Query data defined inside .map closure

[dhulme]

If I have the following code:

type Query = { data?: number[]; }
const x = {} as Query;
const y = {} as Query;

x.data && y.data?.map(item => {
    const xItem = x.data.find(_ => _);
})

Typescript throws an error on x.data, because x.data is possibly undefined. This is because it is inside a closure. But the same code with 2 actual react queries does not throw a type error. Does anyone know why this is?