feat(dpg): support logicalPath of lro

src/AutoRest.CSharp/Common/Input/CodeModelConverter.cs

@@ -167,7 +167,8 @@ public List<InputParameter> CreateOperationParameters(IReadOnlyCollection<Reques
 
             return new OperationLongRunning(
                 FinalStateVia: operation.LongRunningFinalStateVia,
-                FinalResponse: CreateOperationResponse(operation.LongRunningFinalResponse)
+                FinalResponse: CreateOperationResponse(operation.LongRunningFinalResponse),
+                ResultPath: null
             );
         }
 

src/AutoRest.CSharp/Common/Input/InputTypes/OperationLongRunning.cs

@@ -2,10 +2,30 @@
 // Licensed under the MIT License.
 
 using Azure.Core;
+using System.Linq;
+using AutoRest.CSharp.Utilities;
 
 namespace AutoRest.CSharp.Common.Input;
 
-internal record OperationLongRunning(OperationFinalStateVia FinalStateVia, OperationResponse FinalResponse)
+internal record OperationLongRunning(OperationFinalStateVia FinalStateVia, OperationResponse FinalResponse, string? ResultPath)
 {
-    public OperationLongRunning() : this(FinalStateVia: OperationFinalStateVia.Location, FinalResponse: new OperationResponse()) { }
+    public OperationLongRunning() : this(FinalStateVia: OperationFinalStateVia.Location, FinalResponse: new OperationResponse(), null) { }
+
+    /// <summary>
+    /// Meaninngful return type of the long running operation.
+    /// </summary>
+    public InputType? ReturnType
+    {
+        get
+        {
+            if (FinalResponse.BodyType is null)
+                return null;
+
+            if (ResultPath is null)
+                return FinalResponse.BodyType;
+
+            var rawResponseType = (InputModelType)FinalResponse.BodyType;
+            return rawResponseType.Properties.FirstOrDefault(p => p.SerializedName == ResultPath)!.Type;
+        }
+    }
 }

src/AutoRest.CSharp/Common/Output/Models/LongRunningOperation.cs

@@ -30,12 +30,12 @@ protected LongRunningOperation(InputOperation operation, BuildContext context, L
             FinalStateVia = operation.LongRunning.FinalStateVia;
 
             var finalResponse = operation.LongRunning.FinalResponse;
-            var finalResponseType = finalResponse.BodyType;
+            var returnType = operation.LongRunning.ReturnType;
 
-            if (finalResponseType != null)
+            if (returnType != null)
             {
-                ResultType = TypeFactory.GetOutputType(context.TypeFactory.CreateType(finalResponseType with {IsNullable = false}));
-                ResultSerialization = SerializationBuilder.Build(finalResponse.BodyMediaType, finalResponseType, ResultType, null);
+                ResultType = TypeFactory.GetOutputType(context.TypeFactory.CreateType(returnType with {IsNullable = false}));
+                ResultSerialization = SerializationBuilder.Build(finalResponse.BodyMediaType, returnType, ResultType, null);
 
                 var paging = operation.Paging;
                 if (paging != null)

src/AutoRest.CSharp/LowLevel/Generation/DpgClientWriter.cs

@@ -5,6 +5,7 @@
 using System.Collections.Generic;
 using System.Linq;
 using System.Text;
+using System.Text.Json;
 using System.Threading;
 using AutoRest.CSharp.Common.Generation.Writers;
 using AutoRest.CSharp.Common.Input;
@@ -357,12 +358,25 @@ private void WriteConvenienceLroMethod(LowLevelClientMethod clientMethod, Conven
                         .LineRaw(";");
                     // return ProtocolOperationHelpers.Convert(response, r => responseType.FromResponse(r), ClientDiagnostics, scopeName);
                     var diagnostic = convenienceMethod.Diagnostic ?? clientMethod.ProtocolMethodDiagnostic;
-                    _writer.Line($"return {typeof(ProtocolOperationHelpers)}.{nameof(ProtocolOperationHelpers.Convert)}({responseVariable:I}, {responseType}.FromResponse, {fields.ClientDiagnosticsProperty.Name}, {diagnostic.ScopeName:L});");
+                    _writer.Line($"return {typeof(ProtocolOperationHelpers)}.{nameof(ProtocolOperationHelpers.Convert)}({responseVariable:I}, {GetConvertMethodStatement(clientMethod.LongRunning!, responseType)}, {fields.ClientDiagnosticsProperty.Name}, {diagnostic.ScopeName:L});");
                 }
             }
             _writer.Line();
         }
 
+        private string GetConvertMethodStatement(OperationLongRunning longRunning, CSharpType responseType)
+        {
+            if (longRunning.ResultPath.IsNullOrEmpty())
+            {
+                return $"{responseType.Name}.FromResponse";
+            }
+
+            return @$"r => {{
+                var resultJsonElement = {typeof(JsonDocument)}.{nameof(JsonDocument.Parse)}(r.{nameof(Response.Content)}).{nameof(JsonDocument.RootElement)}.{nameof(JsonElement.GetProperty)}(""{longRunning.ResultPath}"");
+                return {longRunning.ReturnType!.Name}.Deserialize{longRunning.ReturnType.Name}(resultJsonElement);
+            }}";
+        }
+
         private void WriteConveniencePageableMethod(LowLevelClientMethod clientMethod, ConvenienceMethod convenienceMethod, ProtocolMethodPaging pagingInfo, ClientFields fields, bool async)
         {
             _writer.WritePageable(convenienceMethod, clientMethod.RequestMethod, pagingInfo.NextPageMethod, fields.ClientDiagnosticsProperty, fields.PipelineField, clientMethod.ProtocolMethodDiagnostic.ScopeName, pagingInfo.ItemName, pagingInfo.NextLinkName, async);

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

@@ -327,7 +327,7 @@ private ReturnTypeChain BuildReturnTypes()
         {
             if (Operation.LongRunning != null)
             {
-                return Operation.LongRunning.FinalResponse.BodyType;
+                return Operation.LongRunning.ReturnType;
             }
 
             var operationBodyTypes = Operation.Responses.Where(r => !r.IsErrorResponse).Select(r => r.BodyType).Distinct();

src/TypeSpec.Extension/Emitter.Csharp/src/lib/operation.ts

@@ -388,7 +388,11 @@ export function loadOperation(
         if (op.verb !== "delete") {
             const formattedType = getFormattedType(
                 program,
-                metadata.logicalResult
+                // TODO: we should check `logicalPath` or other ways to determine body type,
+                // after https://github.com/Azure/typespec-azure/issues/3725 is fixed
+                op.verb === "post"
+                    ? metadata.envelopeResult
+                    : metadata.logicalResult
             );
             bodyType = getInputType(context, formattedType, models, enums);
         }
@@ -401,7 +405,14 @@ export function loadOperation(
                 StatusCodes: op.verb === "delete" ? [204] : [200],
                 BodyType: bodyType,
                 BodyMediaType: BodyMediaType.Json
-            } as OperationResponse
+            } as OperationResponse,
+            ResultPath:
+                metadata.logicalPath ??
+                // https://github.com/Azure/typespec-azure/issues/3725
+                (metadata.envelopeResult != metadata.logicalResult &&
+                op.verb === "post"
+                    ? "result" // actually `result` is the only allowed path for now
+                    : undefined)
         } as OperationLongRunning;
     }
 }

src/TypeSpec.Extension/Emitter.Csharp/src/type/operationLongRunning.ts

@@ -7,4 +7,5 @@ import { OperationResponse } from "./operationResponse.js";
 export interface OperationLongRunning {
     FinalStateVia: OperationFinalStateVia;
     FinalResponse: OperationResponse;
+    ResultPath?: string;
 }

src/TypeSpec.Extension/Emitter.Csharp/test/TestProjects/lro/lro.tsp

@@ -47,5 +47,5 @@ model Pet {
 
 interface Projects {
     @doc("Creates a new pet or updates an existing one.")
-    createOrUpdate is LongRunningResourceCreateOrUpdate<Pet>;
+    createOrUpdate is LongRunningResourceCreateOrReplace<Pet>;
 }

src/TypeSpec.Extension/Emitter.Csharp/test/TestProjects/lro/src/Generated/tspCodeModel.json

@@ -11,7 +11,7 @@
    "Name": "Pet",
    "Namespace": "LroOperation",
    "IsNullable": false,
-   "Usage": "None",
+   "Usage": "RoundTrip",
    "Properties": [
     {
      "$id": "3",
@@ -143,62 +143,55 @@
       },
       {
        "$id": "19",
-       "Name": "contentType",
-       "NameInRequest": "Content-Type",
-       "Description": "This request has a JSON Merge Patch body.",
+       "Name": "resource",
+       "NameInRequest": "resource",
+       "Description": "The resource instance.",
        "Type": {
-        "$id": "20",
-        "Name": "Literal",
-        "LiteralValueType": {
-         "$id": "21",
-         "Name": "String",
-         "Kind": "String",
-         "IsNullable": false
-        },
-        "Value": "application/merge-patch+json",
-        "IsNullable": false
-       },
-       "Location": "Header",
-       "DefaultValue": {
-        "$id": "22",
-        "Type": {
-         "$ref": "20"
-        },
-        "Value": "application/merge-patch+json"
+        "$ref": "2"
        },
+       "Location": "Body",
        "IsRequired": true,
        "IsApiVersion": false,
        "IsResourceParameter": false,
-       "IsContentType": true,
+       "IsContentType": false,
        "IsEndpoint": false,
        "SkipUrlEncoding": false,
        "Explode": false,
-       "Kind": "Constant"
+       "Kind": "Method"
       },
       {
-       "$id": "23",
-       "Name": "resource",
-       "NameInRequest": "resource",
-       "Description": "The resource instance.",
+       "$id": "20",
+       "Name": "contentType",
+       "NameInRequest": "Content-Type",
        "Type": {
-        "$ref": "2"
+        "$id": "21",
+        "Name": "String",
+        "Kind": "String",
+        "IsNullable": false
        },
-       "Location": "Body",
-       "IsRequired": true,
+       "Location": "Header",
        "IsApiVersion": false,
        "IsResourceParameter": false,
-       "IsContentType": false,
+       "IsContentType": true,
+       "IsRequired": true,
        "IsEndpoint": false,
        "SkipUrlEncoding": false,
        "Explode": false,
-       "Kind": "Method"
+       "Kind": "Constant",
+       "DefaultValue": {
+        "$id": "22",
+        "Type": {
+         "$ref": "21"
+        },
+        "Value": "application/json"
+       }
       },
       {
-       "$id": "24",
+       "$id": "23",
        "Name": "accept",
        "NameInRequest": "Accept",
        "Type": {
-        "$id": "25",
+        "$id": "24",
         "Name": "String",
         "Kind": "String",
         "IsNullable": false
@@ -213,17 +206,17 @@
        "Explode": false,
        "Kind": "Constant",
        "DefaultValue": {
-        "$id": "26",
+        "$id": "25",
         "Type": {
-         "$ref": "25"
+         "$ref": "24"
         },
         "Value": "application/json"
        }
       }
      ],
      "Responses": [
       {
-       "$id": "27",
+       "$id": "26",
        "StatusCodes": [
         201
        ],
@@ -233,12 +226,12 @@
        "BodyMediaType": "Json",
        "Headers": [
         {
-         "$id": "28",
+         "$id": "27",
          "Name": "Operation-Location",
          "NameInResponse": "operationLocation",
          "Description": "The location for monitoring the operation state.",
          "Type": {
-          "$id": "29",
+          "$id": "28",
           "Name": "ResourceLocation",
           "Kind": "Uri",
           "IsNullable": false
@@ -248,7 +241,7 @@
        "IsErrorResponse": false
       },
       {
-       "$id": "30",
+       "$id": "29",
        "StatusCodes": [
         200
        ],
@@ -258,12 +251,12 @@
        "BodyMediaType": "Json",
        "Headers": [
         {
-         "$id": "31",
+         "$id": "30",
          "Name": "Operation-Location",
          "NameInResponse": "operationLocation",
          "Description": "The location for monitoring the operation state.",
          "Type": {
-          "$id": "32",
+          "$id": "31",
           "Name": "ResourceLocation",
           "Kind": "Uri",
           "IsNullable": false
@@ -273,19 +266,19 @@
        "IsErrorResponse": false
       }
      ],
-     "HttpMethod": "PATCH",
+     "HttpMethod": "PUT",
      "RequestBodyMediaType": "Json",
      "Uri": "{Endpoint}/language",
      "Path": "/authoring/analyze-text/Pet/{name}",
      "RequestMediaTypes": [
-      "application/merge-patch+json"
+      "application/json"
      ],
      "BufferResponse": true,
      "LongRunning": {
-      "$id": "33",
+      "$id": "32",
       "FinalStateVia": 3,
       "FinalResponse": {
-       "$id": "34",
+       "$id": "33",
        "StatusCodes": [
         200
        ],
@@ -296,11 +289,11 @@
       }
      },
      "GenerateProtocolMethod": true,
-     "GenerateConvenienceMethod": false
+     "GenerateConvenienceMethod": true
     }
    ],
    "Protocol": {
-    "$id": "35"
+    "$id": "34"
    },
    "Creatable": true
   }

test/CadlRanchProjects.Tests/lro/standard.cs

@@ -42,7 +42,10 @@ public Task Action() => Test(async (host) =>
         {
             var operation = await new StandardClient(host, null).ExportAsync(WaitUntil.Completed, "madge", "json");
             Assert.IsTrue(operation.HasCompleted);
-            // TODO: support model properties
+
+            var exportedUser = operation.Value;
+            Assert.AreEqual("madge", exportedUser.Name);
+            Assert.AreEqual("/users/madge", exportedUser.ResourceUri);
         });
     }
 }

test/CadlRanchProjects/azure/core/lro/standard/src/Generated/tspCodeModel.json

@@ -797,10 +797,11 @@
         200
        ],
        "BodyType": {
-        "$ref": "34"
+        "$ref": "14"
        },
        "BodyMediaType": "Json"
-      }
+      },
+      "ResultPath": "result"
      },
      "GenerateProtocolMethod": true,
      "GenerateConvenienceMethod": true