The Ultimate Guide to TypeScript

There are dozens of popular languages. Besides serving different purposes, devs also have personal preferences. This article will focus on one of our favorites: TypeScript. According to Stack Overflow's 2021 Survey, it's the seventh Most Popular Technology. Also, it's third on Most Loved. Here, we'll cover when to use it while listing its many available tools and resources. Are you ready?

What is TypeScript?

TypeScript is an open-source programming language developed by Microsoft in 2012. Its website defines it as "JavaScript with syntax for types." Often, it's referred to as the superset of JavaScript (JS). Furthermore, it's used to develop JS and web apps, combining it with other tools, such as Angular or Node.js. As a framework, it contains plain JS code plus specific keywords and constructs. For this, the code gets translated to JS through compilation. This means that any browser that supports JS can use it.

The Basic Concepts of TypeScript

1. TypeScript Types

One of the main features that TypeScript introduces is types. As a definition, these represent the properties and functions of a specific value. Also, its types get categorized: there are primitive types and object types. On the one hand, primitive types include string, number, boolean, null, and undefined. Meanwhile, object types include classes, functions, and arrays. The purpose of types is to help detect errors in the compilation. Also, they allow you to understand the connections between values and variables.

2. TypeScript Classes

Classes are special functions that mimic the class keyword. As templates, these functions work to create new objects. Although classes are present in JS, TypeScript adds some twists. Some of them include type designations to members and parameters of methods. This allows you to use object-oriented techniques such as abstraction and encapsulation. Classes are great to use when you know you will need to change the state of an object over time. On top of that, they associate behaviors with data, among other things.

3. TypeScript Interfaces

Typescript interfaces name types and define contracts. This works both within your code and any code outside of your project. Also, they make the code easier to read by defining the properties and types that an object can have.

4. TypeScript Generics

TypeScript generics let you create reusable components. As a result, components made with generics can work with various data types. Of course, this guarantees more flexibility and scalability. These generics work like C# or Java, allowing you to make functions, classes, and interfaces.

When to use TypeScript?

Now that we’ve covered TypeScript let’s look at its usage more thoroughly. To answer the question when to use typescript, you can start by thinking about its most common scenarios:

1. Large Codebases. TypeScript's type checking can make considerable differences in reducing errors. This comes in handy both with large codebases and big work teams.

2. Potential JS Problems. A transition to TypeScript may be easier than JS if a team usually works with solid typed languages like C#. Although it's always recommended to learn JS, it's not imperative. Also, since TypeScript and C# have similar syntaxes, it's an even easier transition.

3. Frameworks and Libraries. Mixing TypeScript with Angular or Redux can help you create unique products. If you use recommended languages, you can make the most of each tool and improve its performance. Don't know any projects completed with TypeScript? Take a look at our showcase of Wurrly, an excellent educational platform.

Most Popular Typescript Frameworks

Since it stems from JavaScript, countless frameworks and libraries work well with TypeScript. We’d like to give you an overview so you have an idea of the tools available for this programming language. We’ll start with the most popular TypeScript frameworks. Then, we'll move on to its best frameworks for testing and UI.

1. Nest for TypeScript 

Released in 2018, Nest.js is one of the most popular Typescript frameworks available. Also, it’s one of the fastest-growing frameworks in the Node.js ecosystem. Through NestJS, you can build scalable and efficient Node.js web apps. This is an extensible, versatile and progressive framework. Furthermore, it includes excellent documentation and an application structure supported by Angular.

2. Feathers for TypeScript 

Feathers.js is a lightweight web framework released in 2014. Currently, it's used to create real-time apps and REST APIs. Its features simplify the development of modern web and mobile apps. FeathersJS is a minimalist web framework so that you can use it universally. Among its features, it supports both relational and non-relational databases. Moreover, it also supports authentication.

3. LoopBack for TypeScript 

LoopBack is an extensible open-source Node.js and TypeScript framework based on Express. In general, it's used to build APIs and microservices. Within its features, it has ready-to-use built-in models and access level controls. What's more, it has a built-in API explorer and API documentation.

TypeScript Testing Frameworks

1. Jest for TypeScript 

Jest is a JavaScript testing framework focused on simplicity. Not only it works with TypeScript but also with Babel, Angular, React, and more. Some of Jest's functionalities include assertions, coverage analysis, mocking, and parallel testing. This TypeScript testing framework is easy to set up and fast and does snapshots.

2. Mocha + Chai for TypeScript 

This is a fantastic framework/library combo for TypeScript testing. While Mocha is a feature-rich testing framework, Chai is an assertion library. Moreover, Chai is both BDD (behavior-driven) and TDD (test-driven development). Both of them run on Node.js and in browsers. Mocha's framework's outstanding benefit is including a test runner. As this framework does not include assertions, pairing it with Chai does the trick. You should also look into the Sinon.js library if you need test doubles.

3. Jasmine for TypeScript 

Jasmine is a BDD framework for JavaScript testing. To work, it doesn’t need a DOM nor depend on any other JS framework. As a testing framework, it's fast and has a clear and easy-to-understand syntax. Also, it's available for both Node.js and browsers. Nonetheless, the only thing not built into Jasmine is a test runner. In that case, you can use Karma.

TypeScript UI Frameworks

1. Angular for TypeScript 

We couldn’t fail to mention Angular. If you don't know, the open-source framework is wholly written with TypeScript. Angular is cross-platform, flexible, and has excellent performance and full support from Google. Also, it includes significant UI components and component libraries. There are NGX Bootstrap, Clarity, and NG Bootstrap, to name a few.

2. React Native for TypeScript 

React, The popular UI framework relies on the learn once, write anywhere paradigm. You can create Android and iOS apps with React Native. You can combine them with the beloved React JS library in both cases. As a framework, React Native it's open-source, cross-platform, and UI-design focused.

3. Vue for TypeScript 

Vue.js is an open-source, progressive JS framework. It's developer friendly, has a small but super-fast DOM, and has excellent documentation. Also, it has similarities with both Angular and React. For instance, it uses template syntax and relies on component-based architecture. On top of that, plenty of great UI libraries are also available for Vue.js. Some of these are Vuetify, Element, and Vue Material.

Popular TypeScript Libraries

We’ve already mentioned Chai for testing and React for UI in the previous section. But quite a few great libraries work amazingly with TypeScript. Since TypeScript is, in essence, an extended version of JS, all JS libraries are compatible with it. This applies either on their own or by using their extended version. If you want to tackle this language, some libraries will cover different areas. 

1. jQuery 

jQuery is an open-source, free, fast, and feature-rich JS library created in 2006. It helps with HTML document traversal and manipulation, Ajax, animation, and event handling. Also, over 75% of websites use this library. As a library, it’s lightweight and versatile and includes an easy-to-use, minimalistic API.

2. D3.js

This library gets its primary usage from manipulating data-based documents. D3.js illustrates graphs on .svg elements and makes powerful data visualizations possible. These elements are also known as Data-Driven Documents.

3. TS Toolbelt

This is the most extensive TypeScript utility library out there. Its features cover over 200 utilities, and it has a programmatic API. Moreover, every week tens of thousands of developers download TS Toolbelt.

4. Algolia Places

This library’s goal is to address auto-completion by leveraging the OpenStreetMap database. While providing a modern and clean look, Algolia Places is easy to use and extend. Also, it's able to combine places with search results.

5. Anime.js

As you might have gathered from its name, Anime.js is an animation library. Within its features, it's lightweight and has a simple and powerful API. Moreover, it works with most browsers, like Chrome, Safari, Opera, and Firefox.

6. Go.js

Go.js builds diagrams on the web with both JS and TypeScript. As a result, it creates data visualizations, graph editors, and drawing tools. Furthermore, it has automatic layouts, extensive tools, and built-in context menus and tooltips.

10 Reasons to Use TypeScript

We've gone over some examples of when to use TypeScript. Yet, this programming language has a vast amount of benefits. Here are our top 10 reasons to use TypeScript:

1. Simplifying JavaScript. This makes codes easier to read and debug.

2. Open-source. This feature makes it flexible, agile, and cost-effective.

3. Easy to read. Since it’s more explicit, it’s easier to get. This is handy if you work with developers who may not work with the same languages.

4. Powerful type system to bugs. While no programming language comes bug-free, TypeScript’s type system prevents many errors. Moreover, type-checking can save a lot of time when fixing bugs.

5. Runs everywhere. Since it stems from JS, Typescript can run anywhere JS does.

6. Large and supportive community. TypeScript has a large active community behind it. This translates into a myriad of resources and tools available. Also, countless developers are willing to help whenever a problem arises. On top of that, companies such as Google, Microsoft, and Asana share their work with the community.

7. Object-oriented programming concepts. Object-oriented programming keeps your code clean and robust, improving quality and maintainability.

8. Compatible with most third-party libraries. Since it’s compatible with JS, there were countless libraries when it launched. Moreover, this language is compatible with most third-party libraries. You can find one for pretty much anything you need.

9. Compiles to any JavaScript version. Well, at least those still in use, starting with ES3.

10. Supports static typing. Statically-typed languages have many benefits. These include protection from runtime errors, performance optimization, and IDE assistance.

Conclusion

As you can see, there are many reasons to learn and use TypeScript. Also, there are countless resources and tools available to work with it. We hope this article has given you enough information to start your journey!