rsxjs/__tests__/unit/test-blocking-lists.js

Resilience Extensions for JS.

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

import { v4 as uuid } from "uuid";

import { test } from "../helpers";
import { MemoryStore, delay } from "../../dist";

function createTest(ds, upushDir, upopDir, expected, wait = 0, only = false) {
  const pushDir = upushDir.toLowerCase();
  const popDir = upopDir.toLowerCase();
  const testFn = only ? test.only : test;

  testFn(
    `should be able to block as a ${ds} (${upushDir}T${upopDir})`,
    async (t) => {
      const store = new MemoryStore();
      const listName = `testList:${uuid()}`;

      const received = [];
      let shouldRun = true;
      const p = new Promise(async (resolve) => {
        await delay(wait);

        while (shouldRun) {
          const elm = await store[`b${popDir}pop`](listName, 5);
          if (elm) {
            received.push(elm);
          }
        }

        resolve();
      });

      // starts off empty
      await 1;
      t.is(received.length, 0, "Should start as an empty list");

      // push some stuff in
      await store[`${pushDir}push`](listName, "a");
      await store[`${pushDir}push`](listName, "b");
      await store[`${pushDir}push`](listName, "c");
      await store[`${pushDir}push`](listName, "d");

      // should show up in FIFO order
      while (received.length < 4) {
        await delay(5);
      }
      t.deepEqual(received, expected, `Should operate as a ${ds}`);

      // cleanup
      shouldRun = false;
      await p;
    }
  );
}

// with the consumer consuming as fast as the publisher publishes,
// it will always feel like a queue - stacks will jus\

createTest("queue", "L", "R", ["a", "b", "c", "d"]);
createTest("queue", "R", "L", ["a", "b", "c", "d"]);

// slowing it down shows the real effects of direction
createTest("queue (slow)", "L", "R", ["a", "b", "c", "d"], 1000);
createTest("queue (slow)", "R", "L", ["a", "b", "c", "d"], 1000);
createTest("stack (slow)", "L", "L", ["d", "c", "b", "a"], 1000);
createTest("stack (slow)", "R", "R", ["d", "c", "b", "a"], 1000);