Type '{ status: string; }' is not assignable to type 'MyType'. Types of property-CodePudding

I have a .ts file and I want to use the following type definition:

type MyType = {
    status: "ACTIVE" | "INACTIVE"
}

When I use this type for a variable which I directly set value, everything is good:

const myObj1: MyType = {
    status: "ACTIVE"
}

But if I use a variable to set the value I get an error:

const data = {
    status: "ACTIVE"
}
const myObj2: MyType = data

Error:

Type '{ status: string; }' is not assignable to type 'MyType'.
  Types of property 'status' are incompatible.
    Type 'string' is not assignable to type '"ACTIVE" | "INACTIVE"'.

You can try it on here

I tried different options (like this), but the problem is that my types are generated from Json Schemas and I can't edit the generated files.

CodePudding user response：

This is because status in data is infered as a string whereas MyType expects it to be either "ACTIVE" or "INACTIVE". You need just to use as const assertion

type MyType = {
    status: "ACTIVE" | "INACTIVE"
}


const myObj1: MyType = {
    status: "ACTIVE"
}


const data = {
    status: "ACTIVE"
} as const
const myObj2: MyType = data

Or you can use new satisfies keyword which is available in TS 4.9

type MyType = {
    status: "ACTIVE" | "INACTIVE"
}

const myObj1: MyType = {
    status: "ACTIVE"
}

const data = {
    status: "ACTIVE"
} satisfies MyType

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