@quyse/client-zip/test/crc32.test.ts

A tiny and fast client-side streaming ZIP generator

import { assertEquals } from "https://deno.land/std@0.132.0/testing/asserts.ts"
import { crc32, CRC_TABLE } from "../src/crc32.ts"

const table = await Deno.readFile("./test/table.array")

Deno.test("the CRC32 module precomputes CRCs for each byte using the polynomial 0xEDB88320", () => {
  const actual = new Uint8Array(CRC_TABLE.buffer)
  const expected = table.slice(0, 0x400)
  assertEquals(actual, expected)
})

Deno.test("the CRC32 for an empty file", () => {
  assertEquals(crc32(new Uint8Array(0), 0), 0)
})

Deno.test("the CRC32 for short files", () => {
  assertEquals(crc32(new TextEncoder().encode("Hello world!"), 0), 0x1b851995)
  assertEquals(crc32(new TextEncoder().encode("WebAssmebly is fun. Also 10x faster than JavaScript for this."), 0), 0x8a89a52a)
  assertEquals(crc32(new Uint8Array(table), 0), 0x1a76768f)
})

Deno.test("the CRC32 for files larger than 64kB", () => {
  const zipSpec = Deno.readFileSync("./test/APPNOTE.TXT")
  assertEquals(crc32(new Uint8Array(zipSpec), 0), 0xbb3afe3f)
})