chore: address comments and add diff for build generate-protocol-tests

Author: smilkuri

packages/middleware-endpoint/src/adaptors/createConfigValueProvider.ts

@@ -9,20 +9,29 @@ import type { Endpoint, EndpointV2 } from "@smithy/types";
  *                                    it will most likely not contain the config
  *                                    value, but we use it as a fallback.
  * @param config - container of the config values.
+ * @param isClientContextParam - whether this is a client context parameter.
  *
  * @returns async function that will resolve with the value.
  */
 export const createConfigValueProvider = <Config extends Record<string, unknown>>(
   configKey: string,
   canonicalEndpointParamKey: string,
-  config: Config
+  config: Config,
+  isClientContextParam = false
 ) => {
   const configProvider = async () => {
-    // Check clientContextParams first for client context parameters
-    const clientContextParams = config.clientContextParams as Record<string, unknown> | undefined;
-    const nestedValue: unknown = clientContextParams?.[configKey] ?? clientContextParams?.[canonicalEndpointParamKey];
-    // Fall back to direct config properties
-    const configValue: unknown = nestedValue ?? config[configKey] ?? config[canonicalEndpointParamKey];
+    let configValue: unknown;
+    
+    if (isClientContextParam) {
+      // For client context parameters, check clientContextParams first
+      const clientContextParams = config.clientContextParams as Record<string, unknown> | undefined;
+      const nestedValue: unknown = clientContextParams?.[configKey] ?? clientContextParams?.[canonicalEndpointParamKey];
+      configValue = nestedValue ?? config[configKey] ?? config[canonicalEndpointParamKey];
+    } else {
+      // For built-in parameters, only check direct config properties
+      configValue = config[configKey] ?? config[canonicalEndpointParamKey];
+    }
+    
     if (typeof configValue === "function") {
       return configValue();
     }

packages/middleware-endpoint/src/adaptors/getEndpointFromInstructions.ts

@@ -78,11 +78,6 @@ export const resolveParams = async <
   instructionsSupplier: EndpointParameterInstructionsSupplier,
   clientConfig: Partial<EndpointResolvedConfig<T>> & Config
 ) => {
-  // Initialize clientContextParams to empty object if undefined
-  const config = clientConfig as typeof clientConfig & { clientContextParams?: Record<string, unknown> };
-  if (config.clientContextParams === undefined) {
-    config.clientContextParams = {};
-  }
   const endpointParams: EndpointParameters = {};
   const instructions: EndpointParameterInstructions = instructionsSupplier?.getEndpointParameterInstructions?.() || {};
 
@@ -95,8 +90,10 @@ export const resolveParams = async <
         endpointParams[name] = commandInput[instruction.name] as string | boolean;
         break;
       case "clientContextParams":
+        endpointParams[name] = await createConfigValueProvider<Config>(instruction.name, name, clientConfig, true)();
+        break;
       case "builtInParams":
-        endpointParams[name] = await createConfigValueProvider<Config>(instruction.name, name, clientConfig)();
+        endpointParams[name] = await createConfigValueProvider<Config>(instruction.name, name, clientConfig, false)();
         break;
       case "operationContextParams":
         endpointParams[name] = instruction.get(commandInput);

private/my-local-model-schema/src/endpoint/EndpointParameters.ts

@@ -1,5 +1,5 @@
 // smithy-typescript generated code
-import type { Endpoint, EndpointParameters as __EndpointParameters, EndpointV2, Provider } from "@smithy/types";
+import { type Endpoint, type EndpointV2, EndpointParameters as __EndpointParameters, Provider } from "@smithy/types";
 
 /**
  * @public

private/my-local-model/src/endpoint/EndpointParameters.ts

@@ -1,5 +1,5 @@
 // smithy-typescript generated code
-import type { Endpoint, EndpointParameters as __EndpointParameters, EndpointV2, Provider } from "@smithy/types";
+import { type Endpoint, type EndpointV2, EndpointParameters as __EndpointParameters, Provider } from "@smithy/types";
 
 /**
  * @public

private/smithy-rpcv2-cbor-schema/src/endpoint/EndpointParameters.ts

@@ -1,5 +1,5 @@
 // smithy-typescript generated code
-import type { Endpoint, EndpointParameters as __EndpointParameters, EndpointV2, Provider } from "@smithy/types";
+import { type Endpoint, type EndpointV2, EndpointParameters as __EndpointParameters, Provider } from "@smithy/types";
 
 /**
  * @public

private/smithy-rpcv2-cbor/src/endpoint/EndpointParameters.ts

@@ -1,5 +1,5 @@
 // smithy-typescript generated code
-import type { Endpoint, EndpointParameters as __EndpointParameters, EndpointV2, Provider } from "@smithy/types";
+import { type Endpoint, type EndpointV2, EndpointParameters as __EndpointParameters, Provider } from "@smithy/types";
 
 /**
  * @public

smithy-typescript-codegen/src/main/java/software/amazon/smithy/typescript/codegen/endpointsV2/EndpointsV2Generator.java

@@ -259,7 +259,7 @@ private void generateEndpointParameters() {
                                 if (hasDefaultsForResolve) {
                                     writer.write(
                                         "clientContextParams: Object.assign(clientContextParamDefaults, "
-                                        + "options.clientContextParams ?? {}),"
+                                        + "options.clientContextParams),"
                                     );
                                 } else {
                                     writer.write(

smithy-typescript-codegen/src/test/java/software/amazon/smithy/typescript/codegen/endpointsV2/EndpointsV2GeneratorTest.java

@@ -56,7 +56,7 @@ public void containsExtraContextParameter() {
                   return Object.assign(options, {
                     stage: options.stage ?? "production",
                     defaultSigningName: "",
-                    clientContextParams: Object.assign(clientContextParamDefaults, options.clientContextParams ?? {}),
+                    clientContextParams: Object.assign(clientContextParamDefaults, options.clientContextParams),
                   });
                 """));
         assertThat(endpointParameters, containsString(