Test coverage for native code WIP

Part of: https://git.lix.systems/lix-project/lix/issues/1186
2026-04-19 18:01:00 +00:00
parent 1e986c81ab
commit c76cf49629
10 changed files with 239 additions and 3 deletions
@@ -444,6 +444,18 @@ You can build it yourself:
 # xdg-open ./result/coverage/index.html
 ```

+Or, in a dev shell, set `-Dcoverage=true` when running `meson setup`.
+Coverage data goes into `build/profraw` when you run executables in the dev shell.
+Then, run `ninja -C build coverage-report` to produce an HTML report of coverage in `build/coverage/index.html` alongside a LLVM `.lcov` file.
+
+> [!NOTE]
+> We use the [llvm source-based coverage], which has better precision than using clang with gcov, which is debuginfo based (but likely worse performance, which is fine).
+>
+> It should be noted that Meson [allegedly has coverage support][meson-coverage], but it only supports gcov-style coverage, so we don't use it.
+
+[llvm source-based coverage]: https://clang.llvm.org/docs/SourceBasedCodeCoverage.html
+[meson-coverage]: https://mesonbuild.com/Unit-tests.html#coverage
+
 Metrics about the change in line/function coverage over time will be available in the future (FIXME(lix-hydra)).

 ## Add a release note {#release-notes}