fix(headless): make CommerceEngineDefinitionOptions an optional gen…

…eric type (#4703)

https://coveord.atlassian.net/browse/KIT-3713

The goal of this is for the implementer to not have to interact with the
`ControllerDefinitionsMap` & the `Controller` interface. These are
**internal** and bring more complexity to the implementer than anything
else. We can't simply remove that generic since it is used in
headless-react for inference but we can make it optional.

turns out this easier than I thought 😅. I did not think of simply making
it optional

packages/headless/src/app/commerce-ssr-engine/factories/build-factory.ts

@@ -34,7 +34,8 @@ export interface SSRCommerceEngine extends CommerceEngine {
 }
 
 export type CommerceEngineDefinitionOptions<
-  TControllers extends ControllerDefinitionsMap<Controller>,
+  TControllers extends
+    ControllerDefinitionsMap<Controller> = ControllerDefinitionsMap<Controller>,
 > = EngineDefinitionOptions<CommerceEngineOptions, TControllers>;
 
 function isListingFetchCompletedAction(action: unknown): action is Action {

packages/samples/headless-ssr-commerce/lib/commerce-engine-config.ts

@@ -1,6 +1,4 @@
 import {
-  Controller,
-  ControllerDefinitionsMap,
   CommerceEngineDefinitionOptions,
   defineProductList,
   defineCart,
@@ -23,10 +21,6 @@ import {
   defineRecommendations, //defineParameterManager,
 } from '@coveo/headless-react/ssr-commerce';
 
-type CommerceEngineConfig = CommerceEngineDefinitionOptions<
-  ControllerDefinitionsMap<Controller>
->;
-
 export default {
   // By default, the logger level is set to 'warn'. This level may not provide enough information for some server-side errors. To get more detailed error messages, set the logger level to a more verbose level, such as 'debug'.
   // loggerOptions: {level: 'debug'},
@@ -65,4 +59,4 @@ export default {
     facetGenerator: defineFacetGenerator(),
     breadcrumbManager: defineBreadcrumbManager(),
   },
-} satisfies CommerceEngineConfig;
+} satisfies CommerceEngineDefinitionOptions;