fix(lines-before-block): Only trigger after ';', '}', '|', and '&'

[LukeAbby]

Fixes #1379 and #1343.

I initially went for a targeted fix that would only solve my issue, #1379, but I noticed that all punctuators didn't seem to me like reasonable places to insert a line before. As I had also been facing #1343 solving it was nice too.

Of course what "feels" right is obviously subjective so let me know if you want me to put this behind an option. I considered exposing lintedPunctuators as an option but it felt too granular. Disabling & could be useful to users of Prettier that want to set ignoreSameLine to false though. Specifically, Prettier really isn't fond of the formatting in this snippet:

type IntersectionDocumentation =
    & { someProp: number }
    /** Description. */
    & { otherProp: string };

And will format it like so:

type IntersectionDocumentation = { someProp: number } /** Description. */ & { otherProp: string };

Which I think looks terrible.

As a final note, currently the option checkBlockStarts is set to actually control linting after all punctuators because I noticed a number of tests expected it to work that way for more than just {, like the array test etc. This makes it a bit of a misnomer but it appears it was already a bit of a misnomer.

[brettz9]

This LGTM. Just the suggested tweak on using a Set.

[LukeAbby]

Thanks for the review! Bad habit of mine to not use a Set. Probably comes from knowing that Set#has is slower than Array#includes for small array but it leads to clearer code and that's what's most important.

[github-actions]

🎉 This issue has been resolved in version 50.6.13 🎉

The release is available on:

• GitHub release
• npm package (@latest dist-tag)

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