Best Practices for Clean and Maintainable TypeScript Code: Strong Typing and Null Checks

Writing TypeScript code may seem daunting given its complexity and the need for highest precision. However, by following a set of practices you can manage to write TypeScript code that is not only clean but is also highly maintainable. In this blog post, we delve into some of these practices that you can use to make your code easier to understand, reduce bugs, and make your fellow developers happy.

Make Use of Strong Typing

TypeScript’s most powerful tool is its ability to do static type checking. Instead of using generic types like “string” or “number”, TypeScript allows us to use strong typing. This is the practice of using specific, custom types for variables and functions. The benefit is that this could catch mistakes in your code even before it runs.

For instance, creating a custom type called “Person” and using it in the function in the example below:

interface Person {
    name: string;
    age: number;
}

function greet(person: Person) {
    console.log(`Hello, ${person.name}`);
}

In the example above, the Person type is an interface that requires a name and an age. Using this in our greet function means that TypeScript will throw an error if we attempt to use this function with objects that do not meet the exact Person type.

Avoid Any Type As Much As Possible

It may feel tempting to use the “any” type in TypeScript. It gives you the flexibility of assigning any type of value to a variable. However, this could lead into numerous issues down the line because it makes the code less reliable and harder to maintain. Instead, using more specific types (as explained above) and union types wherever possible can help catch errors well in advance.

For instance, here is how any type can be liberally used:

function addValues(value1: any, value2: any): any {
    return value1 + value2;
}

A better approach would be a function where you specify the exact types:

function addNumbers(num1: number, num2: number): number {
    return num1 + num2;
}

Employ Strict Null Checks

Enabling strict null checks can help you avoid potential errors related to null and undefined. This forces you to explicitly handle these cases and catches potential problems at compile-time. This means errors related to null or undefined values can be avoided even before the code actually runs.

To enable strict null checks, add the following line to your tsconfig.json file:

{
    "compilerOptions": {
        "strictNullChecks": true
    }
}

In conclusion, TypeScript gives us powerful tools such as strong typing and strict null checks, to prevent bugs and make our code more maintainable. The allure of using any type might seem great, but it can lead to harder-to-maintain code in the long run. These practices will help you to write better, more maintainable code in TypeScript.

Tags: #TypeScript #StrongTyping #StrictNullCheck #CodingBestPractices

[Reference Link](!https://blog.bitsrc.io/best-practices-for-writing-clean-and-maintainable-typescript-code-1cc6a7f029dc)