Weird behavior with await

[julien-f]

(async function () {
  // Missing space before keyword "await".
  !await true

  // Unexpected space after unary operator "!".
  ! await true

  // Works.
  !(await true)
})()

[feross]

This is caused by two rules that make sense alone but conflict in this situation, and other situations like it.

I opened as an issue on eslint to get their feedback: eslint/eslint#3878

[julien-f]

It does not work either with string interpolation:

(async function () {
  console.log(`${await 'foo'}`)
})()

So your proposal to disable this rule for unary operators does not really make sense.

await is very different from other keywords (if, return, etc.) as it is part of an expression and IMHO it should be treated differently, and the same goes for yield.

[LinusU]

I found another strange behaviour which I think is the same as this:

const [bread, butter] = [await breadPromise, await butterPromise]

Missing space before keyword "await".

As you can see I don't use initial spaces in arrays ([a, b] vs. [ a, b ]) which standard is totally fine with, so it seems weird that I need to do it when using await.

[matjaz]

any updates on this?

[feross]

This issue is similar to #387. I'll repeat what I posted there earlier:

This issue is caused by the keyword spacing rules that we have enabled conflicting with other spacing rules that we have enabled.

Fortunately, the next version of eslint (v2) (which will ship in standard v6) has a new, better rule keyword-spacing which doesn't check conditions which are handled by other rules.

From the docs for keyword-spacing:

This rule is designed carefully to not conflict with other spacing rules. Basically this rule ignores usage of spacing at places that other rules are catching. So the following patterns are considered not problems.

This is fixed on the v6 branch and will be released as standard v6 soon.