fix(types): use optional endpoint for inputs to serializer middleware

.changeset/many-stingrays-bow.md

@@ -0,0 +1,5 @@
+---
+"@smithy/middleware-serde": patch
+---
+
+use SerdeFunctions as input type and SerdeContext as resolved type for serde plugin

packages/middleware-serde/src/deserializerMiddleware.ts

@@ -5,6 +5,7 @@ import {
   DeserializeMiddleware,
   HandlerExecutionContext,
   ResponseDeserializer,
+  SerdeContext,
   SerdeFunctions,
 } from "@smithy/types";
 
@@ -13,9 +14,9 @@ import {
  *
  * 3rd type parameter is deprecated and unused.
  */
-export const deserializerMiddleware = <Input extends object, Output extends object, _ = any>(
+export const deserializerMiddleware = <Input extends object, Output extends object, CommandSerdeContext extends SerdeContext = any>(
   options: SerdeFunctions,
-  deserializer: ResponseDeserializer<any, any, SerdeFunctions>
+  deserializer: ResponseDeserializer<any, any, CommandSerdeContext>
 ): DeserializeMiddleware<Input, Output> => (
   next: DeserializeHandler<Input, Output>,
   context: HandlerExecutionContext
@@ -24,7 +25,7 @@ export const deserializerMiddleware = <Input extends object, Output extends obje
 ): Promise<DeserializeHandlerOutput<Output>> => {
   const { response } = await next(args);
   try {
-    const parsed = await deserializer(response, options);
+    const parsed = await deserializer(response, options as CommandSerdeContext);
     return {
       response,
       output: parsed as Output,

packages/middleware-serde/src/serdePlugin.ts

@@ -1,13 +1,13 @@
 import {
   DeserializeHandlerOptions,
   Endpoint,
-  EndpointBearer,
   MetadataBearer,
   MiddlewareStack,
   Pluggable,
   Provider,
   RequestSerializer,
   ResponseDeserializer,
+  SerdeContext,
   SerdeFunctions,
   SerializeHandlerOptions,
   UrlParser,
@@ -45,10 +45,10 @@ export type V1OrV2Endpoint = {
  *
  * Note: 2nd type parameter is deprecated and unused.
  */
-export function getSerdePlugin<InputType extends object, _, OutputType extends MetadataBearer>(
+export function getSerdePlugin<InputType extends object, CommandSerdeContext extends SerdeContext, OutputType extends MetadataBearer>(
   config: V1OrV2Endpoint & SerdeFunctions,
-  serializer: RequestSerializer<any, SerdeFunctions & EndpointBearer>,
-  deserializer: ResponseDeserializer<OutputType, any, SerdeFunctions>
+  serializer: RequestSerializer<any, CommandSerdeContext>,
+  deserializer: ResponseDeserializer<OutputType, any, CommandSerdeContext>
 ): Pluggable<InputType, OutputType> {
   return {
     applyToStack: (commandStack: MiddlewareStack<InputType, OutputType>) => {

packages/middleware-serde/src/serializerMiddleware.ts

@@ -1,7 +1,7 @@
 import {
-  EndpointBearer,
   HandlerExecutionContext,
   RequestSerializer,
+  SerdeContext,
   SerdeFunctions,
   SerializeHandler,
   SerializeHandlerArguments,
@@ -16,9 +16,9 @@ import type { V1OrV2Endpoint } from "./serdePlugin";
  *
  * Note: 3rd type parameter is deprecated and unused.
  */
-export const serializerMiddleware = <Input extends object, Output extends object, _>(
+export const serializerMiddleware = <Input extends object, Output extends object, CommandSerdeContext extends SerdeContext = any>(
   options: V1OrV2Endpoint & SerdeFunctions,
-  serializer: RequestSerializer<any, SerdeFunctions & EndpointBearer>
+  serializer: RequestSerializer<any, CommandSerdeContext>
 ): SerializeMiddleware<Input, Output> => (
   next: SerializeHandler<Input, Output>,
   context: HandlerExecutionContext
@@ -34,7 +34,7 @@ export const serializerMiddleware = <Input extends object, Output extends object
     throw new Error("No valid endpoint provider available.");
   }
 
-  const request = await serializer(args.input, { ...options, endpoint });
+  const request = await serializer(args.input, { ...options, endpoint } as CommandSerdeContext);
 
   return next({
     ...args,