Type 'string' cannot be used to index type 'EffectsMetadata<T>'

[alex-okrushko]

I'm submitting a...

[ ] Regression (a behavior that used to work and stopped working in a new release)
[ X ] Bug report  
[ ] Feature request
[ ] Documentation issue or request

What is the current behavior?

I'm syncing the latest ngrx into Google and I'm getting the build error:

metadata[propertyName] = { dispatch };
~~~~~~~~~~~~~~~~~~~~~~
third_party/javascript/ngrx/modules/effects/src/effects_metadata.ts(56,5): error TS2536: Type 'string' cannot be used to index type 'EffectsMetadata'.

Expected behavior:

I think it doesn't like the fact that propertyName cannot be narrowed down to keyof T.
The fix would be to use less fancy Indexable EffectsMetadata, e.g. this works:

export type EffectsMeta = {
  [key: string]:
    | undefined
    | {
        dispatch: boolean;
      }
};

The other option is to use ES6 Map altogether instead of Indexable.

Thoughts?

Minimal reproduction of the problem with instructions:

Version of affected browser(s),operating system(s), npm, node and ngrx:

Other information:

[brandonroberts]

The first option seems reasonable to me. Is this error specific to closure compiler and how can we reproduce it?

[alex-okrushko]

@brandonroberts thanks for a quick reply.

I don't think it's about closure compiler. It's failing during "Compiling Angular templates (ngc)" in the project that is using ngrx v4.

Also, someone already discovered this exact issue (#518) which was also happening during ngc, but closed it assuming the fix was in uglify.

[brandonroberts]

@alex-okrushko is this still an issue?

[alex-okrushko]

yes it is. I've done Local Mod for now to get it into Google.
I can probably change it here as well sometime next week.