Typescript not reported about extra key in returned object in function

[ctr52]

TypeScript Version: 2.9

Search Terms: excess key in returned object in function
Code

interface ITestFunctionReturns {
    key1: number,
    key2: string,
}
type ITestFunction = () => ITestFunctionReturns

const testFunction: ITestFunction = () => ({
    asd: true,
    key1: 123,
    key2: 'str',
})

Expected behavior: typescript will report about extra key in the object

Actual behavior: I must point the interface in yet another place, without this typescript does not report an error

interface ITestFunctionReturns {
    key1: number,
    key2: string,
}
type ITestFunction = () => ITestFunctionReturns

const testFunction: ITestFunction = (): ITestFunctionReturns => ({
    asd: true,
    key1: 123,
    key2: 'str',
})

[OYangXiao]

I‘ve also encountered this problem, this is what my code looks like

interface ITest {
  [name: string]: () => { one1: 1 };
}

const TestImpl: ITest = {
  test: function() {
    return { one: 1, two: 2 };
  }
};

[RyanCavanaugh]

Duplicate #12632

[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.