Typescript Tutorial Development Tutorials, Guides & Insights

TypeScript is a powerful language that extends JavaScript by adding static types, allowing developers to catch errors early and write more robust code. While TypeScript's basic type features are relatively straightforward, its advanced features like type manipulation and generics allow for even more expressive and efficient code. In this tutorial, we'll explore how to optimize your TypeScript code using advanced type manipulation and generics, making your applications more maintainable and less error-prone.

To get the most out of this tutorial, you should have a basic understanding of TypeScript, including how to define types, interfaces, and basic generics. If you're new to these concepts, consider reviewing them before diving into this tutorial.

const path = require('path');

module.exports = {
  entry: './src/index.ts',
  module: {
    rules: [
      {
        test: /\.tsx?$/,
        use: 'ts-loader',
        exclude: /node_modules/,
      },
    ],
  },
  resolve: {
    extensions: ['.tsx', '.ts', '.js'],
  },
  output: {
    filename: 'bundle.js',
    path: path.resolve(__dirname, 'dist'),
  },
};

Always enable strict mode in your tsconfig.json for the highest level of type safety:

After conversion, it’s crucial to ensure that your application still functions correctly:

If your project has existing tests, run them to confirm nothing broke during the conversion. If you’re using a testing framework like Jest, you may need to install type definitions:

type Readonly<T> = {
  readonly [K in keyof T]: T[K];
};

interface Car {
  make: string;
  model: string;
  year: number;
}

const myCar: Readonly<Car> = {
  make: 'Toyota',
  model: 'Corolla',
  year: 2020
};

// myCar.make = 'Honda'; // error

type IsString<T> = T extends string ? 'string' : 'not string';

type Test1 = IsString<string>; // 'string'
type Test2 = IsString<number>; // 'not string'