ci: generate coverage report

.github/workflows/ci.yml

@@ -119,3 +119,23 @@ jobs:
 
       - name: Run integration tests
         run: cargo test --profile tests-integration --workspace --exclude tlsn-tls-client --exclude tlsn-tls-core -- --include-ignored
+  coverage:
+    runs-on: ubuntu-latest
+    env:
+      CARGO_TERM_COLOR: always
+    steps:
+      - uses: actions/checkout@v4
+      - name: Install stable rust toolchain
+        uses: dtolnay/rust-toolchain@stable
+        with:
+          toolchain: 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 --exclude tlsn-tls-client --exclude tlsn-tls-core --html
+      - name: Save coverage report
+        uses: actions/upload-artifact@v4
+        with:
+          name: coverage-report
+          path: ./target/llvm-cov/html/
+          if-no-files-found: error