAGES=$(grep -v '^#' ./eslint-packages.txt | xargs)
+          yarn eslint $ESLINT_PACKAGES --max-warnings=0

.github/workflows/pr.yml

@@ -10,6 +10,19 @@ on:
       - release/v[0-9]+.[0-9]+.[0-9]+
 
 jobs:
+  lint:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: dorny/paths-filter@v3
+        id: changes
+        with:
+          filters: |
+            changes:
+              - 'app/**'
+      - if: steps.changes.outputs.changes == 'true'
+        uses: ./.github/workflows/lint-app.yml
+
   build:
     uses: ./.github/workflows/build.yml
 

app/eslint-packages.txt

@@ -0,0 +1,3 @@
+# require these paths to pass linting
+# for PRs to be merge-able
+packages/operators