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Error is not showing on comparing when interface has optional variables #36602
Description
Code
interface A {
id?: number;
}
const a:A = {
id: 5
};
const testA: boolean = (a === 1); //works, but why?
interface B {
id: number;
}
const b:B = {
id: 5
};
const testB: boolean = (b === 1); //compiler error -> expected that also on A
Expected behavior:
An error on the compare line.
Actual behavior:
No error
Related Issues:
Activity
jcalz commentedon Feb 4, 2020
Context: relevant SO question
Search terms: weak type detection, comparison operators
Related issues:
#16047 - weak type detection PR
#17215 - comparability spec PR that I think never made it anywhere.
Looks like this behavior is intentional, at least if I can take #17215 for its word:
typescript-bot commentedon Feb 11, 2020
This issue has been marked as 'Question' and has seen no recent activity. It has been automatically closed for house-keeping purposes. If you're still waiting on a response, questions are usually better suited to stackoverflow.