Change quote-props rule to "consistent-as-needed"

[wincent]

I just got bitten by this while preparing this PR.

Basically, given an object containing some version numbers properties:

{
  '6.2': true,
  '7.0': true,
  '7.1': true,
}

we currently have ESLint configured via "quote-props" to require quotes around property names "as-needed"; producing this:

{
  6.2: true,
  '7.0': true,
  7.1: true,
}

This looks pretty terrible. I noticed that Prettier didn't have an opinion on this, so I changed them all to skip the quotes:

{
  6.2: true,
  7.0: true,
  7.1: true,
}

of course, that is wrong too, because 7.0 actually gets stringified to '7', meaning the object is equivalent to:

{
  '6.2': true,
  '7': true,
  '7.1': true,
}

This breaks checks of the form if (object['7.0'] === true). So I added a lint suppression and put strings back on all the keys, but we should just configure ESLint to use "consistent-as-needed" instead. The docs) describe it like so:

requires quotes around all object literal property names if any name
strictly requires quotes, otherwise disallows quotes around object
property names

Test plan: tweak my local copy of eslint-config-liferay in the repo with the PR I linked at the top and confirm that all-quotes are enforced in that object but not in other places. It's not a total bed of roses, unfortunately. I found that if you start with an object like this:

{
  a: 1,
  'b-c': 2,
}

it will get changed to:

{
  "a": 1,
  'b-c': 2,
}

on the bright side, if you then change it to use single quotes, it stays that way. Closest ticket I can find for an issue like this is:

microsoft/vscode-eslint#209

So, it's a wrinkle, but I still think we're better off with this change than without it.

Closes: https://github.com/liferay/eslint-config-liferay/issues/38

[wincent]

Note: don't want to merge this until Prettier 1.17 comes out, otherwise we'll have a conflict:

• Early report of conflict: Consistently add quotes to object keys prettier/prettier#838
• PR adding option that aligns with "consistent-as-needed": Add an option to modify when Prettier quotes object properties prettier/prettier#5934 — currently merged but not yet released.

[wincent]

Prettier 1.17 is out, so I am going to try this out.

[wincent]

Prettier 1.17 is out, so I am going to try this out.

Tried it, but there is still a bug, so probably best to hold off until it is resolved:

prettier/prettier#6064

[wincent]

At last, looks like we will be able to merge this with the next Prettier release, thanks to: prettier/prettier#8508

[jbalsas]

How did you remember about this?

[wincent]

I'm subscribed to the Prettier issue, so I go an email about it. Wasn't that hard to remember the connection. 😁