Book Image

Learn React with TypeScript 3

By : Carl Rippon
Book Image

Learn React with TypeScript 3

By: Carl Rippon

Overview of this book

React today is one of the most preferred choices for frontend development. Using React with TypeScript enhances development experience and offers a powerful combination to develop high performing web apps. In this book, you’ll learn how to create well structured and reusable react components that are easy to read and maintain by leveraging modern web development techniques. We will start with learning core TypeScript programming concepts before moving on to building reusable React components. You'll learn how to ensure all your components are type-safe by leveraging TypeScript's capabilities, including the latest on Project references, Tuples in rest parameters, and much more. You'll then be introduced to core features of React such as React Router, managing state with Redux and applying logic in lifecycle methods. Further on, you'll discover the latest features of React such as hooks and suspense which will enable you to create powerful function-based components. You'll get to grips with GraphQL web API using Apollo client to make your app more interactive. Finally, you'll learn how to write robust unit tests for React components using Jest. By the end of the book, you'll be well versed with all you need to develop fully featured web apps with React and TypeScript.
Table of Contents (14 chapters)

Working with cached data in Apollo

We ended the last section with a bit of a mystery. Why aren't we getting the up-to-date number of stars in a repository search after we've started it? The answer is that Apollo caches the repository data after the initial search. When the same query is executed, it gets the results from its cache, rather than getting the data from the GraphQL server.

Let's double-check that this is the case:

  1. Let's go to our app and open Developer tools on the Network tab and clear any previous requests:
  1. Let's do a search. We'll see a couple of requests to the GitHub GraphQL server:
  1. Under the Developer tools, Network tab, let's clear the requests, and then in our app let's click the Search button again. We'll see that no network requests will be made, but the data is rendered. So, the data must be coming from...