How to run diff-slider tests

The idea is to use https://github.com/mhagger/diff-slider-tools to create slider information for use to generate a test which invokes our own implementation and compares it to Git itself. Follow these instructions to set it up.

1. DIFF_SLIDER_TOOLS=/your/anticipated/path/to/diff-slider-tools
2. git clone https://github.com/mhagger/diff-slider-tools $DIFF_SLIDER_TOOLS
3. pushd $DIFF_SLIDER_TOOLS
4. Follow these instructions to generate a file containing the slider information. Be sure to set the repo variable as it's used in later script invocations.
   • Note that get-corpus must be run with ./get-corpus.
   • You can use an existing repository, for instance via repo=git-human, so there is no need to find your own repository to test.
   • The script suite is very slow, and it's recommended to only set a range of commits, or use a small repository for testing.

Finally, run the internal-tools program to turn that file into a fixture called make_diff_for_sliders_repo.sh.

# run inside `gitoxide`
popd
cargo run --package internal-tools -- \
  create-diff-cases \
    --sliders-file $DIFF_SLIDER_TOOLS/corpus/$repo.sliders \
    --worktree-dir $DIFF_SLIDER_TOOLS/corpus/$repo.git/ \
    --destination-dir gix-diff/tests/fixtures/

Finally, run cargo test -p gix-diff sliders -- --nocapture to execute the actual tests to compare.