Utility function to convert everything to optional

Question

Many times I find myself passing in as an arg a certain Shape type but where each key is optional, only at least one is required.

For example:

type Shape = {
    +isFetching: boolean,
    +errorFetching: null | string
}

type ShapeOpt = {
    isFetching?: boolean,
    errorFetching?: boolean
}


function set(data: ShapeOpt) {
    for (const key in data) {
        global[key] = data[key];
    }
}

Is there a utility function to convert from Shape to ShapeOpt?

Answer 1

There is a $Shape<Type> helper for generating an object type where each key is optional. But I don't know of a way to say that at least one item is required automatically.