refactor: enhance CI workflow with C++ linting and coverage checks

.clang-format

@@ -0,0 +1,10 @@
+---
+BasedOnStyle: LLVM
+IndentWidth: 4
+ContinuationIndentWidth: 4
+ColumnLimit: 0
+PointerAlignment: Left
+ReferenceAlignment: Left
+AlignConsecutiveAssignments: Consecutive
+AlignConsecutiveDeclarations: Consecutive
+...

.github/workflows/ci.yml

@@ -10,8 +10,69 @@ concurrency:
 
 permissions:
   contents: read
+  checks: write
+  pull-requests: write
 
 jobs:
+  lint-cpp:
+    name: C++ Lint (clang-format + clang-tidy)
+    runs-on: ubuntu-22.04
+    env:
+      CARGO_TERM_COLOR: always
+    steps:
+      - name: Checkout (with submodules)
+        uses: actions/checkout@v4
+        with:
+          submodules: recursive
+          fetch-depth: 0
+
+      - name: Install system dependencies
+        shell: bash
+        run: |
+          set -euo pipefail
+          sudo apt-get update
+          sudo apt-get install -y --no-install-recommends \
+            cmake \
+            ninja-build \
+            clang-format \
+            clang-tidy
+
+      - name: Set up Rust (stable)
+        uses: actions-rust-lang/setup-rust-toolchain@v1
+        with:
+          toolchain: stable
+
+      - name: Configure (CMake, compile commands)
+        shell: bash
+        run: |
+          set -euo pipefail
+          cmake -S . -B build -G Ninja -DSIDERUST_BUILD_DOCS=OFF -DCMAKE_EXPORT_COMPILE_COMMANDS=ON
+
+      - name: clang-format check
+        shell: bash
+        run: |
+          set -euo pipefail
+          mapfile -t files < <(git ls-files '*.hpp' '*.cpp')
+          if [ ${#files[@]} -eq 0 ]; then
+            echo "No C++ files found."
+            exit 0
+          fi
+          clang-format --dry-run --Werror "${files[@]}"
+
+      - name: clang-tidy check
+        shell: bash
+        run: |
+          set -euo pipefail
+          mapfile -t cpp_files < <(git ls-files '*.cpp')
+          if [ ${#cpp_files[@]} -eq 0 ]; then
+            echo "No C++ source files found."
+            exit 0
+          fi
+          for file in "${cpp_files[@]}"; do
+            echo "Running clang-tidy on ${file}"
+            clang-tidy -p build --warnings-as-errors='*' "${file}"
+          done
+
   build-test-docs:
     name: Build + Test + Docs
     runs-on: ubuntu-22.04
@@ -90,3 +151,114 @@ jobs:
         run: |
           set -euo pipefail
           cmake --build build --target docs
+
+  coverage:
+    name: Test & Coverage
+    if: ${{ github.event_name != 'pull_request' || github.event.pull_request.draft == false }}
+    runs-on: ubuntu-22.04
+    env:
+      CARGO_TERM_COLOR: always
+    steps:
+      - name: Checkout (with submodules)
+        uses: actions/checkout@v4
+        with:
+          submodules: recursive
+          fetch-depth: 0
+
+      - name: Install system dependencies
+        shell: bash
+        run: |
+          set -euo pipefail
+          sudo apt-get update
+          sudo apt-get install -y --no-install-recommends \
+            build-essential \
+            cmake \
+            ninja-build \
+            pkg-config \
+            libssl-dev \
+            gcovr
+
+      - name: Set up Rust (stable)
+        uses: actions-rust-lang/setup-rust-toolchain@v1
+        with:
+          toolchain: stable
+
+      - name: Configure (CMake, coverage)
+        shell: bash
+        run: |
+          set -euo pipefail
+          cmake -S . -B build-coverage -G Ninja \
+            -DSIDERUST_BUILD_DOCS=OFF \
+            -DCMAKE_BUILD_TYPE=Debug \
+            -DCMAKE_CXX_FLAGS="--coverage" \
+            -DCMAKE_EXE_LINKER_FLAGS="--coverage"
+
+      - name: Build tests
+        shell: bash
+        run: |
+          set -euo pipefail
+          cmake --build build-coverage --target test_siderust
+
+      - name: Run tests
+        shell: bash
+        run: |
+          set -euo pipefail
+          ctest --test-dir build-coverage --output-on-failure -L siderust_cpp
+
+      - name: Coverage (Cobertura XML)
+        shell: bash
+        run: |
+          set -euo pipefail
+          gcovr \
+            --root . \
+            --exclude 'build-coverage/.*' \
+            --exclude 'siderust/.*' \
+            --exclude 'qtty-cpp/.*' \
+            --exclude 'tempoch-cpp/.*' \
+            --exclude 'tests/.*' \
+            --exclude 'examples/.*' \
+            --xml \
+            --output coverage.xml
+
+      - name: Coverage (HTML)
+        shell: bash
+        run: |
+          set -euo pipefail
+          mkdir -p coverage_html
+          gcovr \
+            --root . \
+            --exclude 'build-coverage/.*' \
+            --exclude 'siderust/.*' \
+            --exclude 'qtty-cpp/.*' \
+            --exclude 'tempoch-cpp/.*' \
+            --exclude 'tests/.*' \
+            --exclude 'examples/.*' \
+            --html-details \
+            --output coverage_html/index.html
+
+      - name: Build coverage summary (Markdown)
+        uses: irongut/CodeCoverageSummary@v1.3.0
+        with:
+          filename: coverage.xml
+          badge: true
+          format: markdown
+          output: file
+
+      - name: Publish to Job Summary
+        shell: bash
+        run: cat code-coverage-results.md >> "$GITHUB_STEP_SUMMARY"
+
+      - name: Post coverage as PR comment
+        if: github.event_name == 'pull_request'
+        uses: mshick/add-pr-comment@v2
+        with:
+          message-path: code-coverage-results.md
+          repo-token: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Upload coverage HTML
+        if: always()
+        uses: actions/upload-artifact@v4
+        with:
+          name: coverage-html
+          path: coverage_html
+          retention-days: 7

examples/altitude_events_example.cpp

@@ -1,6 +1,7 @@
 /**
  * @file altitude_events_example.cpp
- * @brief Altitude windows, crossings, and culminations for Sun, Moon, and stars.
+ * @brief Altitude windows, crossings, and culminations for Sun, Moon, and
+ * stars.
  *
  * Usage:
  *   cmake --build build-make --target altitude_events_example
@@ -24,14 +25,15 @@ static const char* culmination_kind_name(CulminationKind k) {
 }
 
 static void print_utc(const UTC& utc) {
-    std::printf("%04d-%02u-%02u %02u:%02u:%02u",
-                utc.year, utc.month, utc.day,
+    std::printf("%04d-%02u-%02u %02u:%02u:%02u", utc.year, utc.month, utc.day,
                 utc.hour, utc.minute, utc.second);
 }
 
-static void print_periods(const char* title, const std::vector<Period>& periods, std::size_t max_items = 4) {
+static void print_periods(const char* title, const std::vector<Period>& periods,
+                          std::size_t max_items = 4) {
     std::printf("%s: %zu period(s)\n", title, periods.size());
-    const std::size_t n = (periods.size() < max_items) ? periods.size() : max_items;
+    const std::size_t n =
+        (periods.size() < max_items) ? periods.size() : max_items;
     for (std::size_t i = 0; i < n; ++i) {
         const auto s = periods[i].start().to_utc();
         const auto e = periods[i].end().to_utc();
@@ -46,7 +48,9 @@ static void print_periods(const char* title, const std::vector<Period>& periods,
     }
 }
 
-static void print_crossings(const char* title, const std::vector<CrossingEvent>& events, std::size_t max_items = 6) {
+static void print_crossings(const char*                       title,
+                            const std::vector<CrossingEvent>& events,
+                            std::size_t                       max_items = 6) {
     std::printf("%s: %zu event(s)\n", title, events.size());
     const std::size_t n = (events.size() < max_items) ? events.size() : max_items;
     for (std::size_t i = 0; i < n; ++i) {
@@ -60,15 +64,16 @@ static void print_crossings(const char* title, const std::vector<CrossingEvent>&
     }
 }
 
-static void print_culminations(const char* title, const std::vector<CulminationEvent>& events, std::size_t max_items = 6) {
+static void print_culminations(const char*                          title,
+                               const std::vector<CulminationEvent>& events,
+                               std::size_t                          max_items = 6) {
     std::printf("%s: %zu event(s)\n", title, events.size());
     const std::size_t n = (events.size() < max_items) ? events.size() : max_items;
     for (std::size_t i = 0; i < n; ++i) {
         const auto t = events[i].time.to_utc();
         std::printf("  %zu) ", i + 1);
         print_utc(t);
-        std::printf("  alt=%.3f deg  kind=%s\n",
-                    events[i].altitude.value(),
+        std::printf("  alt=%.3f deg  kind=%s\n", events[i].altitude.value(),
                     culmination_kind_name(events[i].kind));
     }
     if (events.size() > n) {
@@ -79,9 +84,9 @@ static void print_culminations(const char* title, const std::vector<CulminationE
 int main() {
     std::printf("=== Altitude Events Example ===\n\n");
 
-    const auto obs = MAUNA_KEA;
-    const auto start = MJD::from_utc({2026, 7, 15, 0, 0, 0});
-    const auto end = start + 2.0;
+    const auto   obs   = MAUNA_KEA;
+    const auto   start = MJD::from_utc({2026, 7, 15, 0, 0, 0});
+    const auto   end   = start + 2.0;
     const Period window(start, end);
 
     std::printf("Observer: Mauna Kea (lon=%.4f lat=%.4f h=%.0f m)\n",
@@ -94,7 +99,7 @@ int main() {
     // Sun examples.
     const auto sun_night = sun::below_threshold(obs, window, -18.0_deg, opts);
     const auto sun_cross = sun::crossings(obs, window, -0.833_deg, opts);
-    const auto sun_culm = sun::culminations(obs, window, opts);
+    const auto sun_culm  = sun::culminations(obs, window, opts);
     print_periods("Sun below -18 deg (astronomical night)", sun_night);
     print_crossings("Sun crossings at -0.833 deg", sun_cross);
     print_culminations("Sun culminations", sun_culm);
@@ -103,16 +108,18 @@ int main() {
     // Moon examples.
     const auto moon_above = moon::above_threshold(obs, window, 20.0_deg, opts);
     const auto moon_cross = moon::crossings(obs, window, 0.0_deg, opts);
-    const auto moon_culm = moon::culminations(obs, window, opts);
+    const auto moon_culm  = moon::culminations(obs, window, opts);
     print_periods("Moon above +20 deg", moon_above);
     print_crossings("Moon horizon crossings", moon_cross);
     print_culminations("Moon culminations", moon_culm);
     std::printf("\n");
 
     // Star examples.
     const auto& vega = VEGA;
-    const auto vega_above = star_altitude::above_threshold(vega, obs, window, 25.0_deg, opts);
-    const auto vega_cross = star_altitude::crossings(vega, obs, window, 0.0_deg, opts);
+    const auto  vega_above =
+        star_altitude::above_threshold(vega, obs, window, 25.0_deg, opts);
+    const auto vega_cross =
+        star_altitude::crossings(vega, obs, window, 0.0_deg, opts);
     const auto vega_culm = star_altitude::culminations(vega, obs, window, opts);
     print_periods("VEGA above +25 deg", vega_above);
     print_crossings("VEGA horizon crossings", vega_cross);
@@ -121,12 +128,10 @@ int main() {
 
     // Fixed ICRS direction examples.
     const spherical::direction::ICRS dir_icrs(279.23473_deg, 38.78369_deg);
-    const auto dir_above = icrs_altitude::above_threshold(
-        dir_icrs, obs, window, 30.0_deg, opts
-    );
-    const auto dir_below = icrs_altitude::below_threshold(
-        dir_icrs, obs, window, 0.0_deg, opts
-    );
+    const auto                       dir_above =
+        icrs_altitude::above_threshold(dir_icrs, obs, window, 30.0_deg, opts);
+    const auto dir_below =
+        icrs_altitude::below_threshold(dir_icrs, obs, window, 0.0_deg, opts);
     print_periods("Fixed ICRS direction above +30 deg", dir_above);
     print_periods("Fixed ICRS direction below horizon", dir_below);
 

examples/coordinate_systems_example.cpp

@@ -19,12 +19,12 @@ int main() {
     std::printf("=== Coordinate Systems Example ===\n\n");
 
     auto obs = ROQUE_DE_LOS_MUCHACHOS;
-    auto jd = JulianDate::from_utc({2026, 7, 15, 22, 0, 0});
+    auto jd  = JulianDate::from_utc({2026, 7, 15, 22, 0, 0});
 
     std::printf("Observer (Geodetic): lon=%.4f deg lat=%.4f deg h=%.1f m\n",
                 obs.lon.value(), obs.lat.value(), obs.height.value());
 
-    auto ecef_m = obs.to_cartesian<qtty::Meter>();
+    auto ecef_m  = obs.to_cartesian<qtty::Meter>();
     auto ecef_km = obs.to_cartesian<qtty::Kilometer>();
     std::printf("Observer (ECEF): x=%.2f m y=%.2f m z=%.2f m\n",
                 ecef_m.x().value(), ecef_m.y().value(), ecef_m.z().value());
@@ -34,11 +34,11 @@ int main() {
     // Vega J2000 ICRS direction.
     spherical::direction::ICRS vega_icrs(279.23473, 38.78369);
 
-    auto vega_ecl = vega_icrs.to<EclipticMeanJ2000>(jd);
+    auto vega_ecl    = vega_icrs.to<EclipticMeanJ2000>(jd);
     auto vega_eq_mod = vega_icrs.to<EquatorialMeanOfDate>(jd);
     auto vega_eq_tod = vega_icrs.to<EquatorialTrueOfDate>(jd);
-    auto vega_hor = vega_icrs.to_horizontal(jd, obs);
-    auto vega_back = vega_ecl.to<ICRS>(jd);
+    auto vega_hor    = vega_icrs.to_horizontal(jd, obs);
+    auto vega_back   = vega_ecl.to<ICRS>(jd);
 
     std::printf("Vega ICRS: RA=%.6f Dec=%.6f\n",
                 vega_icrs.ra().value(), vega_icrs.dec().value());
@@ -54,8 +54,7 @@ int main() {
                 vega_back.ra().value(), vega_back.dec().value());
 
     spherical::position::ICRS<qtty::AstronomicalUnit> target_sph_au(
-        120.0_deg, -25.0_deg, 2.0_au
-    );
+        120.0_deg, -25.0_deg, 2.0_au);
     auto target_dir = target_sph_au.direction();
     std::printf("Spherical ICRS position: RA=%.2f Dec=%.2f dist=%.3f AU\n",
                 target_sph_au.ra().value(),
@@ -64,12 +63,11 @@ int main() {
     std::printf("Direction extracted from spherical position: RA=%.2f Dec=%.2f\n\n",
                 target_dir.ra().value(), target_dir.dec().value());
 
-    cartesian::position::ICRS<qtty::Meter> target_cart_m(1.5e11, -3.0e10, 2.0e10);
+    cartesian::position::ICRS<qtty::Meter>            target_cart_m(1.5e11, -3.0e10, 2.0e10);
     cartesian::position::ICRS<qtty::AstronomicalUnit> target_cart_au(
         target_cart_m.x().to<qtty::AstronomicalUnit>(),
         target_cart_m.y().to<qtty::AstronomicalUnit>(),
-        target_cart_m.z().to<qtty::AstronomicalUnit>()
-    );
+        target_cart_m.z().to<qtty::AstronomicalUnit>());
 
     std::printf("Cartesian ICRS position: x=%.3e m y=%.3e m z=%.3e m\n",
                 target_cart_m.x().value(),