Arbitrary number properties are allowed

[vkurchatkin]

This type-checks:

type O = {};

function stuff(o: O) {
  const b = o[0].ff.ffa
}

o[0] behaves as it it was declared as any

[vkurchatkin]

This is still an issue.

[JohnyDays]

I think, if you want this to type-check you have to seal the object. E.g type O = { [key: string]: void };

[vkurchatkin]

Nope, this is definitely a bug, for example changing [0] to ['0'] fixes the problem

[gkz]

Fixed in 80ca16f