Learn Ios, Jest and Serverless

Starting from a prebuilt frontend, Jason Lengstorf guides you through the creation of a "Corgi Up-boop App" that uses Netlify Functions and Hasura. You can view [the deployed final product on Netlify](https://egghead-serverless-functions.netlify.app/).

You'll set up the Netlify CLI, and configure a local development environment before writing and deploying functions with a few different use cases.

The first example function bypasses CORS restrictions to retrieve corgi data from an example third-party API.

Next, you'll configure environmental variables to securely communicate with the Unsplash API without exposing private keys to the client.

Serverless functions don't persist data by themselves, so we will use  Hasura to create a GraphQL API for tracking the number of "boops" each corgi receives.

This course is an excellent illustration of the speed of Serverless functions, and how fast you can implement functionality in your web applications.

An all-in-one workflow that combines global deployment, continuous integration, and automatic HTTPS.

netlify

Build a Corgi Up-boop Web App with Netlify Serverless Functions and Hasura

In this collection, we build a minimal flashcard application using React, primarily focusing on function components and the hooks API. To make sure we can understand and maintain existing code, there are also a few lessons toward the end that use class components so you can get familiar with the syntax. We cover important React concepts, and sprinkle in libraries that are pretty standard in the ecosystem like @reach/router, Jest, and React testing library. We start with create-react-app so we can get right into it without worrying about configuring tooling. There's [a separate course for that here](https://egghead.io/courses/modern-javascript-tooling-with-react?af=5mx0ie)

jest

Build a React App with the Hooks API

In this course we are going to work through properly setting up Enzyme with Jest to test rendered components. This includes the nitty gritty of making our testing environment work with various versions of React. After we get our environment setup ready, we’ll work through the different ways we can render a component within our test pages. With a rendered component we can now test component methods and properties to assert that they are what is intended. 

React is one of the web’s most popular frameworks for building JavaScript applications. 

If you know what you’re doing, React can drastically simplify how you build, use, and maintain code.

Whether you’re a React newbie or you’re ready for advanced techniques, you can level-up with egghead. Explore our in-depth courses, lessons, and community resources to build more powerful applications and crack open your career.

react

Test React Components with Enzyme and Jest

End-to-end testing assures you of a few things: that all the integrated pieces of an application properly function, all those pieces work together as expected, and your tests include and simulate real-user scenarios — something unit and integration tests just don't do.

This course introduces you to two great tools for E2E testing: 

* Puppeteer opens and runs applications in a Chromium browser and performs the actions it's given.
* Jest asserts that the integrated pieces work as expected and that add-on libraries like Faker and pixelmatch take our tests to the next level.

Over 9 lessons, we will create common application features and use Puppeteer and Jest to run different types of tests against them. You'll get practice using these tools to render content, mimic user activity, automate tests, and measure the overall performance of your application.

End to End Testing with Google's Puppeteer and Jest

A lot of the time, web apps are built primarily with the desktop layout in consideration, and the mobile layout suffers as a result. In this course we are going to discuss using features of user interface which are optimised for mobile devices.

We are going to discuss CSS features that make a big difference and build entire components that work great on mobile devices and browsers. We are going to take into account browser support to ensure our users are getting the experience we want them to.

More and more of our users depend on their mobile device to use our web apps. With this in mind, we are going to look at how to optimise the components we build for smaller viewports, and how to ensure our customer gets an optimised version of our web app for their device.

We are going to discuss different ways we can view, test, and debug our web app in a mobile setting so that we know what we are seeing is what our user is seeing, because sometimes a desktop browser emulating a mobile device just isn’t enough.


HTML 5 is the structure of our web pages. It is the markup that represents the DOM (document object model).

html

Optimize User Experience for Mobile Devices and Browsers

Create a serverless application and deploy it in under thirty minutes!

We'll be using Netlify, Vite, TypeScript, and React in our project. This stack synergizes extremely well for rapidly developing professional-quality applications. 

If you haven't heard of Vite, it's the French word for quick! It's also a build tool that consists of a dev-server and an extremely fast bundler. It makes for a rapid development loop.

As for the rest. Netlify makes hosting fast and easy with serverless functions and continuous deployment. React enables you to quickly create reusable components. And TypeScript helps you write cleaner code that is easier to refactor. 

So get started and learn how to use this stack in your own applications!

Create a TypeScript powered serverless React application

Best practices for building & testing redux applications have changed dramatically over time. This course aims to be a comprehensive and up-to-date resource for those seeking to confidently test their redux apps. Whether you're just getting started or want to improve on your existing testing strategy, there will be something in this course for you.

This first few lessons of this course look at how to add jest to an existing react/redux application that was built on top of [vite](https://vitejs.dev/). We cover basic functionality like using `npm test` vs `npx jest` and generating and using [code coverage](https://jestjs.io/docs/cli#--coverageboolean) to inform our testing strategy.

The next 10 or so lessons cover the specifics of unit testing the redux code in our application. We'll go over how to test reducers, selectors and thunks. As part of this we'll touch on mocking APIs and using [Redux Mock Store](https://github.com/reduxjs/redux-mock-store) as well as running actions through our applications' actual reducers to broaden our test coverage.

In the final part of this course we'll look at how we can test our redux connected react components using the various utilities that come with the [React Testing Library](https://testing-library.com/docs/react-testing-library/intro/). We'll cover simulating various kinds of user input with the [User Event Module](https://testing-library.com/docs/ecosystem-user-event), populating our redux store with test data, using [jest spies](https://jestjs.io/docs/jest-object#jestspyonobject-methodname), how to wait for asynchronous tasks to complete, and several approaches for finding & asserting that visual elements exist on the page.

This course is built on top of content that was created for the [Modern Redux with RTK and TypeScript](https://app.egghead.io/playlists/modern-redux-with-redux-toolkit-rtk-and-typescript-64f243c8) course and I highly recommend you start there if you haven't completed it already. It does expect a *basic* familiarity with react, redux and jest. TypeScript is used in these lessons, but is not a major focus and hopefully won't distract you too much if you prefer plain JavaScript.

No matter your experience level with redux and testing react applications, I'm confident your abilities will level up as you watch this course and follow along with the examples.

Thank you!

Confidently Testing Redux Applications with Jest & TypeScript

Here are all the Egghead.io lessons about testing with Jest! http://facebook.github.io/jest (https://kcd.im/egghead-jest)

Testing JavaScript with Jest

Open source framework for building truly native mobile apps with Angular, TypeScript or JavaScript.

nativescript

Objective C is a very interesting programming language which offers a lot of power as well as interesting paradigms. Let’s look at some Objective C api’s and how they translate to NativeScript. In particular, let’s learn how to wire up iOS delegates using [Filestack's FSPickerDelegate](https://github.com/filestack/FSPicker#fspickerdelegate) as an example. We will also look at handling WeakRef’s and iterating an NSArray.

Use Objective C Delegates in NativeScript for Angular iOS apps

One of the exciting benefits you have with NativeScript is the ability to write native code (Java and Objective C) directly in JavaScript/TypeScript allowing you to create a consistent high level api over top of both underlying iOS Objective C/Swift and Android Java apis. In this lesson, we will look at how to design a consistent api that taps into the appropriate native api’s on the target platforms using underlying native libraries.

Develop a consistent plugin api across your Android and iOS NativeScript app

To prepare your development environment to code against native apis such as Objective C, Swift and Java, let's learn how to [install tns-platform-declarations](https://www.npmjs.com/package/tns-platform-declarations) to provide rich intellisense support for all the native iOS and Android api’s. This lesson will cover how to modify your tsconfig.json and references.d.ts properly to ensure working with native api’s is smooth and as helpful as possible.

Prepare for native iOS and Android api intellisense with NativeScript

In this lesson we'll explore debugging our React Native application in an actual iOS device.

React Native: Debugging on an iOS Device

We will learn how to install an Objective C library distributed via a [CocoaPod](https://cocoapods.org) into our project and expose its native api to our app. Specifically, we will cover how to immediately start working with the library even when a [NativeScript](/q/nativescript) plugin does not exist for it. Take for example [Filestack](https://filestack.com), a really powerful file uploading api that provides an SDK written in [JavaScript](/q/javascript) for the web, but also offers native SDK's for iOS and Android. Let's take a look at how to code right against this [native iOS SDK](https://filestack.com/docs/sdks/ios).

Use an Objective C library in NativeScript for Angular iOS app

In this lesson we'll look at some simple ways to customize TabBarIOS, creating a scrollable tab area, and implementing custom icons in TabBarIOS.Item.

React Native: TabBarIOS Customization

Learn how to generate TypeScript declaration files for all native api’s for iOS, including any 3rd party Objective C/Swift libraries included in your project via Cocoapods or other means. This will allow you to view all the metadata for included iOS libraries to see what classes and apis are exposed to NativeScript.

Generate metadata TypeScript declarations for Objective C/Swift libraries on iOS

Building a custom NativeScript XML view component for iOS entails several interesting notes, like overriding the onLoaded method of the base NativeScript View class. Let’s look at how to properly build a custom component based on an underlying native view widget with NativeScript XML which may come from a CocoaPod. We will learn several important aspects regarding Objective C properties and methods you will need to consider. In particular, we will implement this [Objective C view component](https://github.com/Boris-Em/BEMAnalogClock)

Build a custom NativeScript view component for iOS

Swift is an exciting and intuitive programming language developed by Apple to be easier to learn than Objective C. It's syntax also more closely resembles JavaScript. Some native libraries you could work with may have been developed with Swift. Let’s look at a couple cases you could run into when trying to work with a Swift based iOS library. In particular, we will be implementing this [Swift 3.0 CocoaPod](https://cocoapods.org/pods/SimplePDF). Also learn how to write files to your app’s document folder using NativeScript’s ‘file-system’ module. 

Convert a Swift library to NativeScript for Angular iOS apps

React Native lets you build mobile apps using only JavaScript. It uses the same design as React, letting you compose a rich mobile UI from declarative components.

react-native

Learn to write components that render differently on iOS and Android, but present the same API. First, we'll use the Platform module to change behavior based on the platform. Then, we'll use the platform-specific file extensions, .ios.js and .android.js, to render platform-specific components.


Writing Platform-Specific Components for iOS and Android in React Native

Let's learn how to unit test your JavaScript with [Jest](http://facebook.github.io/jest), a JavaScript unit testing framework from Facebook. We'll install and optimize Jest for this project and see how quick and easy it is to get things going with Jest.

Test JavaScript with Jest

Jest comes pre-packaged with the ability to track code coverage for the modules you're testing, but it takes a little extra work to make it track untested files as well. Let's look at what Jest can do for you, what you have to do yourself, and how to setup code coverage thresholds so you can work to improving the code coverage numbers for your projects.

Track project code coverage with Jest

Jest is a painless JavaScript unit testing framework from Facebook. It is designed to be super easy to setup and is packed full of powerful features. In this lesson we see how easy it is to add to your TypeScript project. This will be followed by a quick example application.