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Nested object type inference #25295

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Jomik opened this issue Jun 28, 2018 · 3 comments
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Nested object type inference #25295

Jomik opened this issue Jun 28, 2018 · 3 comments
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@Jomik
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Jomik commented Jun 28, 2018

TypeScript Version: 3.0.0-dev.20180628

Search Terms: infer nested type object

Code

class Foo<A> {
  private a: A;
}

class ObjectFoo<A> extends Foo<A> {
  constructor(private b: { [k in keyof A]: Foo<A[k]> }) {
    super();
  }
}

const a = new ObjectFoo({ b: new Foo<string>() });
const obj = new ObjectFoo({ a });

Expected behavior:
Expect obj to have type { a: { b: string } }

Actual behavior:
obj has type { a: { b: any } }

Playground Link:
playground

Related Issues:

@RyanCavanaugh
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This is just a bug in the typeToString code; the actual type of b is string

Duplicate of #23897

@Jomik
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Jomik commented Jun 28, 2018

@RyanCavanaugh so the actual type is inferred for multiple layers of nested objects? :)
Thank you, I will follow that issue, feel free to close this!

@RyanCavanaugh
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Yep, you can try in the Playground - the properties of string will show up on obj.a.a.b (once you remove the private modifier)

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