ci: add coverage workflow (#2)

* ci: add coverage workflow

* rename job to coverage

* add codecov token

.github/workflows/coverage.yaml

@@ -0,0 +1,45 @@
+name: Coverage
+
+on:
+  push:
+    branches: ["main"]
+  pull_request:
+    branches: ["main"]
+
+env:
+  CARGO_TERM_COLOR: always
+
+jobs:
+  coverage:
+    runs-on: ubuntu-latest
+
+    env:
+      DATABASE_URL: "postgres://postgres:postgres@localhost:5432/postgres"
+
+    services:
+      postgres:
+        image: postgres:16
+        env:
+          POSTGRES_PASSWORD: postgres
+        options: >-
+          --health-cmd pg_isready
+          --health-interval 10s
+          --health-timeout 5s
+          --health-retries 5
+        ports:
+          - 5432:5432
+
+    steps:
+      - uses: actions/checkout@v4
+      - name: Install Rust
+        run: rustup update stable
+      - name: Install cargo-llvm-cov
+        uses: taiki-e/install-action@cargo-llvm-cov
+      - name: Generate code coverage
+        run: cargo llvm-cov --all-features --workspace --codecov --output-path codecov.json
+      - name: Upload coverage to Codecov
+        uses: codecov/codecov-action@v3
+        with:
+          token: ${{ secrets.CODECOV_TOKEN }}
+          files: codecov.json
+          fail_ci_if_error: true