export const isNull = < T >( term: T | null ): term is null => {
return term === null;
};
export const isNumber = < U >( term: number | U ): term is number => {
return typeof term === 'number';
};
export const isString = < U >( term: string | U ): term is string => {
return typeof term === 'string';
};
export const isObject = < T extends Record< string, unknown >, U >(
term: T | U
): term is NonNullable< T > => {
return ! isNull( term ) && typeof term === 'object';
};
export function objectHasProp< P extends PropertyKey >(
target: Record< string, unknown >,
property: P
): target is { [ K in P ]: unknown } {
// The `in` operator throws a `TypeError` for non-object values.
return property in target;
}
// eslint-disable-next-line @typescript-eslint/ban-types
export const isFunction = < T extends Function, U >(
term: T | U
): term is T => {
return typeof term === 'function';
};