gristlabs_grist-core/test/common/Interval.ts

142 lines
4.7 KiB
TypeScript
Raw Normal View History

import {Interval} from 'app/common/Interval';
import {delay} from 'bluebird';
import {assert} from 'chai';
import * as sinon from 'sinon';
describe('Interval', function() {
const delayMs = 100;
const varianceMs = 50;
const promiseDelayMs = 200;
const delayBufferMs = 20;
let interval: Interval;
let spy: sinon.SinonSpy;
beforeEach(() => {
spy = sinon.spy();
});
afterEach(async () => {
if (interval) {
await interval.disableAndFinish();
}
});
it('is not enabled by default', async function() {
interval = new Interval(spy, {delayMs}, {onError: () => { /* do nothing */ }});
assert.equal(spy.callCount, 0);
await delay(delayMs + delayBufferMs);
assert.equal(spy.callCount, 0);
});
it('can be disabled', async function() {
interval = new Interval(spy, {delayMs}, {onError: () => { /* do nothing */ }});
interval.enable();
await delay(delayMs + delayBufferMs);
assert.equal(spy.callCount, 1);
// Disable the interval, and check that the calls stop.
interval.disable();
await delay(delayMs + delayBufferMs);
assert.equal(spy.callCount, 1);
// Enable the interval again, and check that the calls resume.
interval.enable();
await delay(delayMs + delayBufferMs);
assert.equal(spy.callCount, 2);
spy.resetHistory();
});
it('calls onError if callback throws an error', async function() {
const callback = () => { throw new Error('Something bad happened.'); };
const onErrorSpy = sinon.spy();
interval = new Interval(callback, {delayMs}, {onError: onErrorSpy});
interval.enable();
// Check that onError is called when the callback throws.
assert.equal(onErrorSpy.callCount, 0);
await delay(delayMs + delayBufferMs);
assert.equal(onErrorSpy.callCount, 1);
// Check that the interval didn't stop (since the onError spy silenced the error).
await delay(delayMs + delayBufferMs);
assert.equal(onErrorSpy.callCount, 2);
});
describe('with a fixed delay', function() {
beforeEach(() => {
interval = new Interval(spy, {delayMs}, {onError: () => { /* do nothing */ }});
interval.enable();
});
it('calls the callback on a fixed interval', async function() {
await delay(delayMs + delayBufferMs);
assert.equal(spy.callCount, 1);
await delay(delayMs + delayBufferMs);
assert.equal(spy.callCount, 2);
});
});
describe('with a randomized delay', function() {
beforeEach(() => {
interval = new Interval(spy, {delayMs, varianceMs}, {
onError: () => { /* do nothing */ }
});
interval.enable();
});
it('calls the callback on a randomized interval', async function() {
const delays: number[] = [];
for (let i = 1; i <= 10; i++) {
// Get the current delay and check that it's within the expected range.
const currentDelayMs = interval.getDelayMs();
delays.push(currentDelayMs!);
assert.isDefined(currentDelayMs);
assert.isAtMost(currentDelayMs!, delayMs + varianceMs);
assert.isAtLeast(currentDelayMs!, delayMs - varianceMs);
// Wait for the delay, and check that the spy was called.
await delay(currentDelayMs!);
assert.equal(spy.callCount, i);
}
// Check that we didn't use the same delay all 10 times.
assert.notEqual([...new Set(delays)].length, 1);
});
});
describe('with a promise-based callback', function() {
let promiseSpy: sinon.SinonSpy;
beforeEach(() => {
const promise = () => delay(promiseDelayMs);
promiseSpy = sinon.spy(promise);
interval = new Interval(promiseSpy, {delayMs}, {onError: () => { /* do nothing */ }});
interval.enable();
});
it('waits for promises to settle before scheduling the next call', async function() {
assert.equal(promiseSpy.callCount, 0);
await delay(delayMs + delayBufferMs);
assert.equal(promiseSpy.callCount, 1);
await delay(delayMs + delayBufferMs);
assert.equal(promiseSpy.callCount, 1); // Still 1, because the first promise hasn't settled yet.
await delay(delayMs + delayBufferMs);
assert.equal(promiseSpy.callCount, 1); // Promise now settled, but there's still a 100ms delay.
await delay(delayMs + delayBufferMs);
assert.equal(promiseSpy.callCount, 2); // Now we finally call the callback again.
});
it('can wait for last promise to settle when disabling', async function() {
assert.equal(promiseSpy.callCount, 0);
await delay(delayMs + delayBufferMs);
assert.equal(promiseSpy.callCount, 1);
await interval.disableAndFinish();
// Check that once disabled, no more calls are scheduled.
await delay(promiseDelayMs + delayMs + delayBufferMs);
assert.equal(promiseSpy.callCount, 1);
});
});
});