feat: add code coverage with branch coverage

- Add --enable-coverage option to configure.ac
- Add coverage/coverage-html targets to Makefile.am
- Add coverage CI job with lcov + Codecov upload
- Include both unit and functional tests in coverage
- Enable branch coverage (step towards MC/DC)
- Add lcov to all Dockerfiles
- Add coverage/ to .gitignore

.github/workflows/ci-code.yml

@@ -98,3 +98,33 @@ jobs:
       - name: Check spelling
         run: |
           codespell
+
+  coverage:
+    runs-on: ubuntu-latest
+    name: Code Coverage
+    steps:
+      - uses: actions/checkout@v4
+      - name: Build and run coverage
+        run: |
+          docker build -f Dockerfile.debian -t profanity-cov .
+          docker run -v ${{ github.workspace }}/coverage:/coverage profanity-cov bash -c '
+            ./bootstrap.sh
+            ./configure --enable-coverage --enable-otr --enable-pgp --enable-omemo --enable-plugins
+            make -j$(nproc)
+            make check || true
+            make check-functional-parallel || true
+            lcov --capture --directory . --output-file /coverage/coverage.info \
+              --rc branch_coverage=1 \
+              --ignore-errors inconsistent
+            lcov --remove /coverage/coverage.info \
+              "/usr/include/*" "*/tests/*" \
+              --output-file /coverage/coverage.info \
+              --rc branch_coverage=1 \
+              --ignore-errors inconsistent,empty,unused
+          '
+      - name: Upload coverage to Codecov
+        uses: codecov/codecov-action@v4
+        with:
+          files: ./coverage/coverage.info
+          fail_ci_if_error: false
+          verbose: true

.gitignore

@@ -107,3 +107,4 @@ breaks
 *.tar.*
 *.zip
 *.log*
+coverage/

Dockerfile.arch

@@ -17,6 +17,7 @@ RUN pacman -S --needed --noconfirm \
   check \
   cmake \
   cmocka \
+  lcov \
   curl \
   debuginfod \
   doxygen \

Dockerfile.debian

@@ -12,6 +12,7 @@ RUN apt-get update && apt-get install -y --no-install-recommends \
   ccache \
   gcc \
   git \
+  lcov \
   libcmocka-dev \
   libcurl3-dev \
   libgcrypt-dev \

Dockerfile.fedora

@@ -14,6 +14,7 @@ RUN dnf install -y \
   ccache \
   gcc \
   git \
+  lcov \
   glib2-devel \
   glibc-all-langpacks \
   gtk2-devel \

Dockerfile.tumbleweed

@@ -13,6 +13,7 @@ RUN zypper --non-interactive in --no-recommends \
   ccache \
   gcc \
   git \
+  lcov \
   glib2-devel \
   glibc-locale \
   gtk2-devel \

Dockerfile.ubuntu

@@ -11,6 +11,7 @@ RUN apt-get update && apt-get install -y --no-install-recommends \
   ccache \
   gcc \
   git \
+  lcov \
   libcmocka-dev \
   libcurl3-dev \
   libgcrypt-dev \

Makefile.am

@@ -386,6 +386,20 @@ check-unit: tests/unittests/unittests
 @VALGRIND_CHECK_RULES@
 VALGRIND_SUPPRESSIONS_FILES=prof.supp
 
+# Code coverage targets (requires --enable-coverage)
+coverage-clean:
+	find . -name '*.gcda' -delete
+	find . -name '*.gcno' -delete
+	rm -rf coverage-html coverage.info
+
+coverage-report: check
+	lcov --capture --directory . --output-file coverage.info --ignore-errors inconsistent
+	lcov --remove coverage.info '/usr/*' '*/tests/*' --output-file coverage.info --ignore-errors inconsistent
+	genhtml coverage.info --output-directory coverage-html
+	@echo "Coverage report generated in coverage-html/index.html"
+
+.PHONY: coverage-clean coverage-report
+
 format: $(all_c_sources)
 	clang-format -i $(all_c_sources)
 

configure.ac

@@ -69,6 +69,8 @@ AC_ARG_ENABLE([gdk-pixbuf],
     [AS_HELP_STRING([--enable-gdk-pixbuf], [enable GDK Pixbuf support to scale avatars before uploading])])
 AC_ARG_ENABLE([omemo-qrcode],
     [AS_HELP_STRING([--enable-omemo-qrcode], [enable ability to display omemo qr code])])
+AC_ARG_ENABLE([coverage],
+    [AS_HELP_STRING([--enable-coverage], [enable code coverage analysis])])
 
 m4_include([m4/ax_valgrind_check.m4])
 AX_VALGRIND_DFLT([drd], [off])
@@ -386,6 +388,11 @@ AC_SUBST([FORKPTY_LIB])
 AM_CFLAGS="$AM_CFLAGS -Wall -Wno-deprecated-declarations -std=gnu99 -ggdb3"
 AM_LDFLAGS="$AM_LDFLAGS -export-dynamic"
 
+AS_IF([test "x$enable_coverage" = xyes],
+    [AM_CFLAGS="$AM_CFLAGS --coverage -O0"
+     AM_LDFLAGS="$AM_LDFLAGS --coverage"
+     AC_MSG_NOTICE([Code coverage analysis enabled])])
+
 AS_IF([test "x$PACKAGE_STATUS" = xdevelopment],
     [AM_CFLAGS="$AM_CFLAGS -Wunused -Werror"])
 AS_IF([test "x$PLATFORM" = xosx],