repos / starfx

supervisor.test.ts

 1import { take } from "../action.js";
 2import { API_ACTION_PREFIX } from "../action.js";
 3import {
 4  type Operation,
 5  call,
 6  run,
 7  spawn,
 8  supervise,
 9  superviseBackoff,
10} from "../index.js";
11import { describe, expect, test } from "../test.js";
12import type { ActionWithPayload } from "../types.js";
13
14describe("superviseBackoff", () => {
15  test("should increase number exponentially", () => {
16    const actual: number[] = [];
17    for (let i = 1; i < 15; i += 1) {
18      actual.push(superviseBackoff(i));
19    }
20    expect(actual).toEqual([
21      20, 40, 80, 160, 320, 640, 1280, 2560, 5120, 10240, -1, -1, -1, -1,
22    ]);
23  });
24});
25
26type LogAction = ActionWithPayload<{ message: string }>;
27
28test("should recover with backoff pressure", async () => {
29  const err = console.error;
30  console.error = () => {};
31
32  const actions: LogAction[] = [];
33  const backoff = (attempt: number) => {
34    if (attempt === 4) return -1;
35    return attempt;
36  };
37
38  await run(function* () {
39    function* op(): Operation<void> {
40      throw new Error("boom!");
41    }
42    yield* spawn(function* () {
43      while (true) {
44        const action = yield* take<LogAction["payload"]>("*");
45        actions.push(action);
46      }
47    });
48    yield* call(supervise(op, backoff));
49  });
50
51  expect(actions.length).toEqual(3);
52  expect(actions[0].type).toEqual(`${API_ACTION_PREFIX}supervise`);
53  expect(actions[0].meta).toEqual(
54    "Exception caught, waiting 1ms before restarting operation",
55  );
56  expect(actions[1].type).toEqual(`${API_ACTION_PREFIX}supervise`);
57  expect(actions[1].meta).toEqual(
58    "Exception caught, waiting 2ms before restarting operation",
59  );
60  expect(actions[2].type).toEqual(`${API_ACTION_PREFIX}supervise`);
61  expect(actions[2].meta).toEqual(
62    "Exception caught, waiting 3ms before restarting operation",
63  );
64
65  console.error = err;
66});