Are express.js Request events documented anywhere?

Express request object is an extension of node original request object. All events which are supported by nodejs request should be also available in express

Here is the docs for nodejs request

https://nodejs.org/api/http.html#http_class_http_clientrequest

Look at the documentation for the request object:

The req object is an enhanced version of Node’s own request object and supports all built-in fields and methods.

This then says, for example:

In a successful request, the following events will be emitted in the following order:

• 'socket'
• 'response'
• 'data' any number of times, on the res object ('data' will not be emitted at all if the response body is empty, for instance, in most redirects)
• 'end' on the res object
• 'close'