Destructuring assignments are producing errors with noImplicitAny

[thebanjomatic]

I found an issue in the current nightly builds relating to destructuring assignments with noImplicitAny enabled. The actual code was more complicated, but it can be simplified to the following:

let [a, b, c] = [1, 2, 3];

The variables appear to be typed correctly on hover, however, 3 errors are produced inside the assignment stating that a, b, and c have an implicit type of any.

It can be silenced by the following, but that's not ideal:

let [a, b, c] = <[number, number, number]>[1, 2, 3];

TypeScript Version:

Searching backwards, it first appears in:

• nightly (1.9.0-dev.20160409)

Expected behavior:

There shouldn't be an implicit any error in this case.

Actual behavior:

An erroneous error is produced.

[mhegazy]

looks like a regression from #6935

[thebanjomatic]

@sheetalkamat Any update on this issue? I came across the problem again when trying to build my code-base with the 2.0 beta.

[AlexGalays]

This bug is going to be encountered fairly frequently using TS 2.0 beta