@rezi-ui/testkit

Test utilities and fixtures for Rezi applications and package-level tests.

What it provides

• Fixtures for protocol and drawlist tests (golden byte blobs)
• Golden helpers (assertBytesEqual, hexdump) for stable diffs
• Deterministic fuzz helpers (runFuzz, fuzzTest, createRng) for seeded fuzz-lite and failure-injection tests
• Snapshot helper (matchesSnapshot) for text-frame regression tests
• Convenience re-exports of Node’s node:test and node:assert APIs (Node-only)

Typical usage

import { assert, describe, matchesSnapshot, readFixture, test } from "@rezi-ui/testkit";

describe("zrev parser", () => {
  test("accepts valid v1 fixture", async () => {
    const bytes = await readFixture("zrev-v1/valid/key.bin");
    assert.ok(bytes.byteLength > 0);
  });
});

test("snapshot rendered frame text", () => {
  matchesSnapshot("hello\nworld", "example-frame");
});

Seeded fuzz tests should use runFuzz() or fuzzTest() so failures include the suite seed, iteration, derived case seed, and any notes needed to reproduce the generated input. Seeds must be unsigned 32-bit integers.

import { assert, randomInt, runFuzz, test } from "@rezi-ui/testkit";

test("parser fuzz-lite", async () => {
  await runFuzz({ seed: 0x5a524556, iterations: 1000, label: "parser" }, (ctx) => {
    const bytes = ctx.rng.bytes(randomInt(ctx.rng, 0, 256));
    ctx.note(`len=${bytes.byteLength}`);
    assert.equal(typeof bytes.byteLength, "number");
  });
});

Snapshot files are stored at <test-dir>/__snapshots__/<name>.txt. Set UPDATE_SNAPSHOTS=1 to regenerate snapshots intentionally.

If you are writing tests outside this repo, prefer installing a released version that matches your @rezi-ui/core version.