Fix staged file renamed with changes showing no diff

[ssigwart]

• Closes Changes from renamed files are ignored #6014

Description

Fixes the case where a staged file is moved and modified. Previously, it would say it was moved with no changes.

Screenshots

[tidy-dev]

@ssigwart Thanks for this contribution. I apologize for the long delay in review (small team, pr's are as we can get to them). I understand if you do not want to pick this back up after so much time. But if you do, here is some feedback:

I believe it is fairly non-invasive approach to having better messaging and appears to work as expected. I have left some code-base stylistic comments. Also, I can tell that if the CI had triggered, the linter would have failed. Thus, to get this PR another review, we will need to bring it up to date with development, address the pr suggestions, and run yarn:lint:fix. At that point, I will do more testing.

As said above, totally understand if you do not want to pick this back up. If that is the case we will close it in a couple of weeks.

[ssigwart]

Thanks, @tidy-dev. I rebased and applied the updates you suggested. The GitHub actions don't run without approval for me, but I ran yarn lint and yarn lint:fix locally.

[tidy-dev]

@ssigwart We have some failing unit test since the status module has changed. Can you address those?

To run unit tests, use yarn test:unit.
To only run unit tests for only one of those files, you can run something like yarn test:unit log to do the log-test file and yarn test:unit status for the status-test file.

[ssigwart]

@tidy-dev, I fixed them. Thanks for the pointers on how to run the tests that failed.

[ssigwart]

@tidy-dev, I noticed that the unit tests ran today and there were some lint errors, so I ran yarn lint:fix and pushed a new commit.

[tidy-dev]

Works as expected. Thank you!

[ssigwart]

Thanks for reviewing and merging, @tidy-dev!