Add codecov.io integration

.github/workflows/ci.yml

@@ -14,7 +14,7 @@ jobs:
       fail-fast: false
       matrix:
         os: [windows-latest, macos-latest, ubuntu-latest]
-        rust_version: [1.58.0, stable]
+        rust_version: [stable]
 
     steps:
       - name: Checkout repository
@@ -24,18 +24,56 @@ jobs:
         uses: actions-rs/toolchain@v1
         with:
           toolchain: ${{ matrix.rust_version }}
+          components: llvm-tools-preview
           override: true
 
       - name: Cache Rust dependencies
         uses: Swatinem/rust-cache@v1
 
+      - name: Install cargo-llvm-cov
+        uses: taiki-e/install-action@cargo-llvm-cov
+
+      - name: Generate code coverage
+        run: cargo llvm-cov --all-features --workspace --lcov --output-path lcov.info
+
+      - name: Upload code coverage results
+        uses: codecov/codecov-action@v2
+        with:
+          fail_ci_if_error: true
+
+  tests-msrv:
+    name: Unit tests
+    runs-on: ${{ matrix.os }}
+
+    strategy:
+      fail-fast: false
+      matrix:
+        os: [windows-latest, macos-latest, ubuntu-latest]
+        rust_version: [1.58.0]
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v3
+
+      - name: Install Rust toolchain
+        uses: actions-rs/toolchain@v1
+        with:
+          toolchain: ${{ matrix.rust_version }}
+          override: true
+
+      - name: Cache Rust dependencies
+        uses: Swatinem/rust-cache@v1
+
+      # Note that we do not run code coverage because
+      # it was not stabilized as of 1.58.0.
+
       - name: Run self tests
         uses: actions-rs/cargo@v1
         with:
           command: test
           # args: --all-targets --all-features --workspace (waiting on bug fix)
           args: --all-features --workspace
-        
+
   wasm_tests:
     name: Wasm tests
     runs-on: ubuntu-latest