Khaitan

Khaitan

1625648087

React Testing Library Tutorial #4 - Structure of Tests

React Testing Library Tutorial #4 - Structure of Tests

🐱‍💻 Access the course files on GitHub:
https://github.com/harblaith7/React-Testing-Library-Net-Ninja

🐱‍👤 Get access to extra premium courses on Net Ninja Pro:
https://netninja.dev

🐱‍💻 Full React Course:
https://www.youtube.com/watch?v=j942wKiXFu8&list=PL4cUxeGkcC9gZD-Tvwfod2gaISzfRiP9d

🐱‍💻 Social Links:
Facebook - https://www.facebook.com/thenetninjauk
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#react #testing

React Testing Library Tutorial #4 - Structure of Tests
Autumn  Blick

Autumn Blick

1598839687

How native is React Native? | React Native vs Native App Development

If you are undertaking a mobile app development for your start-up or enterprise, you are likely wondering whether to use React Native. As a popular development framework, React Native helps you to develop near-native mobile apps. However, you are probably also wondering how close you can get to a native app by using React Native. How native is React Native?

In the article, we discuss the similarities between native mobile development and development using React Native. We also touch upon where they differ and how to bridge the gaps. Read on.

A brief introduction to React Native

Let’s briefly set the context first. We will briefly touch upon what React Native is and how it differs from earlier hybrid frameworks.

React Native is a popular JavaScript framework that Facebook has created. You can use this open-source framework to code natively rendering Android and iOS mobile apps. You can use it to develop web apps too.

Facebook has developed React Native based on React, its JavaScript library. The first release of React Native came in March 2015. At the time of writing this article, the latest stable release of React Native is 0.62.0, and it was released in March 2020.

Although relatively new, React Native has acquired a high degree of popularity. The “Stack Overflow Developer Survey 2019” report identifies it as the 8th most loved framework. Facebook, Walmart, and Bloomberg are some of the top companies that use React Native.

The popularity of React Native comes from its advantages. Some of its advantages are as follows:

  • Performance: It delivers optimal performance.
  • Cross-platform development: You can develop both Android and iOS apps with it. The reuse of code expedites development and reduces costs.
  • UI design: React Native enables you to design simple and responsive UI for your mobile app.
  • 3rd party plugins: This framework supports 3rd party plugins.
  • Developer community: A vibrant community of developers support React Native.

Why React Native is fundamentally different from earlier hybrid frameworks

Are you wondering whether React Native is just another of those hybrid frameworks like Ionic or Cordova? It’s not! React Native is fundamentally different from these earlier hybrid frameworks.

React Native is very close to native. Consider the following aspects as described on the React Native website:

  • Access to many native platforms features: The primitives of React Native render to native platform UI. This means that your React Native app will use many native platform APIs as native apps would do.
  • Near-native user experience: React Native provides several native components, and these are platform agnostic.
  • The ease of accessing native APIs: React Native uses a declarative UI paradigm. This enables React Native to interact easily with native platform APIs since React Native wraps existing native code.

Due to these factors, React Native offers many more advantages compared to those earlier hybrid frameworks. We now review them.

#android app #frontend #ios app #mobile app development #benefits of react native #is react native good for mobile app development #native vs #pros and cons of react native #react mobile development #react native development #react native experience #react native framework #react native ios vs android #react native pros and cons #react native vs android #react native vs native #react native vs native performance #react vs native #why react native #why use react native

How native is React Native? | React Native vs Native App Development
Dejah  Reinger

Dejah Reinger

1599859380

How to Do API Testing?

Nowadays API testing is an integral part of testing. There are a lot of tools like postman, insomnia, etc. There are many articles that ask what is API, What is API testing, but the problem is How to do API testing? What I need to validate.

Note: In this article, I am going to use postman assertions for all the examples since it is the most popular tool. But this article is not intended only for the postman tool.

Let’s directly jump to the topic.

Let’s consider you have an API endpoint example http://dzone.com/getuserDetails/{{username}} when you send the get request to that URL it returns the JSON response.

My API endpoint is http://dzone.com/getuserDetails/{{username}}

The response is in JSON format like below

JSON

{
  "jobTitle": "string",
  "userid": "string",
  "phoneNumber": "string",
  "password": "string",
  "email": "[email protected]",
  "firstName": "string",
  "lastName": "string",
  "userName": "string",
  "country": "string",
  "region": "string",
  "city": "string",
  "department": "string",
  "userType": 0
}

In the JSON we can see there are properties and associated values.

Now, For example, if we need details of the user with the username ‘ganeshhegde’ we need to send a **GET **request to **http://dzone.com/getuserDetails/ganeshhegde **

dzone.com

Now there are two scenarios.

1. Valid Usecase: User is available in the database and it returns user details with status code 200

2. Invalid Usecase: User is Unavailable/Invalid user in this case it returns status with code 404 with not found message.

#tutorial #performance #api #test automation #api testing #testing and qa #application programming interface #testing as a service #testing tutorial #api test

How to Do API Testing?
Mikel  Okuneva

Mikel Okuneva

1596793726

Where To Learn Test Programming — July 2020 Edition

What do you do when you have lots of free time on your hands? Why not learn test programming strategies and approaches?

When you’re looking for places to learn test programming, Test Automation University has you covered. From API testing through visual validation, you can hone your skills and learn new approaches on TAU.

We introduced five new TAU courses from April through June, and each of them can help you expand your knowledge, learn a new approach, and improve your craft as a test automation engineer. They are:

These courses add to the other three courses we introduced in January through March 2020:

  • IntelliJ for Test Automation Engineers (3 hrs 41 min)
  • Cucumber with JavaScript (1 hr 22 min)
  • Python Programming (2 hrs)

Each of these courses can give you a new set of skills.

Let’s look at each in a little detail.

Mobile Automation With Appium in JavaScript

Orane Findley teaches Mobile Automation with Appium in JavaScript. Orane walks through all the basics of Appium, starting with what it is and where it runs.

javascript

“Appium is an open-source tool for automating native, web, and hybrid applications on different platforms.”

In the introduction, Orane describes the course parts:

  • Setup and Dependencies — installing Appium and setting up your first project
  • Working with elements by finding them, sending values, clicking, and submitting
  • Creating sessions, changing screen orientations, and taking screenshots
  • Timing, including TimeOuts and Implicit Waits
  • Collecting attributes and data from an element
  • Selecting and using element states
  • Reviewing everything to make it all make sense

The first chapter, broken into five parts, gets your system ready for the rest of the course. You’ll download and install a Java Developer Kit, a stable version of Node.js, Android Studio and Emulator (for a mobile device emulator), Visual Studio Code for an IDE, Appium Server, and a sample Appium Android Package Kit. If you get into trouble, you can use the Test Automation University Slack channel to get help from Orane. Each subchapter contains the links to get to the proper software. Finally, Orane has you customize your configuration for the course project.

Chapter 2 deals with elements and screen interactions for your app. You can find elements on the page, interact with those elements, and scroll the page to make other elements visible. Orane breaks the chapter into three distinct subchapters so you can become competent with each part of finding, scrolling, and interacting with the app. The quiz comes at the end of the third subchapter.

The remaining chapters each deal with specific bullets listed above: sessions and screen capture, timing, element attributes, and using element states. The final summary chapter ensures you have internalized the key takeaways from the course. Each of these chapters includes its quiz.

When you complete this course successfully, you will have both a certificate of completion and the code infrastructure available on your system to start testing mobile apps using Appium.

Selenium WebDriver With Python

Andrew Knight, who blogs as The Automation Panda, teaches the course on Selenium WebDriver with Python. As Andrew points out, Python has become a popular language for test automation. If you don’t know Python at all, he points you to Jess Ingrassellino’s great course, Python for Test Programming, also on Test Automation University.

Se

In the first chapter, Andrew has you write your first test. Not in Python, but Gherkin. If you have never used Gherkin syntax, it helps you structure your tests in pseudocode that you can translate into any language of your choice. Andrew points out that it’s important to write your test steps before you write test code — and Gherkin makes this process straightforward.

first test case

The second chapter goes through setting up a pytest, the test framework Andrew uses. He assumes you already have Python 3.8 installed. Depending on your machine, you may need to do some work (Macs come with Python 2.7.16 installed, which is old and won’t work. Andrew also goes through the pip package manager to install pipenv. He gives you a GitHub link to his test code for the project. And, finally, he creates a test using the Gherkin codes as comments to show you how a test runs in pytest.

In the third chapter, you set up Selenium Webdriver to work with specific browsers, then create your test fixture in the pytest. Andrew reminds you to download the appropriate browser driver for the browser you want to test — for example, chromedriver to drive Chrome and geckodriver to drive Firefox. Once you use pipenv to install Selenium, you begin your test fixture. One thing to remember is to call an explicit quit for your webdriver after a test.

Chapter 4 goes through page objects, and how you abstract page object details to simplify your test structure. Chapter 5 goes through element locator structures and how to use these in Python. And, in Chapter 6, Andrew goes through some common webdriver calls and how to use them in your tests. These first six chapters cover the basics of testing with Python and Selenium.

Now that you have the basics down, the final three chapters review some advanced ideas: testing with multiple browsers, handling race conditions, and running your tests in parallel. This course gives you specific skills around Python and Selenium on top of what you can get from the Python for Test Programming course.

#tutorial #performance #testing #automation #test automation #automated testing #visual testing #visual testing best practices #testing tutorial

Where To Learn Test Programming — July 2020 Edition
Chumarat Pat

Chumarat Pat

1599639298

Interaction Testing with React Testing Library

Testing is complicated. I’ve certainly never been good at it. For the longest time, I’ve only been focused on basic function input-output unit tests. Why? Because they were easy — you didn’t need to render HTML, you didn’t need to query DOM elements, you didn’t need to interact with said DOM elements. But of course, React component testing is a necessity for any mature codebase. And it finally came time for me to sit down and figure it out.

That’s when I discovered React Testing Library. And suddenly, everything seemingly became much simpler. All the complexities that I’ve encountered, but not understood, that made me put off React component testing disappeared. Hopefully, the same will happen for you.

#react-testing-library #unit-testing #react #jest #interaction-testing

Interaction Testing with React Testing Library
Alayna  Rippin

Alayna Rippin

1597168800

Test Driven Development (TDD) with React Testing Library & Mock Service Worker

Let’s step up our testing game with two useful libraries that lend themselves excellently to a TDD approach.

Setting up

Whenever I want to try out something React-related, I use the library create-react-app. It gives you a ready-to-work-with basic React application with no configuration needed. Recent versions also come bundled with React Testing Library, so if you use the latest create-react-app, you can start using React Testing Library straight away. If not — install @testing-library/react and @testing-library/jest-dom in your existing React application.

I am going to implement the following functionality: a simple recipe list with a search function. It will look something like this to a user in a mobile browser:

Image for post

Image credits: Burger Photo by Robin Stickel on Unsplash, French Toast Photo by Joseph Gonzalez on Unsplash, Salmon Photo by Casey Lee on Unsplash

Starting with a failing test

I want to use a TDD approach, so let’s start with a failing test. At this point, there is no component yet, so of course whatever test we write is going to fail. But let’s start small; I want a component named ‘Recipes’ that renders the expected heading text. Here is my test for that expectation:

	import React from 'react';
	import { render, screen } from '@testing-library/react';

	test('renders the heading', () => {
	  render(<Recipes />);

	  expect(screen.getByRole('heading')).toHaveTextContent('Recipe Finder');
	});

React testing library exports a render method, which will render a component and all of its child components. It also exports a screen object, holding a number of queries we can use to select different elements in our rendered component (and its child components too). The **getByRole **query lets me select the heading element and make an assertion on its text content.

Why select the heading element by its role and not for example a CSS class? The guiding principle of React Testing Library is “The more your tests resemble the way your software is used, the more confidence they can give you.” Therefore, we want to write our tests as close as possible to how the ultimate tester — the end user — will be using the application. Users don’t see CSS classes or data attributes; they interact with text, label text and semantic elements and roles. Using queries such as getByRole also encourages us to write accessible code, since these selectors are available to everyone, including users of screen readers.

Making the test pass

Our first test fails as expected.** Recipes is not defined.** But this is the first step in TDD — a failing test. Now, let’s make it pass by writing the simplest possible component with the correct heading and then importing it in our test file. Now, let’s re-run the test. It passes!

	import React from 'react';

	const Recipes = () => {
	  return (
	    <div>
	      <h1>Recipe Finder</h1>
	    </div>
	  )
	};

	export default Recipes;

Using further queries, we can make similar expectations for the input element and the “Find” button. The button also has a role, but for the input field, I will use the getByPlaceholderText query, since that is probably the closest query to how the user would find it on the page.

Start with a failing test…

	import React from 'react';
	import { render, screen } from '@testing-library/react';
	import Recipes from './Recipes';

	test('renders the heading, input field and button', () => {
	  render(<Recipes />);

	  expect(screen.getByRole('heading')).toHaveTextContent('Recipe Finder');
	  expect(screen.getByPlaceholderText('Enter an ingredient to find recipes...'))
	    .toBeInTheDocument();
	  expect(screen.getByRole('button')).toHaveTextContent('Find');
	});

… and implement the changes necessary to make it pass:

	import React from 'react';

	const Recipes = () => {
	  return (
	    <div>
	      <h1>Recipe Finder</h1>
	      <form>
	        <input 
	          type="text" 
	          name="ingredient"
	          placeholder="Enter an ingredient to find recipes..." 
	        />
	        <button type="submit">Find</button>
	      </form>
	    </div>
	  )
	};

	export default Recipes;

This way, we know what we expect from our code and more importantly — we will know if we break any functionality if the previously passing tests suddenly fail.

An important step in TDD is the refactor step, where we improve our code to for example make it easier to read, become more efficient and remove any duplication. The test should still pass after we refactor.

Setting up our mocks

When the application first renders, I want to display a list of all my recipes, just like in the visual design above. This requires some kind of communication with an API. We are going to use Mock Service Worker to mock the HTTP-requests, so that we can control the response data. Install Mock Service Worker with npm like this:

npm install msw --save-dev

With Mock Service Worker, we are not mocking a specific module (unlike if we were to use Jest.mock), which means that it makes no difference if I use fetch or a third-party library such as axios to get the data. This makes it incredibly flexible. Let’s add the following imports to our test file:

import { rest } from 'msw';
import { setupServer } from 'msw/node';

Here is how I set up mocking a call to the recipe list endpoint:

	import React from 'react';
	import { render, screen } from '@testing-library/react';
	import Recipes from './Recipes';
	import { rest } from 'msw';
	import { setupServer } from 'msw/node';

	const allRecipes = [
	  { id: 1, title: 'Burger' }, 
	  { id: 2, title: 'French toast' }, 
	  { id: 3, title: 'Salmon' }
	];

	const server = setupServer(
	  rest.get('/api/recipes', (req, res, ctx) => {
	    return res(ctx.json({ recipes: allRecipes }));
	  })
	);

	beforeAll(() => server.listen());

afterAll(() => server.close());

If you have worked with NodeJS and Express, the syntax looks very familiar. GET requests to ‘/api/recipes’ will respond with JSON containing the allRecipes array, just like a real API would. These two lines make sure the server starts listening (intercepting) before the tests run and closes its connection when the tests in this file have finished running:

beforeAll(() => server.listen());
afterAll(() => server.close());

#tdd #react-testing-library #react #test-driven-development #testing

Test Driven Development (TDD) with React Testing Library & Mock Service Worker