🐞[BUG]: 'NGXS_SELECTOR_META' of undefined at app init after ng9/ngxs3.6 update > better error message

Since newer Angular versions emit ES2015 and not ES5 (where classes are downgraded to functions which are hoisted and might be used immediately), error messages become more meaningful. Classes are also hoisted, but might be used only after the code evaluation.

Testing it with Angular 11 and it throws Cannot access 'CurrentUserState' before initialization because this is how it looks like after the compilation:

class AppComponent {}

class CurrentUserSelectors {}

__decorate([Selector([CurrentUserState]), CurrentUserSelectors, "ips", null);

class CurrentUserState {}

It throws Cannot read property 'NGXS_SELECTOR_META' of undefined because ES5 variable is hoisted and equals undefined if accessed before the initialization:

var CurrentUserSelectors = function() {};

__decorate([Selector([/* undefined here */ CurrentUserState]), CurrentUserSelectors, "ips", null);

var CurrentUserState = function() {};

The createSelector approach works since it only captures the CurrentUserState reference, but doesn’t access it immediately as opposed to @Selector() decorator.

I’m closing it as not an issue for now, since I don’t see any issue in our codebase which likely might be solved.

@stgrosshh would it be possible to provide more information or a repro?

I will try to set up a small example showing the problem in a repo