isNonNullable utility, allows you to simply write .filter(isNonNullable) on an array to exclude null/undefined and get the correct array type as a result.

isNonNullable.ts

/**
 * Type guard to check if a value is non-nullable.
 *
 * This is useful for filtering out null and undefined values from arrays.
 * Unlike Boolean this will only filter out null and undefined values and the type of the value will be narrowed accordingly.
 *
 * @param value The value to check.
 * @returns True if the value is not null or undefined, false otherwise.
 *
 * @example If condition
 * ```ts
 * if (isNonNullable(value)) {
 *   // Value is now narrowed to exclude null and undefined
 * }
 * ```
 *
 * @example Filtering an array
 * ```ts
 * const values = [1, null, 2, undefined, 3];
 * const nonNullableValues = values.filter(isNonNullable);
 * // nonNullableValues is now [1, 2, 3]
 * ```
 */
export function isNonNullable<T>(value: T): value is NonNullable<T> {
	return value != null;
}