Add code coverage reporting

Assisted-by: Cursor

Author: twaugh

.github/workflows/ci.yml

@@ -25,22 +25,64 @@ jobs:
           diffutils \
           xmlto \
           libpcre2-dev \
-          gnulib
+          gnulib \
+          lcov
 
     - name: Bootstrap
       run: ./bootstrap
 
     - name: Configure
       run: |
         ./configure \
-          --with-pcre2
+          --with-pcre2 \
+          CFLAGS="--coverage -g -O0" \
+          LDFLAGS="--coverage"
 
     - name: Build
       run: make -j$(nproc)
 
     - name: Run tests
       run: make check
 
+    - name: Generate coverage report
+      run: |
+        # Create coverage directory
+        mkdir -p coverage
+
+        # Capture coverage data with geninfo options to handle warnings
+        lcov --capture --directory . --output-file coverage/coverage.info --rc geninfo_unexecuted_blocks=1
+
+        # Remove coverage data for system headers, lib files, and test files
+        lcov --remove coverage/coverage.info '/usr/*' '*/lib/*' '*/tests/*' --output-file coverage/coverage_filtered.info --ignore-errors unused
+
+        # Generate HTML report
+        genhtml coverage/coverage_filtered.info --output-directory coverage/html
+
+        # Generate summary for CI and extract coverage percentage
+        lcov --summary coverage/coverage_filtered.info > coverage/summary.txt
+
+        # Extract coverage percentage for badge
+        COVERAGE=$(grep -o 'lines......: [0-9.]*%' coverage/summary.txt | grep -o '[0-9.]*')
+        echo "COVERAGE_PERCENT=$COVERAGE" >> $GITHUB_ENV
+        echo "Coverage: $COVERAGE%"
+
+    - name: Create coverage badge
+      if: github.ref == 'refs/heads/master' && github.event_name == 'push' && secrets.GIST_ID != ''
+      uses: schneegans/dynamic-badges-action@v1.7.0
+      with:
+        auth: ${{ secrets.GITHUB_TOKEN }}
+        gistID: ${{ secrets.GIST_ID }}
+        filename: patchutils-coverage.json
+        label: coverage
+        message: ${{ env.COVERAGE_PERCENT }}%
+        color: ${{ env.COVERAGE_PERCENT > 80 && 'brightgreen' || env.COVERAGE_PERCENT > 60 && 'yellow' || 'red' }}
+
+    - name: Upload coverage reports
+      uses: actions/upload-artifact@v4
+      with:
+        name: coverage-report
+        path: coverage/
+
     - name: Show test results on failure
       if: failure()
       run: |

README.md

@@ -1,5 +1,8 @@
 # Patchutils
 
+[![CI](https://github.com/twaugh/patchutils/actions/workflows/ci.yml/badge.svg)](https://github.com/twaugh/patchutils/actions/workflows/ci.yml)
+[![Coverage](https://img.shields.io/endpoint?url=https://gist.githubusercontent.com/twaugh/bb6c2090db1f9d5af4689a0d9affdc02/raw/patchutils-coverage.json)](https://github.com/twaugh/patchutils/actions/workflows/ci.yml)
+
 A collection of tools that operate on patch files.
 
 ## Overview