rsxjs/__tests__/integration/mutex/test-mutex.js

Resilience Extensions for JS.

/**
 * @file tests/mutex/test-mutex.js
 * @copyright 2018-present Karim Alibhai. All rights reserved.
 */

import { test } from "../../helpers";
import { delay } from "bluebird";

import { Mutex } from "../../../";

const DELAY = 100;

function createTest(method, fn) {
  return async (t) => {
    const LEN = 30;

    const frames = [];
    const lockedFn = Mutex[method](fn);

    // concurrently start 30 of these, should
    // take 3s to run and all frames should be
    // 100ms+ apart
    const start = Date.now();
    await Promise.all([...new Array(LEN).keys()].map(() => lockedFn(frames)));
    const end = Date.now();

    t.true(end - start >= 3e3, "should take at least 3s to run");
    t.is(frames.length, LEN, `should have ${LEN} frames`);

    for (let i = 1; i < frames.length; ++i) {
      t.true(
        frames[i] - frames[i - 1] >= DELAY,
        `should have at least ${DELAY}ms between frames`
      );
    }
  };
}

test(
  "Mutex#fromAsync",
  createTest("fromAsync", async function (frames) {
    await delay(DELAY + 1);
    frames.push(Date.now());
  })
);

test(
  "Mutex#fromGenerator",
  createTest("fromGenerator", function* (frames) {
    const r = Math.random();
    if (r !== (yield r) || r !== (yield Promise.resolve(r))) {
      throw new Error(`Mutex.fromGenerator() should return values in yields`);
    }

    yield delay(DELAY + 1);
    frames.push(Date.now());
  })
);

test("Mutex#lock", async (t) => {
  const LEN = 30;

  const frames = [];
  async function lockedFn() {
    const m = await Mutex.lock({ name: "test" });
    await delay(DELAY + 1);
    frames.push(Date.now());
    await m.unlock();
  }

  // concurrently start 30 of these, should
  // take 3s to run and all frames should be
  // 100ms+ apart
  const start = Date.now();
  await Promise.all([...new Array(LEN).keys()].map(() => lockedFn(frames)));
  const end = Date.now();

  t.true(end - start >= 3e3, "should take at least 3s to run");
  t.is(frames.length, LEN, `should have ${LEN} frames`);

  for (let i = 1; i < frames.length; ++i) {
    t.true(
      frames[i] - frames[i - 1] >= DELAY,
      `should have at least ${DELAY}ms between frames`
    );
  }
});