Support string host param

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

@@ -10,7 +10,7 @@ import "@azure-tools/typespec-azure-core";
   "{sampleTypeSpecUrl}",
   "Endpoint Service",
   {
-    sampleTypeSpecUrl: string,
+    sampleTypeSpecUrl: url,
   }
 )
 @useAuth(ApiKeyAuth<ApiKeyLocation.header, "my-api-key">)

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

@@ -108,9 +108,10 @@ function fromSdkClient(
       const isEndpoint = parameter.name === endpointVariableName;
       const parameterType: InputType = isEndpoint
         ? {
-            kind: "url",
-            name: "url",
-            crossLanguageDefinitionId: "TypeSpec.url",
+            kind: parameter.type.kind === "string" ? "string" : "url",
+            name: "endpoint",
+            crossLanguageDefinitionId:
+              parameter.type.kind === "string" ? "TypeSpec.string" : "TypeSpec.url",
           }
         : fromSdkType(sdkContext, parameter.type); // TODO: consolidate with converter.fromSdkEndpointType
       parameters.push({
@@ -132,6 +133,7 @@ function fromSdkClient(
           parameter.clientDefaultValue,
           parameterType,
         ),
+        serverUrlTemplate: type.serverUrl,
       });
     }
     return parameters;

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

@@ -26,4 +26,5 @@ export interface InputParameter {
   arraySerializationDelimiter?: string;
   headerCollectionPrefix?: string;
   decorators?: DecoratorInfo[];
+  serverUrlTemplate?: string;
 }

packages/http-client-csharp/emitter/test/Unit/input-parameter.test.ts

@@ -626,11 +626,18 @@ describe("Test Cookie Parameters", () => {
       );
     });
   });
+});
 
-  describe("Unsupported endpoint url", () => {
-    it("cookie parameter is not supported", async () => {
-      const program = await typeSpecCompile(
-        `
+describe("Endpoint parameters", () => {
+  let runner: TestHost;
+
+  beforeEach(async () => {
+    runner = await createEmitterTestHost();
+  });
+
+  it("Multiple parameters are not supported", async () => {
+    const program = await typeSpecCompile(
+      `
               @service(#{
                 title: "Azure Csharp emitter Testing",
               })
@@ -645,23 +652,85 @@ describe("Test Cookie Parameters", () => {
 
               op test() : void;
         `,
-        runner,
-        { IsNamespaceNeeded: false },
-      );
-      const context = createEmitterContext(program);
-      const sdkContext = await createCSharpSdkContext(context);
-      const diagnostics = context.program.diagnostics;
-      createModel(sdkContext);
+      runner,
+      { IsNamespaceNeeded: false },
+    );
+    const context = createEmitterContext(program);
+    const sdkContext = await createCSharpSdkContext(context);
+    const diagnostics = context.program.diagnostics;
+    createModel(sdkContext);
 
-      const unsupportedCookie = diagnostics.find(
-        (d) => d.code === "@typespec/http-client-csharp/unsupported-endpoint-url",
-      );
-      ok(unsupportedCookie);
-      strictEqual(
-        unsupportedCookie.message,
-        "Unsupported server endpoint URL: https://{param1}{param2}/",
-      );
-    });
+    const unsupportedCookie = diagnostics.find(
+      (d) => d.code === "@typespec/http-client-csharp/unsupported-endpoint-url",
+    );
+    ok(unsupportedCookie);
+    strictEqual(
+      unsupportedCookie.message,
+      "Unsupported server endpoint URL: https://{param1}{param2}/",
+    );
+  });
+  it("String endpoint parameter has correct type", async () => {
+    const program = await typeSpecCompile(
+      `
+              @service(#{
+                title: "Azure Csharp emitter Testing",
+              })
+              @server(
+              "https://{param1}",
+              "Test endpoint",
+              {
+                param1: string,
+              })
+              namespace Test;
+
+              op test() : void;
+        `,
+      runner,
+      { IsNamespaceNeeded: false },
+    );
+    const context = createEmitterContext(program);
+    const sdkContext = await createCSharpSdkContext(context);
+    const codeModel = createModel(sdkContext);
+    const client = codeModel.clients[0];
+    ok(client);
+    ok(client.parameters);
+    const endpointParameter = client.parameters.find((p) => p.isEndpoint);
+    ok(endpointParameter);
+    strictEqual(endpointParameter.type.kind, "string");
+    strictEqual(endpointParameter.type.crossLanguageDefinitionId, "TypeSpec.string");
+    strictEqual(endpointParameter.serverUrlTemplate, "https://{param1}");
+  });
+
+  it("URL endpoint parameter has correct type", async () => {
+    const program = await typeSpecCompile(
+      `
+              @service(#{
+                title: "Azure Csharp emitter Testing",
+              })
+              @server(
+              "{param1}",
+              "Test endpoint",
+              {
+                param1: url,
+              })
+              namespace Test;
+
+              op test() : void;
+        `,
+      runner,
+      { IsNamespaceNeeded: false },
+    );
+    const context = createEmitterContext(program);
+    const sdkContext = await createCSharpSdkContext(context);
+    const codeModel = createModel(sdkContext);
+    const client = codeModel.clients[0];
+    ok(client);
+    ok(client.parameters);
+    const endpointParameter = client.parameters.find((p) => p.isEndpoint);
+    ok(endpointParameter);
+    strictEqual(endpointParameter.type.kind, "url");
+    strictEqual(endpointParameter.type.crossLanguageDefinitionId, "TypeSpec.url");
+    strictEqual(endpointParameter.serverUrlTemplate, "{param1}");
   });
 });
 

packages/http-client-csharp/generator/Microsoft.TypeSpec.Generator.ClientModel/src/Providers/ClientProvider.cs

@@ -255,6 +255,7 @@ private IReadOnlyList<ParameterProvider> GetClientParameters()
         }
 
         private Lazy<string?> _endpointParameterName;
+        private InputParameter? _inputEndpointParam;
         internal string? EndpointParameterName => _endpointParameterName.Value;
 
         private string? GetEndpointParameterName()
@@ -482,11 +483,22 @@ private MethodBodyStatement[] BuildPrimaryConstructorBody(IReadOnlyList<Paramete
             {
                 return [MethodBodyStatement.Empty];
             }
-
+            AssignmentExpression endpointAssignment;
+            if (_endpointParameter.Type.Equals(typeof(string)))
+            {
+                var serverTemplate = _inputEndpointParam!.ServerUrlTemplate;
+                endpointAssignment = EndpointField.Assign(
+                    New.Instance(typeof(Uri),
+                        new FormattableStringExpression(serverTemplate!, [_endpointParameter])));
+            }
+            else
+            {
+                endpointAssignment = EndpointField.Assign(_endpointParameter);
+            }
             List<MethodBodyStatement> body = [
                 ClientOptionsParameter.Assign(ClientOptionsParameter.InitializationValue!, nullCoalesce: true).Terminate(),
                 MethodBodyStatement.EmptyLine,
-                EndpointField.Assign(_endpointParameter).Terminate()
+                endpointAssignment.Terminate()
             ];
 
             // add other parameter assignments to their corresponding fields
@@ -643,14 +655,28 @@ protected override ScmMethodProvider[] BuildMethods()
 
         private ParameterProvider BuildClientEndpointParameter()
         {
-            var endpointParam = _inputClient.Parameters.FirstOrDefault(p => p.IsEndpoint);
-            if (endpointParam == null)
+            _inputEndpointParam = _inputClient.Parameters.FirstOrDefault(p => p.IsEndpoint);
+            if (_inputEndpointParam == null)
+            {
+                return KnownParameters.Endpoint;
+            }
+
+            var endpointParamType = ScmCodeModelGenerator.Instance.TypeFactory.CreateCSharpType(_inputEndpointParam.Type);
+            if (endpointParamType == null)
+            {
                 return KnownParameters.Endpoint;
+            }
 
-            ValueExpression? initializationValue = endpointParam.DefaultValue != null
-                ? New.Instance(KnownParameters.Endpoint.Type, Literal(endpointParam.DefaultValue.Value))
+            ValueExpression? initializationValue = _inputEndpointParam.DefaultValue != null
+                ? New.Instance(endpointParamType, Literal(_inputEndpointParam.DefaultValue.Value))
                 : null;
 
+            if (endpointParamType.Equals(typeof(string)) && _inputEndpointParam.ServerUrlTemplate != null)
+            {
+                return new(_inputEndpointParam);
+            }
+
+            // Must be a URI endpoint parameter
             return new(
                 KnownParameters.Endpoint.Name,
                 KnownParameters.Endpoint.Description,

packages/http-client-csharp/generator/Microsoft.TypeSpec.Generator.ClientModel/test/Providers/ClientProviders/ClientProviderTests.cs

@@ -12,7 +12,6 @@
 using Microsoft.TypeSpec.Generator.Input;
 using Microsoft.TypeSpec.Generator.Primitives;
 using Microsoft.TypeSpec.Generator.Providers;
-using Microsoft.TypeSpec.Generator.Snippets;
 using Microsoft.TypeSpec.Generator.Statements;
 using Microsoft.TypeSpec.Generator.Tests.Common;
 using NUnit.Framework;
@@ -960,6 +959,46 @@ public void XmlDocsAreWritten()
             Assert.AreEqual(Helpers.GetExpectedFromFile(), file.Content);
         }
 
+        [Test]
+        public void EndpointFieldAssignedFromUriParameter()
+        {
+            MockHelpers.LoadMockGenerator();
+            var client = InputFactory.Client(
+                TestClientName,
+                parameters: [InputFactory.Parameter(
+                    "endpoint",
+                    InputPrimitiveType.Url,
+                    isRequired: true,
+                    kind: InputParameterKind.Client,
+                    isEndpoint: true)]);
+            var clientProvider = new ClientProvider(client);
+            var constructor = clientProvider.Constructors.FirstOrDefault(
+                c => c.Signature.Initializer == null && c.Signature?.Modifiers == MethodSignatureModifiers.Public);
+
+            StringAssert.Contains("_endpoint = endpoint;", constructor?.BodyStatements?.ToDisplayString());
+        }
+
+        [TestCase("{endpoint}", "endpoint")]
+        [TestCase("https://{hostName}", "hostName")]
+        public void EndpointFieldAssignedFromStringParameter(string serverTemplate, string parameterName)
+        {
+            MockHelpers.LoadMockGenerator();
+            var client = InputFactory.Client(
+                TestClientName,
+                parameters: [InputFactory.Parameter(
+                    parameterName,
+                    InputPrimitiveType.String,
+                    isRequired: true,
+                    kind: InputParameterKind.Client,
+                    serverUrlTemplate: serverTemplate,
+                    isEndpoint: true)]);
+            var clientProvider = new ClientProvider(client);
+            var constructor = clientProvider.Constructors.FirstOrDefault(
+                c => c.Signature.Initializer == null && c.Signature?.Modifiers == MethodSignatureModifiers.Public);
+
+            StringAssert.Contains($"_endpoint = new global::System.Uri($\"{serverTemplate}\");", constructor?.BodyStatements?.ToDisplayString());
+        }
+
         private static InputClient GetEnumQueryParamClient()
         {
             return InputFactory.Client(

packages/http-client-csharp/generator/Microsoft.TypeSpec.Generator.Input/src/InputTypes/InputParameter.cs

@@ -25,7 +25,8 @@ public InputParameter(
             bool skipUrlEncoding,
             bool explode,
             string? arraySerializationDelimiter,
-            string? headerCollectionPrefix)
+            string? headerCollectionPrefix,
+            string? serverUrlTemplate)
         {
             Name = name;
             NameInRequest = nameInRequest;
@@ -43,6 +44,7 @@ public InputParameter(
             Explode = explode;
             ArraySerializationDelimiter = arraySerializationDelimiter;
             HeaderCollectionPrefix = headerCollectionPrefix;
+            ServerUrlTemplate = serverUrlTemplate;
         }
 
         public string Name { get; }
@@ -62,6 +64,7 @@ public InputParameter(
         public string? ArraySerializationDelimiter { get; }
         public string? HeaderCollectionPrefix { get; }
         public IReadOnlyList<InputDecoratorInfo> Decorators { get; internal set; } = new List<InputDecoratorInfo>();
+        public string? ServerUrlTemplate { get; }
 
         /// <summary>
         /// Update the instance with given parameters.

packages/http-client-csharp/generator/Microsoft.TypeSpec.Generator.Input/src/InputTypes/Serialization/InputParameterConverter.cs

@@ -44,6 +44,7 @@ public static InputParameter CreateInputParameter(ref Utf8JsonReader reader, str
             bool explode = false;
             string? arraySerializationDelimiter = null;
             string? headerCollectionPrefix = null;
+            string? serverUrlTemplate = null;
             IReadOnlyList<InputDecoratorInfo>? decorators = null;
             while (reader.TokenType != JsonTokenType.EndObject)
             {
@@ -64,6 +65,7 @@ public static InputParameter CreateInputParameter(ref Utf8JsonReader reader, str
                     || reader.TryReadBoolean("explode", ref explode)
                     || reader.TryReadString("arraySerializationDelimiter", ref arraySerializationDelimiter)
                     || reader.TryReadString("headerCollectionPrefix", ref headerCollectionPrefix)
+                    || reader.TryReadString("serverUrlTemplate", ref serverUrlTemplate)
                     || reader.TryReadComplexType("decorators", options, ref decorators);
 
                 if (!isKnownProperty)
@@ -109,7 +111,8 @@ public static InputParameter CreateInputParameter(ref Utf8JsonReader reader, str
                 skipUrlEncoding: skipUrlEncoding,
                 explode: explode,
                 arraySerializationDelimiter: arraySerializationDelimiter,
-                headerCollectionPrefix: headerCollectionPrefix)
+                headerCollectionPrefix: headerCollectionPrefix,
+                serverUrlTemplate: serverUrlTemplate)
             {
                 Decorators = decorators ?? []
             };

packages/http-client-csharp/generator/Microsoft.TypeSpec.Generator/test/common/InputFactory.cs

@@ -78,7 +78,8 @@ public static InputParameter Parameter(
             bool isContentType = false,
             bool isApiVersion = false,
             bool explode = false,
-            string? delimiter = null)
+            string? delimiter = null,
+            string? serverUrlTemplate = null)
         {
             return new InputParameter(
                 name,
@@ -96,7 +97,8 @@ public static InputParameter Parameter(
                 false,
                 explode,
                 delimiter,
-                null);
+                null,
+                serverUrlTemplate);
         }
 
         public static InputNamespace Namespace(

packages/http-client-csharp/generator/TestProjects/Local/Sample-TypeSpec/tspCodeModel.json

@@ -6807,7 +6807,7 @@
      "type": {
       "$id": "660",
       "kind": "url",
-      "name": "url",
+      "name": "endpoint",
       "crossLanguageDefinitionId": "TypeSpec.url"
      },
      "location": "Uri",
@@ -6817,7 +6817,8 @@
      "isEndpoint": true,
      "skipUrlEncoding": false,
      "explode": false,
-     "kind": "Client"
+     "kind": "Client",
+     "serverUrlTemplate": "{sampleTypeSpecUrl}"
     }
    ],
    "decorators": [],

packages/http-client-csharp/generator/TestProjects/Spector/http/authentication/api-key/tspCodeModel.json

@@ -198,7 +198,7 @@
      "type": {
       "$id": "21",
       "kind": "url",
-      "name": "url",
+      "name": "endpoint",
       "crossLanguageDefinitionId": "TypeSpec.url"
      },
      "location": "Uri",
@@ -218,7 +218,8 @@
        "crossLanguageDefinitionId": "TypeSpec.string"
       },
       "value": "http://localhost:3000"
-     }
+     },
+     "serverUrlTemplate": "{endpoint}"
     }
    ],
    "decorators": [],