Compile does not produce an error when parameters in overriding class method in child class have narrower type than the parameters of this method in the parent class about typescript

[MartinJohns]

This is working as intended. There's even a section in the FAQ about this, and the behavior is required for some types (e.g. Arrays). Note that strictFunctionTypes applies to functions, not methods.

[edrennikov]

But as provided in the example above there is obviously an error in the code which can be caught at compile time.

[MartinJohns]

Yes, that's true. But it's still working as intended. TypeScripts type system is not fully sound (and it's not intended to).

Your intended change would break a whole lot of other stuff. See also #57783 for more information.

[edrennikov]

TypeScripts type system is not fully sound (and it's not intended to)

That's sad 😕 Another broken dream in software development 🥲