The list of benefits that TypeScript adoption promises makes many software development companies wonder if there’s a safe way to replace JavaScript code with it. Sometimes described as “JavaScript with superpowers”, this invention of the Microsoft company enables some new features, such as assigning static types to variables, for example.

But since modern web app development is a multilayer and complex process, the migration may become much more complicated than replacing a bunch of JavaScript files with TypeScript ones. Also, considering that some projects may last months or even years, sometimes you’ll be forced to make changes on-the-run. However, following some best practices tips, you can minimize potential risks and switch to TypeScript code usage as smoothly as possible. Today, we will share some of them with you.

Tips on Hassle-free TypeScript Migration

First, Set the Purpose of Code Improvements

Any programming language or library you normally use to write the application’s source code, be it JavaScript, TypeScript, or any other one from the myriads of technologies, has specific kinds of projects it suits better, advantages, and other characteristics. Currently, JavaScript is one of the most widely used programming languages and definitely the number one choice for those who’s into web development.

However, engineering tools aren’t prone to design flaws. Therefore, at some point, you may find out that the language you’re currently using doesn’t fully correspond to your needs. Here, you must clearly understand what outcomes to expect from the migration not to end up at the starting point again. Say if you seek for strict typing guidelines, faster compilation, and good code readability both for experienced team members and newcomers, you can think of TypeScript as one of the viable options.

Do Not Neglect the Team Members Opinion

Some love to tell their team members things like “we’re one big family here” and migration from JavaScript to TypeScript can be an excellent opportunity to prove it. Most probably, TypeScript won’t be your only option if one day you decide to change the way you write the code. Also, there’s always a chance that after some thought, you decide you’re happy with the way things are now.

In any case, it’ll be a good idea to allow your development team to take part in making this decision. Devs can research the differences between what tools they use and those you plan to adopt, ask some questions, and make assumptions about the feasibility of change.

Ensure Gradual Migration of Your JS Files to TS

Here’s another obstacle that may harden your transition to a 100% TypeScript development company. JavaScript code is stored in .js files, while TypeScript uses .ts or .tsx files. If you decide to use TypeScript for some of your projects, you’ll have to change the files accordingly, add signatures, build types and interfaces, and pay due attention to testing to ensure that these changes break nothing.

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It’s important not to rush with this file routine, not to bite off more than you can chew. If you follow an incremental SDLC model, such as Scrum, everything can go pretty smoothly. For example, in this case, developers can change a fixed number of files on each sprint, see how well everything went, and proceed with other project parts at the next sprint.

Develop a Migration Plan and Write it Down as a Guideline

Every critical task, despite the seeming simplicity like in the case of file manipulations, must not be performed without developing a detailed plan beforehand. Migration to TypeScript must not break the consistency of the code style, since the development project involves many people working together and implies that other programmers will have to deal with code created long before they first started working on the project.

For this purpose, you can analyze the code you already have and determine which standards all developers should follow when they start using TypeScript instead of the current programming language. A guideline that you will create this way may contain such details as types and interfaces, naming conventions, third-party tools configuration, and other info.

Prepare Yourself to Face Documentation Written for JavaScript Only

TypeScript definitely deserves its place under the sun and there are no barriers that wouldn’t allow you to make it a part of your development toolset. Almost. The thing is that despite the growing popularity of TypeScript, you can’t ignore the fact that previous decades of writing code for the web have been dominated by JavaScript.

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Therefore, one day you may find yourself one on one with a library not originally written in TypeScript. Using such libraries and dynamic APIs they deliver may become a real challenge, especially considering that there may be no proper documentation available.

It May Turn Out That Everything is More Complicated Than You Thought

You may often see that somebody describes TypeScript as JavaScript with types. Such wording allows you to get first impressions on this programming language and understand how it can help you enrich your code. However, don’t let this formula mislead you and don’t forget that TypeScript is a different language.

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Experienced JavaScript programmers will face fewer problems adopting it compared to newbies. Even so, it’ll require more effort than just turning some JS files into TS/TSX. Its own rules of writing the code, types, declarations, and tones of other aspects can make TypeScript usage not as easy as you would like.


Adopting a new dev tool is always a challenge. You’ll have to go through a thorny path of planning, careful implementation, and testing before newly adopted technologies bear fruit. Despite all the similarities that JavaScript and TypeScript have (just look at their names), the migration process is fraught with some non-obvious challenges. To avoid them, one should not buy into the apparent commonality of these technologies and approach the process carelessly. Creating a detailed plan involving the development team is always a good starting point. Approaching the migration process gradually, starting with files that have not too many dependencies with mandatory follow-up testing, won’t harm as well.

If you’re looking for an experienced team of web developers that knows TypeScript features like the back of its hand, please contact us.