ci: add ExUnit test workflow for pull requests

.forgejo/workflows/pr-tests.yaml

@@ -0,0 +1,85 @@
+name: Pull Request Tests
+
+on:
+  pull_request:
+    branches:
+      - main
+      - production
+
+env:
+  MIX_ENV: test
+
+jobs:
+  test-exunit:
+    name: Run ExUnit Tests
+    runs-on: ubuntu-22.04
+    env:
+      DATABASE_URL: ecto://postgres:postgres@postgres/towerops_test
+
+    services:
+      postgres:
+        image: timescale/timescaledb:latest-pg17
+        env:
+          POSTGRES_USER: postgres
+          POSTGRES_PASSWORD: postgres
+          POSTGRES_DB: towerops_test
+        options: >-
+          --health-cmd pg_isready
+          --health-interval 10s
+          --health-timeout 5s
+          --health-retries 5
+
+    steps:
+      - name: Checkout code
+        uses: https://github.com/actions/checkout@v4
+
+      - name: Set up Elixir
+        uses: https://github.com/erlef/setup-beam@v1
+        with:
+          version-type: strict
+          elixir-version: '1.18.1'
+          otp-version: '27.2'
+
+      - name: Cache Mix
+        uses: https://github.com/actions/cache@v4
+        with:
+          path: ~/.mix
+          key: ${{ runner.os }}-mix-1.18.1-27.2
+          restore-keys: ${{ runner.os }}-mix-
+
+      - name: Cache deps
+        uses: https://github.com/actions/cache@v4
+        with:
+          path: deps
+          key: ${{ runner.os }}-deps-${{ hashFiles('mix.lock') }}
+          restore-keys: ${{ runner.os }}-deps-
+
+      - name: Cache _build
+        uses: https://github.com/actions/cache@v4
+        with:
+          path: _build
+          key: ${{ runner.os }}-build-${{ hashFiles('lib/**/*.ex') }}-${{ hashFiles('mix.lock') }}
+          restore-keys: ${{ runner.os }}-build-
+
+      - name: Install system dependencies
+        run: |
+          sudo apt-get update
+          sudo apt-get install -y libssl-dev libsnmp-dev snmp-mibs-downloader postgresql-client
+
+      - name: Install dependencies
+        run: mix deps.get
+
+      - name: Compile (warnings as errors)
+        run: mix compile --warnings-as-errors
+
+      - name: Run tests
+        run: mix test
+
+      - name: Test summary
+        if: always()
+        run: |
+          if [ ${{ job.status }} == 'success' ]; then
+            echo "### ✅ All tests passed" >> $GITHUB_STEP_SUMMARY
+          else
+            echo "### ❌ Tests failed" >> $GITHUB_STEP_SUMMARY
+          fi