Discussion on: Working with React context providers in Typescript

export type ProviderType = Authentication;
export type ContextType = ProviderType | undefined;

...

/* assert type */
function isProviderType(value: ContextType): value is ProviderType {
    return value !== undefined;
}

export function userProvider() {
    const value = React.useContext<ContextType>(ProviderContext);
    if (!isProviderType(value)) throw new Error("The component using the ...");
    return value;
}