.github: add code coverage (#689)

* init

* add codecov.yml

.github/workflows/main.yml

@@ -251,3 +251,33 @@ jobs:
         with:
           name: build
           path: target/deploy/drift.so
+  code-coverage:
+    name: Code Coverage
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - name: Install Rust toolchain
+        uses: actions-rs/toolchain@v1
+        with:
+          toolchain: ${{ env.RUST_TOOLCHAIN }}
+          profile: minimal
+          override: true
+      - name: Cache build artefacts
+        uses: Swatinem/rust-cache@v1
+      - name: Run package checks
+        run: cargo check # run package checks
+      - name: Run cargo-tarpaulin
+        uses: actions-rs/[email protected]
+        with:
+          version: '0.15.0'
+          args: '-- --test-threads 1'
+      - name: Upload to codecov.io
+        uses: codecov/[email protected]
+        with:
+          token: ${{secrets.CODECOV_TOKEN}}
+      - name: Archive code coverage results
+        uses: actions/upload-artifact@v1
+        with:
+          name: code-coverage-report
+          path: cobertura.xml
+

codecov.yml

@@ -0,0 +1,9 @@
+comment:
+  layout: "header, diff, flags, components"
+
+component_management:
+  individual_components:
+    - component_id: drift
+      name: drift
+      paths:
+        - programs/drift