Tips and Tricks That Every Typescript Developer Should Know
Tags: typescript, programming, productivity, learning
Published: 2023-05-21 12:04:17

#Tips and Tricks for TypeScript Developers

TypeScript has become the go-to language for building scalable web applications in recent years. It is a superset of JavaScript that offers static typing and a host of other features, making it easier to write code that is less error-prone and more maintainable.
If you are a TypeScript developer or looking to become one, here are some tips and tricks you should know to enhance your development.
![Image](https://media.giphy.com/media/1xne5qPyBA5GGouLyo/giphy.gif)


###1. Embrace the Type System
one of the primary advantages of typescript is its type system, which allows you to catch potential bugs at compile-time. Ensure that you take advantage of the type system in TypeScript by thoroughly annotating your types.

Example:
```javascript
function add(a: number, b: number): number {
   return a + b;
}
```

###2. Use Generics
Generic types allow you to write reusable code that can adapt to different types easily. This feature can save you time and lines of code by allowing you to define functions and classes that work with multiple data types.

Example:
```javascript
interface IProduct<T> {
  id: string;
  name: string;
  price: T;
}


const product: IProduct<number> = {
    id: '1234',
    name: 'Product Name',
    price: 500,
};

```
###3. Take Advantage of Enums
An enum is a type of data that allows a variable to have one of several predefined values. They help you keep your code maintainable and easy to understand by defining a set of related values.

Example:
```javascript
enum Direction {
  LEFT,
  RIGHT,
  UP,
  DOWN,
}

let direction = Direction.LEFT;
```

###4. Use Intersection Types
Intersection types allow you to merge multiple types into a single type.

Example:
```javascript
type X = {
  x: string;
};

type Y = {
  y: string;
};

type XY = X & Y;

const xy: XY = { x: 'hello', y: 'world' };
```

###5. Use Optional Chaining
Optional chaining allows you to access nested properties or methods without having to check if each level exists.
Example:
```javascript
const name = user?.firstName ?? 'Unknown';
```

###6. Use Nullish Coalescing
Nullish coalescing allows you to provide a default value when a value is null or undefined.
Example:
```javascript
const name = user.firstName ?? 'Unknown';
```

###7. Use Read-Only Properties
Read-only properties ensure that a property value cannot be changed after it is instantiated, including in constructors.
Example:
```javascript
class Person {
  readonly name: string;

  constructor(name: string) {
    this.name = name;
  }
}
```

###8. Use Destructuring
Destructuring allows you to extract values from objects and arrays into separate variables.
Example:
```javascript
const { firstName, lastName } = user;
```

###9. Use Type Aliases
Type aliases allow you to create a name for a type that is used multiple times.
Example:
```javascript
type User = {
  firstName: string;
  lastName: string;
};

function greet(user: User) {
  console.log(`Hello, ${user.firstName} ${user.lastName}`);
}
```

###10. Use Type Assertions
Type assertions allow you to tell TypeScript to treat a value as a specific type in specific situations.
Example:
```javascript
const x: unknown = 'hello world';
const y = (x as string).toUpperCase();
```

###11. Use the never Type
The never type represents a value that will never occur.
Example:
```javascript
function fail(message: string): never {
  throw new Error(message);
}
```

###12. Use the Spread Operator
The spread operator allows you to create a new array or object by merging existing ones.
Example:
```javascript
const numbers = [1, 2, 3];
const newNumbers = [...numbers, 4, 5, 6];
```

###13. Use Union Types
Union types allow you to define a type that can have one of several types.
Example:
```javascript
type Status = 'success' | 'failure';

function getStatus(status: Status) {
  console.log(`status is ${status}`);
}
```

###14. Use Enums for String Literals
Enums can also be used to define string literals.
Example:
```javascript
enum Status {
  Success = 'Success',
  Failure = 'Failure',
}

function getStatus(status: Status) {
  console.log(`status is ${status}`);
}

```

###15. Use keyof to get Keys of Objects
The keyof keyword allows you to get the keys of an object.
Example:
```javascript
type User = {
  firstName: string;
  lastName: string;
};

const keys: Array<keyof User> = ['firstName', 'lastName'];
```

###16. Use typeof to get the Type of a Variable
The typeof keyword allows you to get the type of a variable at runtime.
Example:
```javascript
const x = 10;
const y: typeof x = 20;
```

###17. Use in Operator For Checking Properties of Objects
The in operator allows you to check if a property exists on an object.
Example:
```javascript
type User = {
  firstName?: string;
  lastName?: string;
};

function greet(user: User) {
  if ('firstName' in user) {
    console.log(`Hello, ${user.firstName}`);
  } else {
    console.log('Hello');
  }
}
```

###18. Use String Interpolation
String interpolation allows you to embed expressions in string literals.
Example:
```javascript
const firstName = 'John';
const lastName = 'Doe';
console.log(`Hello, ${firstName} ${lastName}`);
```

###19. Use typeof for Type Guards
Using typeof in conjunction with if-else statements can serve as an alternative to type guard syntax.
Example:
```javascript
function example(foo: string | number): void {
  if (typeof foo === 'string') {
    console.log('string');
  } else {
    console.log('number');
  }
}
```

###20. Use export * as to Re-Export Modules
The export * as syntax allows you to re-export all named exports of a module under a separate namespace.
Example:
```javascript
// module1.ts
export const foo = 1;
export const bar = 2;

// module2.ts
export * as module1 from './module1';
```

###21. Use Tuples for Fixed-Length Arrays
Tuples allow you to define an array with a fixed number of elements, with different types.

Example:
```javascript
const tuple: [number, string] = [1, 'hello'];
```

###22. Utilize TSLint
TSlint is a tool that provides linters for TypeScript, statically analyzing the code and providing guidelines on how to improve the quality of the codebase, resulting in cleaner and quality code.

Example:
```javascript
 npm install -g tslint

```

##Conclusion
The techniques discussed in this article are a good starting point for becoming a Typescript developer, knowing the basics will save one a lot of shoot-my-foot moments during the code review and debugging phase.
These are just a few tips and tricks that can greatly improve your development with TypeScript. Other options include applying object-oriented approaches and utilizing external libraries correctly. By applying these techniques and more, you can employ the full capabilities of TypeScript, building robust, scalable applications.