Adding Valgrind workflow for GitHub Actions

[sjoblomj]

This PR adds support for Valgrind, a memory leak detector.

The PR also adds tests for the about and version subcommands. While those tests are pretty useless in themselves, they do complete the test suite for all subcommands, which also means Valgrind gets to check all subcommands.

The PR adds

• Github Actions Workflow, that runs Valgrind on every PR, and automatically posts a comment when there are memory leaks in it.
• Convenience script for running Valgrind locally in Docker.
• Tests for the about and version subcommands.

Convenience script

This will setup Valgrind in Docker, run the whole test suite and check for memory leaks in the code paths that the test suite covers:

./scripts/run_valgrind_tests.sh --docker

Running a specific command

One can also invoke Valgrind for a specific command (in this case mpqcli list wow-patch.mpq):

# Build image
docker build --build-arg USER_ID=$(id -u) --build-arg GROUP_ID=$(id -g) -t mpqcli-valgrind -f Dockerfile.valgrind .

# Run image against the list subcommand and the wow-patch.mpq file
docker run --rm \
  -v $(pwd)/path/to/directory/with/test/mpqs:/mpqcli/test/data:ro \
  mpqcli-valgrind \
  valgrind --leak-check=full --show-leak-kinds=all \
  ./build/bin/mpqcli list wow-patch.mpq

(I created this PR using AI - it all seems sensible to me, but I am not an expert at either Valgrind nor GitHub Actions Workflows)

[sjoblomj]

One of the steps in the GitHub Workflow will post comments on the PR if it contains memory leaks. But it currently does not have permissions to do so. You'll need to grant those permissions to the repo. AI says:

1. Go to your repository on GitHub: https://github.com/TheGrayDot/mpqcli
2. Click Settings (top right)
3. In the left sidebar, click Actions → General
4. Scroll down to Workflow permissions
5. Select "Read and write permissions" (instead of "Read repository contents and packages permissions")
6. Check the box "Allow GitHub Actions to create and approve pull requests"
7. Click Save

[thomaslaurenson]

Hey @sjoblomj - sorry for the late reply. I haven't had time to look at this PR yet. I would like to set up Valgrind locally and do some testing before I review - hope that is OK.

[sjoblomj]

@thomaslaurenson: I gave this PR some more attention, and I think it is leaner and cleaner than before.

A comment will be automatically created in the PR when there are memory leaks. As I described in an earlier comment, you'd need to set up permissions for that to happen.

As it stands now, the checks are failing because of lack of permissions, and because there are memory leaks in the code base. PR #173 fixes the latter.