buffer-equal.assert.ts

import { AssertionError } from "../../assertion-error.js";
import { desc } from "../../describe/describe.js";
import { bufferEqualTo } from "./buffer-equal.match.js";

import type { TypedArray } from "../type-typed-array/type-typed-array.type.js";

/**
 * Assert that two buffers (TypedArrays) are equal, comparing element by element.
 * Supports all TypedArray types: Uint8Array, Int8Array, Uint16Array, Int16Array,
 * Uint32Array, Int32Array, Float32Array, Float64Array, BigInt64Array, BigUint64Array.
 * @example
 * ```ts
 * import { assertBufferEqual } from "@kensio/smartass";
 *
 * const value: unknown = Buffer.from("ok");
 *
 * assertBufferEqual(value, Buffer.from("ok"));
 *
 * // value is now narrowed to Buffer
 * ```
 */
export function assertBufferEqual<T extends TypedArray>(
  actual: unknown,
  expected: T,
  message?: string,
): asserts actual is T {
  if (!bufferEqualTo(expected).isMatch(actual)) {
    throw new AssertionError(
      message ?? `Expected ${desc(actual)} to equal ${desc(expected)}.`,
      actual,
      expected,
    );
  }
}