Generic Type Inference Bug?

[evanbb]

TypeScript Version: 2.1.6

Code

declare module 'module' {
  interface result<T> {
    item: T
  }

  export interface resulter {
    <T extends keyof validKeys>(): result<T>
  }

  export interface validKeys {
    validKey: string
  }

  export interface results {
    [key: string]: resulter
  }
}

import { results } from 'module';

const d: results = {
  something: () => ({
    item: 'invalidKey'
  })
};

Expected behavior:
Valid values for 'item' property on result would be restricted to keys of validKeys.

Actual behavior:
Inspecting the error if the 'item' property is removed from the result confirms that the result object is typed as result.

[krryan]

Related to #13995

[mhegazy]

Not sure i understand what the use of a generic signature here is meant to enforce. but either ways, the function API says it can be called with any T, and it will somehow return you a result of the same T passed..

d.something<"validKey">();  // result<"validKey">
d.something<"anotherValidKey">();  // result<"anotherValidKey">

[typescript-bot]

Automatically closing this issue for housekeeping purposes. The issue labels indicate that it is unactionable at the moment or has already been addressed.