undefineds not stated

[chpio]

Hi,

undefineds types seem to be missing in this lib.

For example, the getSelectedDocument function docs reads as:

The selected Document or undefined if no document is open.

But the undefined is still missing in the ty:

getSelectedDocument(): Document;

[qjebbs]

There is no need to write Document | undefined, you can try to find out what is the type of d:

let d = getSelectedDocument()
function getSelectedDocument(): Document | undefined {
    return
}

[chpio]

your code example seems to be broken. Why is there no need to define an undefined return type if it's part of the return type?

[qjebbs]

@chpio I mean, what does it help if no lint issue raised below?

let d = getSelectedDocument()
// no lint issues
console.log(d.pages)
function getSelectedDocument(): Document | undefined {
    return undefined
}

[chpio]

you have to enable strictNullChecks in compilerOptions in your tsconfig. They should have enabled it by default, but i guess they refused to do so for compatibility/portability reasons with js (ts being js with optional types). Anyway... NULL being the Worst Mistake in Computer Science should encourage you to enable strictNullChecks and opt-out of implicit null & undefined.

[qjebbs]

That makes sense, you are a TS expert. I'll add | undefined everywhere if possible, and welcome PR if you found more issues.

PS: strictNullChecks is not specified, and the default is false here (TS 4.1.2). I never noticed it.

[chpio]

That makes sense, you are a TS expert.

Nah, im somewhat of an expert in rust. Rust doesn't have nulls for exactly that reason.