Add methodParameterSegments to input parameter types for override decorator support

docs/samples/client/csharp/SampleService/main.tsp

@@ -466,6 +466,20 @@ model XmlModelWithNamespace {
   foo: string;
 }
 
+model Wrapper {
+  @doc("header parameter")
+  @header
+  p1: string;
+
+  @doc("body parameter")
+  @body
+  action: RoundTripModel;
+
+  @doc("path parameter")
+  @path
+  p2: string;
+}
+
 union DaysOfWeekExtensibleEnum {
   string,
   Monday: "Monday",
@@ -500,13 +514,16 @@ op helloAgain(
 @route("/noContentType")
 @doc("Return hi again")
 @get
-@convenientAPI(false)
 op noContentType(
   @header p1: string,
   @body action: RoundTripModel,
   @path p2: string,
 ): RoundTripModel;
 
+op noContentTypeOverride(info: Wrapper): RoundTripModel;
+
+@@override(noContentType, noContentTypeOverride);
+
 @route("/demoHi")
 @doc("Return hi in demo2")
 @get

packages/http-client-csharp/emitter/src/lib/client-converter.ts

@@ -21,6 +21,7 @@ import {
 import {
   fromMethodParameter,
   fromSdkServiceMethod,
+  getMethodParameterSegments,
   getParameterDefaultValue,
 } from "./operation-converter.js";
 import { fromSdkType } from "./type-converter.js";
@@ -182,6 +183,7 @@ function fromSdkClient(
         skipUrlEncoding: false,
         readOnly: isReadOnly(parameter),
         crossLanguageDefinitionId: parameter.crossLanguageDefinitionId,
+        methodParameterSegments: getMethodParameterSegments(sdkContext, parameter),
       });
     }
     return parameters;

packages/http-client-csharp/emitter/src/lib/operation-converter.ts

@@ -449,6 +449,7 @@ function fromQueryParameter(
     decorators: p.decorators,
     crossLanguageDefinitionId: p.crossLanguageDefinitionId,
     readOnly: isReadOnly(p),
+    methodParameterSegments: getMethodParameterSegments(sdkContext, p),
   };
 
   sdkContext.__typeCache.updateSdkOperationParameterReferences(p, retVar);
@@ -480,6 +481,7 @@ function fromPathParameter(
     decorators: p.decorators,
     readOnly: isReadOnly(p),
     crossLanguageDefinitionId: p.crossLanguageDefinitionId,
+    methodParameterSegments: getMethodParameterSegments(sdkContext, p),
   };
 
   sdkContext.__typeCache.updateSdkOperationParameterReferences(p, retVar);
@@ -510,6 +512,7 @@ function fromHeaderParameter(
     readOnly: isReadOnly(p),
     decorators: p.decorators,
     crossLanguageDefinitionId: p.crossLanguageDefinitionId,
+    methodParameterSegments: getMethodParameterSegments(sdkContext, p),
   };
 
   sdkContext.__typeCache.updateSdkOperationParameterReferences(p, retVar);
@@ -538,6 +541,7 @@ function fromBodyParameter(
     decorators: p.decorators,
     readOnly: isReadOnly(p),
     crossLanguageDefinitionId: p.crossLanguageDefinitionId,
+    methodParameterSegments: getMethodParameterSegments(sdkContext, p),
   };
 
   sdkContext.__typeCache.updateSdkOperationParameterReferences(p, retVar);
@@ -928,6 +932,37 @@ function getArraySerializationDelimiter(
   return format ? collectionFormatToDelimMap[format] : undefined;
 }
 
+export function getMethodParameterSegments(
+  sdkContext: CSharpEmitterContext,
+  p: SdkHttpParameter | SdkModelPropertyType,
+): InputMethodParameter[] | undefined {
+  // methodParameterSegments is a 2D array where each segment array represents a path to a method parameter
+  // For spread body cases, there could be multiple paths, but we simplify by taking the first element
+  // We need the complete segment path (e.g., ['Params', 'foo'] for accessing params.foo)
+  const methodParameterSegments = (p as any).methodParameterSegments;
+  if (!methodParameterSegments || methodParameterSegments.length === 0) {
+    return undefined;
+  }
+
+  // Take the first segment path (simplification - no spector scenario for multiple paths yet)
+  const firstSegmentPath = methodParameterSegments[0];
+  if (!firstSegmentPath || firstSegmentPath.length === 0) {
+    return undefined;
+  }
+
+  const namespace = getClientNamespaceString(sdkContext) ?? "";
+  const methodParams: InputMethodParameter[] = [];
+
+  // Convert each element in the segment path to an InputMethodParameter
+  // This preserves the full path information (e.g., ['Params', 'foo'])
+  for (const segment of firstSegmentPath) {
+    const methodParam = segment as SdkMethodParameter;
+    methodParams.push(fromMethodParameter(sdkContext, methodParam, namespace));
+  }
+
+  return methodParams.length > 0 ? methodParams : undefined;
+}
+
 function getResponseType(
   sdkContext: CSharpEmitterContext,
   type: SdkType | undefined,

packages/http-client-csharp/emitter/src/type/input-type.ts

@@ -208,6 +208,7 @@ export interface InputQueryParameter extends InputPropertyTypeBase {
   explode: boolean;
   scope: InputParameterScope;
   serializedName: string;
+  methodParameterSegments?: InputMethodParameter[];
 }
 
 export interface InputPathParameter extends InputPropertyTypeBase {
@@ -219,6 +220,7 @@ export interface InputPathParameter extends InputPropertyTypeBase {
   serverUrlTemplate?: string;
   scope: InputParameterScope;
   serializedName: string;
+  methodParameterSegments?: InputMethodParameter[];
 }
 
 export interface InputHeaderParameter extends InputPropertyTypeBase {
@@ -228,6 +230,7 @@ export interface InputHeaderParameter extends InputPropertyTypeBase {
   isContentType: boolean;
   scope: InputParameterScope;
   serializedName: string;
+  methodParameterSegments?: InputMethodParameter[];
 }
 
 export interface InputBodyParameter extends InputPropertyTypeBase {
@@ -236,6 +239,7 @@ export interface InputBodyParameter extends InputPropertyTypeBase {
   defaultContentType: string;
   scope: InputParameterScope;
   serializedName: string;
+  methodParameterSegments?: InputMethodParameter[];
 }
 
 export interface InputEndpointParameter extends InputPropertyTypeBase {
@@ -245,6 +249,7 @@ export interface InputEndpointParameter extends InputPropertyTypeBase {
   scope: InputParameterScope;
   serializedName: string;
   isEndpoint: boolean;
+  methodParameterSegments?: InputMethodParameter[];
 }
 
 export interface InputEnumType extends InputTypeBase {