Post

Convince me I am wrong: This should not be a type error, right? - I asserted it’s an object - I am using `?.` for property access www.typescriptlang.org/play/#code/G...

`typeof null === 'object'` so I think you might need to check for null. And then I tend to find 'a' in x more reliable in TS

Right, I know how to work around it. But I am asking: Shouldn’t this be accepted by the type checker (because `null?.a` is perfectly valid)

The issue isn't the null. `object?.a` is not valid!

Why not?

That's just how the object type works in typescript. You're asserting it's an object and then trying to use it like `any` but it's not equivalent.

I disagree and think the type error is correct. How do you propose to change the behaviour? What type should typeof === 'object' give you? It appears that you want it to be `any`

I'm proposing that `o?.x` is not a *type error* if `x` does not exist on o's type.

Your code is not checking if the property x exists on o, it's checking the value of the type is a string. The property could exist but be undefined. The correct way to check if a property exists is via 'x' in o.