Avoid line ending inconsistencies

[ddbeck]

Prompted by #3224, this PR replaces line endings and some other invisible characters in the linter diff output with their respective escape sequences.

For example, if you have CRLF line endings in a JSON file, then the resulting linter diff makes it seem as if both the expected and actual lines are the same.

Unfortunately, I suspect my implementation is rather naive. I really want to believe there's some kind of regex trickery that would generalize this to any invisible character. I did some fruitless searching, then gave up and did the simplest thing that worked for me. 🤷‍♂️

[connorshea]

@ddbeck This article might be helpful: https://www.edwardthomson.com/blog/advent_day_1_gitattributes_for_text_files.html

Essentially, if we add a .gitattributes file like this it should have git force LF line endings on every new/edited JSON file committed to the repository:

*.json text eol=lf

[ddbeck]

@connorshea thanks for the link! I think that's a good idea too. I've added that to the PR and updated the title to reflect the slightly broadened scope of the changes here. Thank you!

[Elchi3]

This looks like a great idea to me. The code looks good to me, too.
Do all files pass right away with this additional test? I'm surprised. Do we need a rebase against latest master to see if our HEAD is all green as well?

[ddbeck]

Fortunately, there's not a new test here. It only changes the output of an existing test. Also fortunately, I did test renormalizing the line endings, and all of the JSON currently in the repo have the proper line endings already. I just re-tested this on master and we're good there (as of five minutes ago, at least).

[Elchi3]

Ahh yes, this is no new test strictness, but reporting is improved!

Previously, this would have been reported as:

  Style – Error on line #1
    Actual:   {
    Expected: {

And now it is reported as:

  Style – Error on line #1
    Actual:   {\r
    Expected: {

Sorry for being slow! Just getting back to work after the holidays 😆

[Elchi3]

Love this, it came up a few times in PRs already I think. Great work @ddbeck and thanks for the helpful comments everyone!

[ddbeck]

Good idea to have some sample output in here, @Elchi3. I don't know why I didn't think of that. 🤦‍♂️ But yes, that is exactly right. And welcome back!