TypeScript Design Patterns Every React Developer Should Know

TypeScript has become the de facto standard for building React applications. But knowing TypeScript syntax is just the beginning—understanding design patterns is what separates good code from great code.

1. The Discriminated Union Pattern

This pattern is incredibly useful for handling different states in your React components. Instead of using multiple boolean flags, use a discriminated union:

type State =
  | { status: 'loading' }
  | { status: 'success'; data: User[] }
  | { status: 'error'; error: string };

This makes it impossible to have an invalid state combination and TypeScript will narrow the type automatically in your JSX.

2. The Builder Pattern for Complex Components

When you have components with many optional props, the builder pattern can help create a cleaner API:

const form = FormBuilder
  .create('user-form')
  .withValidation(schema)
  .withSubmitHandler(onSubmit)
  .build();

3. The Factory Pattern for Dynamic Components

Use factory functions to create components dynamically based on configuration:

function createField(config: FieldConfig): React.FC {
  switch (config.type) {
    case 'text': return TextInput;
    case 'select': return SelectInput;
    case 'date': return DatePicker;
  }
}

4. The Repository Pattern for Data Access

Abstract your data fetching logic behind a repository interface. This makes it easy to swap out data sources and test your components.

Conclusion

Design patterns aren't just academic concepts—they're practical tools that make your code more robust and maintainable. Start incorporating these patterns into your React TypeScript projects today.