only convert to type object for body parameter (#3195)

Author: chunyu3

src/AutoRest.CSharp/LowLevel/Output/OperationMethodChainBuilder.cs

@@ -224,7 +224,7 @@ private ConvenienceMethod BuildConvenienceMethod(ReturnTypeChain returnTypeChain
                     else
                     {
                         // we do not support arrays as a body type, therefore we change the type to object on purpose to emphasize this: https://github.com/Azure/autorest.csharp/pull/3044
-                        if (TypeFactory.IsList(convenienceParameter.Type))
+                        if (TypeFactory.IsList(convenienceParameter.Type) && convenienceParameter.RequestLocation == RequestLocation.Body)
                         {
                             parameterList.Add(convenienceParameter with { Type = new CSharpType(typeof(object)) });
                         }

test/TestProjects/CollectionFormat-Cadl/CollectionFormat-Cadl.cadl

@@ -31,20 +31,25 @@ model Thing {
 
 @get
 @route("/csvQuery")
+@convenientAPI(true)
 op csvQuery(@query({format: "csv"}) options?: string[]): Thing;
 
 @get
 @route("/multiQuery")
+@convenientAPI(true)
 op multiQuery(@query({format: "multi"}) options?: string[]): Thing;
 
 @get
 @route("/noFormatQuery")
+@convenientAPI(true)
 op noFormatQuery(@query options?: string[]): Thing;
 
 @get
 @route("/csvHeader")
+@convenientAPI(true)
 op csvHeader(@header({format: "csv"}) options?: string[]): Thing;
 
 @get
 @route("/noFormatHeader")
+@convenientAPI(true)
 op noFormatHeader(@header options?: string[]): Thing;

test/TestProjects/CollectionFormat-Cadl/Generated/ArrayAsQueryOrHeaderClient.cs

@@ -0,0 +1,42 @@
+// Copyright (c) Microsoft Corporation. All rights reserved.
+// Licensed under the MIT License.
+
+// <auto-generated/>
+
+#nullable disable
+
+using System.Text.Json;
+using Azure;
+using Azure.Core;
+
+namespace ArrayAsQueryOrHeader.Models
+{
+    public partial class Thing
+    {
+        internal static Thing DeserializeThing(JsonElement element)
+        {
+            if (element.ValueKind == JsonValueKind.Null)
+            {
+                return null;
+            }
+            string name = default;
+            foreach (var property in element.EnumerateObject())
+            {
+                if (property.NameEquals("name"u8))
+                {
+                    name = property.Value.GetString();
+                    continue;
+                }
+            }
+            return new Thing(name);
+        }
+
+        /// <summary> Deserializes the model from a raw response. </summary>
+        /// <param name="response"> The response to deserialize the model from. </param>
+        internal static Thing FromResponse(Response response)
+        {
+            using var document = JsonDocument.Parse(response.Content);
+            return DeserializeThing(document.RootElement);
+        }
+    }
+}

test/TestProjects/CollectionFormat-Cadl/Generated/Models/Thing.Serialization.cs

@@ -0,0 +1,29 @@
+// Copyright (c) Microsoft Corporation. All rights reserved.
+// Licensed under the MIT License.
+
+// <auto-generated/>
+
+#nullable disable
+
+using System;
+using Azure.Core;
+
+namespace ArrayAsQueryOrHeader.Models
+{
+    /// <summary> The Thing. </summary>
+    public partial class Thing
+    {
+        /// <summary> Initializes a new instance of Thing. </summary>
+        /// <param name="name"> the object name. </param>
+        /// <exception cref="ArgumentNullException"> <paramref name="name"/> is null. </exception>
+        internal Thing(string name)
+        {
+            Argument.AssertNotNull(name, nameof(name));
+
+            Name = name;
+        }
+
+        /// <summary> the object name. </summary>
+        public string Name { get; }
+    }
+}