Fix #41800 correctly.

[ShuiRuTian]

Fixes #41816

[weswigham]

Hm. The text comparison is a little too specific - for example, what if

declare module m {
  namespace a.b {
    class c {}
  }
  export = a.b;
}

? I think we need to do a symbol identity comparison here. In the checker, this'd be easy using some resolveEntityName or getSymbolOfNode machinery - in moduleSpecifiers.ts it's maybe a bit more awkward? There's a getSymbolIfSameReference function in the checker for seeing if two symbols really refer to the same thing that is what I'd have considered using if it was available. Maybe we need some more context from the checker available? Or just more internals exported from the checker?

[ShuiRuTian]

Hm. The text comparison is a little too specific - for example, what if

declare module m {
  namespace a.b {
    class c {}
  }
  export = a.b;
}

? I think we need to do a symbol identity comparison here. In the checker, this'd be easy using some resolveEntityName or getSymbolOfNode machinery - in moduleSpecifiers.ts it's maybe a bit more awkward? There's a getSymbolIfSameReference function in the checker for seeing if two symbols really refer to the same thing that is what I'd have considered using if it was available. Maybe we need some more context from the checker available? Or just more internals exported from the checker?

it is a good sugestion, but I am little worried about something
these functions(getsymbolofNode) are in the function createTypeChecker, so they could not be exported directly. What about match namespace directly?
Find the namespace unitil it is not nested namespace -- if module symbol is "b"(it is a nested namespace) and we find its parent "a"(it is namespace and not nested), so the path is "a.b", which matches default export("a.b")

[weswigham]

Nah, I'm pretty sure you gotta do symbol resolution and matching - otherwise you'll miss renames like

declare module "m" {
  namespace a.b {
    class c {}
  }
  import d = a.b;
  export = d;
}

[ShuiRuTian]

Thanks a lot for the kind suggestion
Now using getSymbolAtLocation and getAliasedSymbol to get the original symbol of the default export , then compare it with moduleSymbol, is this way OK? Did I miss something again?

[weswigham]

This looks pretty good to me - just two small nits.