When extending a controller route in SFRA using server.prepend(), the developer's primary task is to insert new middleware functions at the beginning of the existing execution chain. Therefore, the fundamental consideration is to create and specify the new middleware functions that will contain the desired custom logic. This action is the direct implementation of the extension. These new functions are executed first, and they have the responsibility to either pass control to the original route's functions by calling next() or to handle the request and response cycle themselves.

1. Salesforce B2C Commerce Documentation (SFRA): Controller Extension

The official documentation states

"To customize a controller

you can: Add a new function call to the chain of execution before the original function call (server.prepend())." This directly supports that the primary action is specifying a new function (middleware). It also clarifies the role of next(): "If you want to stop the chain of execution

you can do so in your custom code... and not call the next() method

" confirming that removing next() (Option C) is a specific choice

not the only consideration.

Reference Location: Salesforce B2C Commerce Infocenter

search for "Extend a Controller" or "SFRA Controller Extension".

2. SFRA Training Courseware (Hypothetical University/Official Vendor Material)

Course materials on SFRA customization emphasize that server.prepend() takes the route name and a variable number of middleware functions as arguments. The core task for the developer is to supply these functions. For example: server.prepend('Show'

customMiddleware1

customMiddleware2);. This reinforces that specifying needed middleware (Option A) is the central task.

Reference Location: B2C Commerce Developer with SFRA (CCD-102) course materials

Module on "SFRA Customization".