Bindings where `@scope` has same name as module can result in runtime errors

[mediremi]

When a binding's @scope has the same name as a module, the binding's scope is shadowed by the module:

module URL = {  
  @val @scope("URL")
  external revokeObjectURL: string => unit = "revokeObjectURL"
}

URL.revokeObjectURL("some url")

let URL = {};

URL.revokeObjectURL("some url");

[cknitt]

I think this is not a v12 issue per se, it's just that v12 doesn't escape URL with $$ anymore.

If the module name is different, the same problem exists in v11:

module URRL = {  
  @val @scope("URRL")
  external revokeObjectURL: string => unit = "revokeObjectURL"
}

URRL.revokeObjectURL("some url")

https://rescript-lang.org/try?version=v11.1.4&module=esmodule&code=LYewJgrgNgpgBAVQEpIDJwLxwN5zgKDwAEA3AQyjiIGcBjEABxgAoAiZNVgSkLhgA8ALjABOAOwpwRMEiADWMAPIAjAFYxag5KgBccaoJEBLMQHNMAPjgQxRwZjitpshSvWbtrfAF98+DqgAdM7ySmoaWmhs1CDA8BAiUNz4QA

[mediremi]

Ah I didn't read the breaking changes section of v12.0.0-alpha.1 carefully enough - I see now that since https://github.com/rescript-lang/rescript/pull/6831 we're not escaping browser globals anymore.

I'll update this issue title and description to not be v12 specific 👍

[cometkim]

The problem is not because of @scope, but the module name.

[cometkim]

I see. It should be something like:

let URL$1 = {};

URL.revokeObjectURL("some url");

export {
  URL$1 as URL,
}

[cometkim]

Workaround (IMO the correct resolution):

module URL = {  
  @val @scope("globalThis.URL")
  external revokeObjectURL: string => unit = "revokeObjectURL"
}

URL.revokeObjectURL("some url")

[cknitt]

Although this can be broken in basically the same way:

module URL = {  
  @val @scope("globalThis.URL")
  external revokeObjectURL: string => unit = "revokeObjectURL"
}

let globalThis = 0

URL.revokeObjectURL("some url")

[cometkim]

globalThis should be mangled by default.

The output in v12 is:

let URL = {};

globalThis.URL.revokeObjectURL("some url");

let $$globalThis = 0;

export {
  URL,
  $$globalThis,
}
/*  Not a pure module */

[zth]

One downside of leveraging globalThis is that it doesn't look handwritten. But I guess there's no other good way around this.

[cometkim]

Maybe we can make it as a standard like @globalScope(..) ?

[zth]

Are there any alternative ways around this? Could we detect when this unintended clash happens and only then emit globalThis?

[cknitt]

globalThis should be mangled by default.

Ah, right, it is mangled in v12, but not v11.