// Copyright 2018-2024 the Deno authors. All rights reserved. MIT license.
import type { Range } from "./types.ts";
import { isComparator } from "./_is_comparator.ts";

/**
 * Does a deep check on the object to determine if its a valid range.
 *
 * Objects with extra fields are still considered valid if they have at
 * least the correct fields.
 *
 * Adds a type assertion if true.
 * @param value The value to check if its a valid Range
 * @returns True if its a valid Range otherwise false.
 */
export function isRange(value: unknown): value is Range {
  return Array.isArray(value) &&
    value.every((r) => Array.isArray(r) && r.every((c) => isComparator(c)));
}