In a TypeScript interface, I define the properties for a user object like this:
export interface User {
firstName?: string;
lastName?: string;
displayName?: string;
photoURL?: string;
email?: string;
phoneNumber?: string;
uid: string;
}
There is a variable called 'user' with type boolean | User. Now, my goal is to narrow down its type using this approach:
if (typeof user === 'User') {
//Perform operations with the User object that cannot be done with a boolean
}
However, I encounter a TypeScript error stating:
This condition will always return 'false' since the types '"string" | "number" | "bigint" | "boolean" | "symbol" | "undefined" | "object" | "function"' and '"User"' have no overlap. ts(2367)
I also attempted another method:
if (user instanceof 'User') {
//Perform operations with the User object that cannot be done with a boolean
}
Unfortunately, this results in a different TypeScript error:
The right-hand side of an 'instanceof' expression must be of type 'any' or of a type assignable to the 'Function' interface type. ts(2359)
What is the correct way to properly narrow the variable down for the User type?