Blog
From JavaScript to TypeScript: How to Upgrade Your Code with Advanced Features and Best Practices
14/10/2024
5 minutes 36 seconds read
From JavaScript to TypeScript: How to Upgrade Your Code with Advanced Features and Best Practices
Shashank Jain
Introduction of JavaScript to TypeScript
As we will discover throughout this article, web development is a field that is in a constant state of change, and therefore, it is essential to be up to date with the innovations. Another rapidly advancing stream of development is the increasing usage of TypeScript, which is deemed to be JavaScript’s superset.
Though JavaScript is still considered one of the main languages for developing web applications, with control over interactivity and dynamic functions, TypeScript provides more superior features that help enhance coding processes. By adopting these advancements, developers can create better and more sustainable web applications.
Brief History of Javascript and Typescript
Web browsers were the original intended application for JavaScript, which Brendon Eich created in 1995. It has become very popular for enhancing interactivity in organization’s web-based systems.
As more and more web applications started employing more extraordinary features, the developers found themselves in need of writing more compact and less error-prone code. This led Microsoft to create a new language called TypeScript in the year 2012.
TypeScript is syntactically backward compatible with JavaScript; this means that any JavaScript code is also valid TypeScript. It has optional static typing, classes, and other features to enhance its construction for large applications.
TypeScript is built on top of JavaScript and compiles its applications into standard JavaScript; therefore, TypeScript applications can run on any platform where JavaScript runs. That is why TypeScript is becoming more popular; it adds optional static typing to JavaScript, which makes errors easier to find and code more understandable.
Migrating JavaScript to TypeScript: Basic Type Annotations
When it comes to migrating your JavaScript code to TypeScript, the JS2TS tool is definitely a help in the process. It begins with appending primary-type declarations to your already-written script. This means it attempts to infer the characteristics of the data that each variable contains, be it strictly numeric, string data, or objects, for instance. This means that errors are detected early and your code becomes easier to maintain.
The JS2TS tool also converts functions as well as classes into TypeScript. In the case of functions, it combines type information with parameters and output values. In this regard, it makes it easier to understand the type of data that each component of your class is processing.
The first, and perhaps the main, issue that arises when switching to TypeScript is working with third-party libraries. The JS2TS tool can help here too In the next part, this paper will demonstrate the applicability and effectiveness of the JS2TS tool in the identification of typecast errors and the provision of corresponding solutions.
Advanced TypeScript Features
There are other additional features that are implemented in TypeScript that enable it to perform more than just type checking. These features enable the developers to come up with better and more reliable code.
They extend JavaScript further with layers of type safety and other concepts of higher programming languages. If you are migrating from JavaScript using tools such as JS2TS, it is crucial to know these advanced attributes to help you with TypeScript development.
Here are some, as follows:
Generics in TypeScript:Generics are like types but more like customizable boxes in TypeScript that can accept any type. Think of a box where you can place any kind of item in it—that’s the role of generics in your code.
When you are using the JS2TS tool to convert the code from JavaScript to TypeScript , there are often cases were knowing about generics can make your code much more flexible and more typed. Through generics, you can sort the arrays through numbers or strings and the generic function will work through type checking.
Decorators in TypeScript:This is a special marker that can be placed on classes, methods, or properties and modify their functions or provide extra detail. Imagine them as the extra abilities that you apply to your code through the stickers.
Throughout the process of JavaScript to TypeScript conversion with the help of the JS2TS tool, you may look at using decorators to extend existing classes or methods. For example, it is possible to create a decorator that would continuously log its method calls or another one that would add validation to the class’s properties.
Modules in TypeScript:Modules in TypeScript are a phenomenon that have been implanted with the purpose of dividing the code into separate, reusable sections. They are like chapters in a book, where each one contains codes of the same kind. When you follow through on a JavaScript project with the JS2TS tool , you will visually come across or develop modules within your project.
Using TypeScript, functions, classes, and variables can be exported or imported from one file to another, which is very useful when working on large projects and to avoid naming collisions. They also allow you to align more pleasing- looking and easier-to-maintain construction configurations.
Best practices for a smooth transition
Code Organization:If you are using the JS2TS tool, which is the process of converting JavaScript to TypeScript, it is best to do this when your code is clean. First, to keep your files unrestricted and arranged, it is necessary to sort them by the functions they perform. This structure will make it easy to find your way into the project as you transition from one section to the next.
Moreover, it is advised to divide large files into more tractable modules, which may be useful. In this regard, the approach enhances code readability and, at the same time, facilitates efficient processing of your code by the JS2TS tool. When converting the files, use file naming conventions as well as the naming conventions of the functions to make it easier to understand when working through the conversion process.
Linting and Formatting:Because there is a shared likelihood that you’ll be coding in TypeScript with other developers, it is recommended that you establish linting and formatting for TypeScript. As for formatting, there are tools, such as, JS2TS tool to apply linting and formatting at the time of conversion automatically.
Introducing allows for the identification of such problems as syntax errors and style differences between the two languages at the early stages of the process, so there would be no need for multiple modifications afterwards.
Continuous Integration:Continuous integration must be highly effective when the tool is applied to large-scale migration; therefore, a reliable CI pipeline should be created. Integrate the CI system so that it can always execute the JS2TS tool on your code based on every change made to your repository.
Doing so guarantees that all newly introduced JavaScript code is transpiled to TypeScript. It is necessary to add automatic tests to call from within the CI process to ensure that the converted TypeScript code is working as expected. As mentioned earlier, a thorough continuous integration (CI) setup can help identify problems early on, manage the quality of the code, and facilitate the transition process overall.
Conclusion
This transition is usually done from JavaScript to TypeScript and has the potential to enhance the quality as well as the maintainability of the code considerably. Using tools such as JS2TS and knowing your TypeScript progress, including generators, decorators, and module features, you can improve your development.
What other tools offered by JS2TS?
The application of linting, formatting, and code organization principles, along with continuous integration, will result in a successful migration process. Being a static type checker, TypeScript not only aids in finding bugs during the development process but also takes the unnecessary load off the runtime checking as your projects expand, as well as making your code base more robust and easier to manage for yourself and the other team members.