chore: Show coverage badge

Author: Oliver Wieland (HC/XAG1)

.github/workflows/badge.yml

@@ -21,22 +21,50 @@ jobs:
     - name: Setup dependencies
       run: |
         sudo apt-get update
-        sudo apt-get install -y ninja-build libspdlog-dev gcc-11 g++-11
+        sudo apt-get install -y ninja-build libspdlog-dev gcc-11 g++-11 lcov python3-pip
+        python3 -m pip install --user anybadge
 
     - name: Set up CMake
       uses: jwlawson/actions-setup-cmake@v1.14
       with:
         cmake-version: 3.20.0
 
-    - name: Quick build test
+    - name: Quick build test (with coverage)
       run: |
-        cmake -B build -G Ninja -DCMAKE_C_COMPILER=gcc-11 -DCMAKE_CXX_COMPILER=g++-11 -DCMAKE_BUILD_TYPE=Release -DWITH_UNIT_TEST=ON
+        cmake -B build -G Ninja \
+          -DCMAKE_C_COMPILER=gcc-11 \
+          -DCMAKE_CXX_COMPILER=g++-11 \
+          -DCMAKE_BUILD_TYPE=Debug \
+          -DWITH_UNIT_TEST=ON \
+          -DCMAKE_CXX_FLAGS="--coverage" \
+          -DCMAKE_C_FLAGS="--coverage"
         cmake --build build --parallel 4
 
     - name: Quick test run
       working-directory: build
       run: ctest --output-on-failure
 
+    - name: Generate coverage report
+      run: |
+        lcov --capture --directory build --output-file coverage.badge.info
+        lcov --remove coverage.badge.info '/usr/*' '*/test/*' '*/build/*' --output-file coverage.badge.info
+        echo "Coverage summary:" && lcov --summary coverage.badge.info
+        PCT=$(lcov --summary coverage.badge.info | awk '/lines/ {gsub("%","", $2); print $2}')
+        echo "CODE_COVERAGE=$PCT" >> $GITHUB_ENV
+
+    - name: Generate coverage badge
+      env:
+        PATH: ${{ env.HOME }}/.local/bin:${{ env.PATH }}
+      run: |
+        anybadge --value=${CODE_COVERAGE} --file=coverage.svg --label="coverage" --suffix="%" \
+          0=red 50=orange 70=yellow 80=yellowgreen 90=green
+
+    - name: Upload coverage badge artifact
+      uses: actions/upload-artifact@v4
+      with:
+        name: coverage-badge
+        path: coverage.svg
+
     - name: Generate badge data
       run: |
         echo "BUILD_STATUS=passing" >> $GITHUB_ENV