Array destructuring

[despairblue]

Neither

let [route,] = 'post?id=1234'.split('?') // Unexpected trailing comma.

nor

let [route, ] = 'post?id=1234'.split('?') // Unexpected trailing comma. + A space is required after ','.

is allowed.

Whereas this

let [, parameters] = 'post?id=1243'.split('?')

is allowed.

Whether doing this is a good idea is probably disputable, but it is legal syntax.

[feross]

standard is a code linter – the whole purpose is to prevent legal syntax that's confusing and/or likely to be a bug. :)

The first two examples let [route,] = ... and let [route, ] = ... are better written as let [route] = .... The comma does nothing, and standard disallows trailing commas in other situations, so this is consistent.

The last example let [, parameters] = ..., actually does something useful. It selects the second item in the array. Unless I'm missing something, I can't see a reason to disallow this.

[despairblue]

@feross duh, yeah, I missed the forest for the trees while refactoring, my bad 😅

[feross]

No worries!