Typescript: Implements self is not show problems

[belozer]

TypeScript Version: 3.7.5

Search Terms: Implements self

Code

Case 1

interface Test {
    foo(): void;
}
class Test { }

new Test().foo(); // Expected Error

Case 2

class Test2 implements Test2 {} // Expected Error

Case 3

// Case 3
interface Test3 {
    foo(): string
}

class Test3 implements Test3 {  // Expected Error
    bar() { return '' }
}

new Test3().foo();  // Expected Error

Actual behavior:
No errors...

Playground Link:
Playground

Related Issues:
https://github.com/Microsoft/TypeScript/issues/9699#issuecomment-232477522

[RyanCavanaugh]

These are all the intended behavior, as per the comment you linked.

[typescript-bot]

This issue has been marked 'Working as Intended' and has seen no recent activity. It has been automatically closed for house-keeping purposes.

[artalar]

TS is great, but runtime error for type-safe code - is a wrong =(