Spencer Feng spencerfeng

Full stack developer in Sydney

spencerfeng / functionToTest_correct.spec.js

Created December 13, 2023 11:32

For tutorial: Mastering the Art of Mocking ES Modules in Jest

	import { jest } from "@jest/globals"

	let mockedDependencyValue

	jest.unstable_mockModule("./dependency.js", () => ({
	dependency: () => mockedDependencyValue
	}));

	describe("functionToTest", () => {
	afterEach(() => {

spencerfeng / functionToTest_wrong.spec.js

Created December 13, 2023 11:17

For tutorial: Mastering the Art of Mocking ES Modules in Jest

	import { jest } from "@jest/globals"
	import * as Dependency from "./dependency.js"
	import { functionToTest } from "./functionToTest.js"

	describe("functionToTest", () => {
	afterEach(() => {
	jest.restoreAllMocks()
	})

	it("should return the correct value 1", () => {

spencerfeng / dependency.js

Created December 13, 2023 11:05

For tutorial: Mastering the Art of Mocking ES Modules in Jest

export const dependency = () => "the real dependency"

spencerfeng / handleFetchedMessage.spec.js

Created July 1, 2023 03:48

For tutorial: Testing JavaScript Code with Timeouts and Promises

	import { jest } from '@jest/globals';
	import * as FetchUtils from "../fetchMessage.js";
	import { handleFetchedMessage } from "../handleFetchedMessage.js";

	describe("handleFetchedMessage", () => {
	beforeEach(() => {
	// 1
	jest.useFakeTimers()
	})

spencerfeng / fetchMessage.js

Created July 1, 2023 03:30

For tutorial: Testing JavaScript Code with Timeouts and Promises

	export const fetchMessage = () => {
	const messages = ["Message 1", "Message 2", "Message 3"]
	const randomIndex = Math.floor(Math.random() * messages.length);

	return new Promise(resolve => {
	setTimeout(() => {
	resolve(messages[randomIndex])
	}, 2000)
	})
	}

spencerfeng / abortableSearchItems_after.ts

Created July 25, 2022 12:16

For tutorial: Create an abortable API using AbortController and AbortSignal

	const abortableSearchItems = (
	searchString: string,
	signal: AbortSignal
	): Promise<Item[]> => {
	if (signal.aborted) {
	return Promise.reject(new Error("searchAborted"));
	}

	return new Promise((resolve, reject) => {
	const abortSearchHandler = () => {

spencerfeng / searchItems.ts

Last active July 25, 2022 12:17

For tutorial: Create an abortable API using AbortController and AbortSignal

	// This is a redux action creator
	const searchItems =
	(searchString: string, signal: AbortSignal) => async (dispatch) => {
	dispatch(searchStarted());

	try {
	const items = await abortableSearchItems(searchString, signal);
	dispatch(searchSucceeded(items));
	} catch (error) {
	if ((error as any).message === 'searchAborted') {

spencerfeng / abortableSearchItems_before.ts

Last active July 25, 2022 11:49

For tutorial: Create an abortable API using AbortController and AbortSignal

	const abortSearchHandler = () => {
	throw new Error('searchAborted');
	};

	const abortableSearchItems = (
	searchString: string,
	signal: AbortSignal
	): Promise<Item[]> => {
	if (signal.aborted) {
	throw new Error('searchAborted');

spencerfeng / sudo_test_for_edward.js

Created June 18, 2022 22:04

Sudo Test For Edward

	const mockedRequest = jest.fn()

	const callback1 = mockedRequest.mock.calls[0][1]
	const callback2 = mockedRequest.mock.calls[1][1]
	const callback3 = mockedRequest.mock.calls[2][1]

	it('should return and send error if count is 3', () => {
	const mockedSend = jest.fn()
	const mockedRes = {
	send: mockedSend,

spencerfeng / dev-deploy.yml

Created April 30, 2022 11:59

For tutorial: Create a serverless service to extract the HTML of a web page and store it in an S3 bucket using Serverless Framework