test: add end-to-end test for coverage hooks

Runs bashunit on fixture file with coverage enabled to verify
the complete flow works correctly, including hook coverage attribution.

Author: Chemaclass

tests/acceptance/coverage_hooks_test.sh

@@ -4,6 +4,7 @@
 function set_up_before_script() {
     TEST_ENV_FILE="tests/acceptance/fixtures/.env.default"
     LCOV_FILE="$(bashunit::temp_file "lcov-output")"
+    LCOV_FILE_EXTERNAL="$(bashunit::temp_file "lcov-external")"
 }
 
 function test_coverage_includes_src_hits_from_setup_hook() {
@@ -27,3 +28,21 @@ function test_coverage_includes_src_hits_from_setup_hook() {
     assert_contains "SF:$(pwd)/src/" "$lcov"
     assert_contains "DA:" "$lcov"
 }
+
+function test_coverage_hooks_via_external_bashunit() {
+    # Run bashunit on fixture with coverage enabled and verify hook code is tracked
+    local output
+    output=$(BASHUNIT_COVERAGE=true \
+             BASHUNIT_COVERAGE_PATHS="src/" \
+             BASHUNIT_COVERAGE_REPORT="$LCOV_FILE_EXTERNAL" \
+             ./bashunit tests/acceptance/fixtures/test_coverage_hooks.sh --simple 2>&1)
+
+    assert_successful_code
+
+    # Verify LCOV file was created with coverage data
+    assert_file_exists "$LCOV_FILE_EXTERNAL"
+    local lcov
+    lcov="$(cat "$LCOV_FILE_EXTERNAL" 2>/dev/null)"
+    assert_contains "SF:" "$lcov"
+    assert_contains "DA:" "$lcov"
+}