Implement a Custom Interceptor

Custom interceptors

In this lesson, we’ll explore how to create and use a custom interceptor in NestJS. Custom interceptors are a powerful tool for adding cross-cutting concerns to our application, such as logging, data transformation, and error handling. We can customize them to fit the specific needs and apply them to specific routes or globally within the NestJS application.

Implement a custom interceptor—ResponseInterceptor

Next, we’ll implement ResponseInterceptor, which manipulates the request and response. We want to achieve the following:

• Provide a standardized response object. The response structure will be as follows:

  • data: This field contains the original response data from the route handler.

  • status: This field stores the HTTP status code of the response.

  • success: This field is a boolean flag indicating the success of the response.

  • error: This field is an error object set to null for successful responses.

• Convert the properties of the incoming request to camel case. ...