Add coverage report generation for tests

[sandrobonazzola]

Added targets to Makefile for getting a coverage report from the unit tests.

Example report:

[mwperina]

The idea is OK, but me personally I don't like using Makefile more and more, we agreed to use meson in the past, so we should stick to it and if really needed provide some shell scripts to ease execution and extend our dependency on Makefiles

[engelmi]

The Makefile we keep only for more complex or repetitive commands, otherwise its best to directly use meson. Here the basic flow for getting the test coverage is roughly like this:

meson setup builddir    # if already setup, this is a noop
meson configure builddir -Db_coverage=true
meson test -C builddir
ninja coverage-html -C builddir/src/libhirte

I'd prefer doing a meson configure over a meson setup for setting the option since the latter will have no effect if I've run meson setup with a different (or no) value for the option before. We could also set -Db_coverage=true as default - not sure if that has any negative impact, though.
In this project, it makes only sense to collect the coverage from meson test for the libhirte directy - the other parts will probably have to be tested via integration tests (unfortunately).

I'd only have the test-coverage make target which bundles the snippet above. And have the changes in the readme, of course. What do you think? @sandrobonazzola @mwperina

[engelmi]

It would also be great to export the test coverage as an artifact in the gh action. For this, I think we need to

• add the meson configure before the make call here:
  https://github.com/containers/hirte/blob/main/.github/workflows/unit-tests.yml#L26
• and upload the artifact in the step below

[sandrobonazzola]

It would also be great to export the test coverage as an artifact in the gh action.

I was preparing this as follow up to this PR:

index e481a36..f80a67f 100644
--- a/.github/workflows/unit-tests.yml
+++ b/.github/workflows/unit-tests.yml
@@ -17,13 +17,18 @@ jobs:
       - name: Checkout sources
         uses: actions/checkout@v3
 
+      - name: Install coverage tools
+        run: |
+          sudo apt-get install lcov -y
+          pip install html2text
+
       - name: Building hirte
         run: |
-          make build
+          make build-coverage
 
       - name: Running unit tests
         run: |
-          make test-with-valgrind
+          make test-with-valgrind-coverage
 
       - name: Upload unit test logs
         if: always()
@@ -31,3 +36,15 @@ jobs:
         with:
           name: unit-test-logs
           path: ./builddir/meson-logs/testlog-valgrind.txt
+
+      - name: Upload coverage HTML artifact
+        uses: actions/upload-artifact@v3
+        with:
+          name: coverage
+          path: builddir/meson-logs/coveragereport
+          if-no-files-found: error
+
+      - name: Report coverage results
+        run: |
+          cd builddir/meson-logs/coveragereport/
+          html2text --ignore-images --ignore-links -b 0 --bypass-tables index.html >> $GITHUB_STEP_SUMMARY

[sandrobonazzola]

I'd only have the test-coverage make target which bundles the snippet above. And have the changes in the readme, of course. What do you think? @sandrobonazzola @mwperina

ok, what about the test with valgrind?

[mwperina]

LGTM

[engelmi]

LGTM