[bug][scope analysis] A symbol has two owner scopes in the same time

[hyf0]

(() => {
	function a() {
		b()
	}
	{
		var b = () => {}
	}
	a()
})()

I notice that symbol b belong to two owner scopes after the sematic analysis in [email protected].

[Dunqing]

I put the code in the playground

[Boshen]

Scope1 (ScopeFlags(StrictMode | Top)) {
  Scope2 (ScopeFlags(StrictMode | Function | Arrow)) {
    Bindings: {
      a (SymbolFlags(FunctionScopedVariable))
      b (SymbolFlags(FunctionScopedVariable))
    }
    Scope3 (ScopeFlags(StrictMode | Function)) {
    }
    Scope4 (ScopeFlags(StrictMode)) {
      Bindings: {
        b (SymbolFlags(FunctionScopedVariable))
      }
      Scope5 (ScopeFlags(StrictMode | Function | Arrow)) {
      }
    }
  }
}

The logic here is that these scopes have the variable b. There is no owning logic.

[hyf0]

The logic here is that these scopes have the variable b. There is no owning logic.

So, is this logic expected? A binding could belong to many scopes in the same time.

If this is expected, what's the right way to get a binding's owner scope(the scope that store it in the first place)?

[hyf0]

I put the code in the playground

Wow I didn't thought the playgound is already support visulize the scopes. This is very useful.

If the playgound could aslo print out the symbol id for symbols, it will be very useful to distinguash symbols that has the same name.

[hyf0]

The scope output for input

(() => {
        var b;
	function a() {
		b()
	}
	{
		var b = () => {}
	}
	a()
})()

is

Scope1 (ScopeFlags(StrictMode | Top)) {
  Scope2 (ScopeFlags(StrictMode | Function | Arrow)) {
    Bindings: {
      b (SymbolFlags(FunctionScopedVariable))
      a (SymbolFlags(FunctionScopedVariable))
    }
    Scope3 (ScopeFlags(StrictMode | Function)) {
    }
    Scope4 (ScopeFlags(StrictMode)) {
      Scope5 (ScopeFlags(StrictMode | Function | Arrow)) {
      }
    }
  }
}

I'm not sure if this is right or wrong, but it does feel weird to me.

[Dunqing]

If the playgound could aslo print out the symbol id for symbols, it will be very useful to distinguash symbols that has the same name.

The symbol view may be useful for you. When you hover over the span, the b symbol has been highlighted

[Dunqing]

If this is expected, what's the right way to get a binding's owner scope(the scope that store it in the first place)?

I think we can't get the binding's owner scope now.

Although the b symbol contains the symbol in both its scope and its parent scope, that symbol id and node id both point to the same one, I don't know if this will help you

[hyf0]

If this is expected, what's the right way to get a binding's owner scope(the scope that store it in the first place)?

I think we can't get the binding's owner scope now.

Although the b symbol contains the symbol in both its scope and its parent scope, that symbol id and node id both point to the same one, I don't know if this will help you

Yeah, I know that. I just want to know if the current behavior is correct. If it's expected, I will try to solve my problems in user land. If it's not, it becomes a bug that oxc needs to fix.

[Dunqing]

I think that is expected. But need @Boshen to confirm this.

[Boshen]

@hyf0 Let me investigate and get back to you. var hoisting logic is complicated :-)

[Dunqing]

After the communication, we think the result is expected.