In the last few years, there has been a noticeable shift in the number of testers and testing frameworks using JavaScript. This is largely due to the increasing adoption of JavaScript-based libraries (e.g., React) in web development. But why? Why move away from a strong object oriented programming (OOP) language like Java, which has a massive community, in favor of a relatively new testing ecosystem based on JavaScript?
Let’s explore this shift from different perspectives. Grab a cup of coffee, and let's dive in!
Language in the Context of the Product Under Testing
During my time at one of the biggest automotive companies, we implemented frameworks using C, one of the low-level languages. Low-level languages like C operate closer to the hardware, giving you fine-grained control over memory and system resources. This makes them extremely powerful for environments where performance and efficiency are critical, for example, in embedded systems with limited CPU, memory, and storage.
However, this level of control comes at a cost. Writing in low-level languages requires managing many aspects manually, such as memory allocation and deallocation, error handling, and interacting directly with hardware components. As a result:
- Code complexity increases, making it harder to read and maintain.
- Development cycles are longer, as debugging and optimisation require more effort.
- Adding new features or extending the framework becomes time-consuming and error-prone.
Despite these challenges, we used C because our testing target had extremely limited resources. To write tests that could run efficiently and interact seamlessly with the software under test.
With modern web applications relying heavily on JavaScript and TypeScript, it was inevitable that testing frameworks would follow. A perfect example is Cypress, a framework that, while supporting only JavaScript and TypeScript, has gained significant traction in the testing community.
For instance, comparing test execution times in Cypress versus Selenium shows a major difference. Cypress executes test cases directly in the browser, eliminating the need for a mediator server. In contrast, Selenium requires an intermediary (WebDriver) to translate test commands into browser actions, which introduces additional latency.
This evolution fundamentally changed the scope of what we can achieve with test cases.
Why Choose TypeScript Over JavaScript for Testing?
At this point, you might be thinking, "JavaScript works well for testing, but why should I switch to TypeScript?" The answer is simple: If you can get the Pro version of something at the same cost, why settle for less?
While writing tests in JavaScript is perfectly fine, using TypeScript will elevate your testing framework by making it stronger, smarter, and more reliable.
1️⃣ Strong Typing and Type Safety
Coming from an OOP background, it can be unsettling to work in JavaScript, where variables don’t require explicit types. With TypeScript, this is no longer a concern! Strong typing ensures that you don't accidentally assign, for example, a number to a string variable. This leads to:
- Fewer Bugs: TypeScript catches type-related errors at compile time rather than at runtime, reducing debugging efforts.
- Improved Documentation: Explicit type definitions act as a built-in guide for your code
Example: Type Safety in Action
JavaScript:
function add(a, b) {
return a + b; // Potential issue: What if 'a' or 'b' is not a number?
}
console.log(add("5", 10)); // Output: "510" (unexpected result)
TypeScript:
function add(a: number, b: number): number {
return a + b;
}
console.log(add(5, 10)); // Output: 15 (expected result)
With TypeScript, you get:
✔ Fewer Bugs: TypeScript catches type-related errors at compile time, reducing debugging efforts.
✔ Improved Documentation: Explicit type definitions act as a built-in guide for your code.
2️⃣ Enhanced Tooling and Developer Experience
One of the challenges I faced when using JavaScript was the lack of intelligent autocompletion. Without explicit types, I often had to navigate through class definitions manually to understand their structure, which was time-consuming.
TypeScript dramatically improves developer experience by providing:
- Autocompletion and IntelliSense: Predicts method names, properties, and expected data types.
- Error Detection: Highlights potential bugs before execution.
- Refactoring Support: Simplifies code modifications and enhances maintainability.
3️⃣ More Reasons to Choose TypeScript for Testing
- Better Code Organisation: Interfaces and types help structure large-scale projects.
- Object-Oriented Features: Supports interfaces, generics, and abstract classes.
- Scalability: Easier to scale testing frameworks as projects grow
- Backward Compatibility: Works seamlessly with existing JavaScript code.
- Community and Industry Adoption: Major projects and frameworks now recommend TypeScript.
Getting Started with TypeScript in Testing
If you already have a background in JavaScript, transitioning to TypeScript is relatively easy. Since TypeScript is a superset of JavaScript, the learning curve is minimal. Here’s how you can get started:
- Install TypeScript:
npm install -g typescript - Compile TypeScript Code:
tsc filename.ts - Enable TypeScript in a Project:
tsc --init - Use TypeScript with a Testing Framework:
- Configure TypeScript for Cypress, or Playwright.
- Leverage TypeScript's static typing for robust test cases.
Final Thoughts: The Future of Testing is TypeScript
JavaScript has been a game-changer in the testing world, but TypeScript takes it to the next level.
If you're looking for:
Fewer bugs
Better tooling
Improved scalability
A more efficient workflow
… Then switching to TypeScript is a no-brainer!
So, are you ready to take your testing framework to the next level? Our teams can provide expert TypeScript support. Let’s talk! Email projects@spritecloud.com to get started.