I want to have a type which looks like:

type MyProps = {
  context: string;
  // other props
}

Except I want the context to have been generated from a specific function / or at least have a specific type (though it’s really a string). For example:

function getContext(props: ContextProps) {
 const { a, b, c } = props;

 return `${a} [ ${b} / ${c} ]`;
}

const myProps = {
  context: getContext({ a: "test", b: "ABC", c: "123" }),
};

But setting context to any string should fail:

const myProps = {
  context: "some other string",
};

I’ve tried this, but it allows a plain string to be set to context:

function getContext(props: ContextProps) {
 const { a, b, c } = props;

 return `${a} [ ${b} / ${c} ]` as ContextString;
}

type ContextString = string;

// or 

interface ContextString extends String { }

Is it possible to enforce this?