Inference issue in literal objects

[pauliusrum]

I have noticed a problem with type inference of literal objects. Given example where alignment property should be of type "left" but it is string instead and it is not accepted by the given printText function when it is passed as a variable params but work when it is specified directly at the function invocation. Does this work as intended or is it a bug?

Tested with Typescript 2.8.

type Alignment = "left" | "right" | "center"

const params = {
    alignment: "left"
}

function printText(text: string, options: { alignment: Alignment }) {
    console.log(text)
}

printText("Test", params) // Compile error
printText("Test", { ...params }) // Compile error
printText("Test", {alignment: "left"}) // Correct

[MartinJohns]

Working as intended: #20271

A sensible rule (perhaps enforced with tslint?) is that when you assign a created object literal to a variable it should always be typed. Only then the "object literal may only specify known properties" check will work too, informing you about obsolete properties when you removed it from the type but not in the code.