Update: Add a fixer for dot-location

[not-an-aardvark]

What is the purpose of this pull request? (put an "X" next to item)

[ ] Documentation update
[ ] Bug fix (template)
[ ] New rule (template)
[ ] Changes an existing rule (template)
[x] Add autofixing to a rule
[ ] Add a CLI option
[ ] Add something to the core
[ ] Other, please explain:

Please check each item to ensure your pull request is ready:

• I've read the pull request guide
• I've included tests for my change
• I've updated documentation for my change (if appropriate)

What changes did you make? (Give an overview)

This adds an autofixer for dot-location.

Given a MemberExpression where the dot is in the wrong location, the fixer will move the dot to the correct location. All comments between the object and the property are preserved.

/* eslint dot-location: [2, "property"] */

foo.
  bar;

baz. /* comment */
  qux;

// gets fixed to:

foo
  .bar;

baz /* comment */
  .qux;

/* eslint dot-location: [2, "object"] */

foo
  .bar;

5
  .toExponential();

// gets fixed to:

foo.
  bar;

5 .
  toExponential();

// (A space is added after `5` to ensure that the dot isn't parsed as a decimal point)

Is there anything you'd like reviewers to focus on?

I marked this as fixable: "code", but should it be fixable: "whitespace" instead since it doesn't change the AST?

[mention-bot]

@not-an-aardvark, thanks for your PR! By analyzing the annotation information on this pull request, we identified @vitorbal, @gcochard and @pedrottimark to be potential reviewers

[eslintbot]

LGTM

[platinumazure]

I think fixable: code is correct since you are not just adding or removing whitespace, but tokens as well.

[gcochard]

There's currently no functional difference between code and whitespace, but FWIW I'd go with whitespace as you're not modifying the AST.

[platinumazure]

We've used fixable: "code" when adding or removing parentheses (including in no-extra-parens, where we knew the AST would be unmodified). Maybe someone else on the team will explain it better, but to me, as soon as you add/remove/move a token, even for an equivalent AST, it's a code change.

[not-an-aardvark]

The reasoning in this case would be that we're not actually changing any tokens, either; we're basically changing the amount of whitespace that appears before and after the dot.

(That said, we are also moving comments around, so it's not just whitespace.)

[mysticatea]

Thank you for this PR!

I will be a champion for this change.

• I think good that dot-location also has autofix since very similar comma-style has autofix.

By the way, comma-style is fixable: "code".

[mysticatea]

A memo for me: /^\d*$/ will be replaced by astUtils.isDecimalInteger after #7185 is merged.

[not-an-aardvark]

#7185 is merged now, so I rebased and switched to astUtils.isDecimalInteger.

[eslintbot]

LGTM

[kaicataldo]

LGTM.
@eslint/eslint-team Looks like we need one more supporter.

[vitorbal]

I'll support this! 👍

[nzakas]

LGTM