[Multipart][TCGC] Support @multipartBody for bodyParam of `SdkHttpO…

…peration` (#1281)

supplement for PR #1090
- Support @multipartBody for `bodyParam` of `SdkHttpOperation`
- Only property of multipart body shall be added `multipartOptions` and
the property of base model shall have no `multipartOptions`

.chronus/changes/multipart-bodyparam-fix-2024-2024-7-1-15-10-38.md

@@ -0,0 +1,7 @@
+---
+changeKind: fix
+packages:
+  - "@azure-tools/typespec-client-generator-core"
+---
+
+Support @multipartBody for `bodyParam` of `SdkHttpOperation`

packages/typespec-client-generator-core/src/http.ts

@@ -127,7 +127,7 @@ function getSdkHttpParameters(
   const tspBody = httpOperation.parameters.body;
   // we add correspondingMethodParams after we create the type, since we need the info on the type
   const correspondingMethodParams: SdkModelPropertyType[] = [];
-  if (tspBody && tspBody?.bodyKind !== "multipart") {
+  if (tspBody) {
     // if there's a param on the body, we can just rely on getSdkHttpParameter
     if (tspBody.property && !isNeverOrVoidType(tspBody.property.type)) {
       const getParamResponse = diagnostics.pipe(

packages/typespec-client-generator-core/src/types.ts

@@ -1336,7 +1336,15 @@ export function getSdkModelPropertyType(
     flatten: shouldFlattenProperty(context, type),
   };
   if (operation) {
-    diagnostics.pipe(updateMultiPartInfo(context, type, result, operation));
+    const httpOperation = getHttpOperationWithCache(context, operation);
+    if (
+      type.model &&
+      httpOperation.parameters.body &&
+      httpOperation.parameters.body.type === type.model
+    ) {
+      // only add multipartOptions for property of multipart body
+      diagnostics.pipe(updateMultiPartInfo(context, type, result, operation));
+    }
   }
   return diagnostics.wrap(result);
 }

packages/typespec-client-generator-core/test/package.test.ts

@@ -3111,6 +3111,14 @@ describe("typespec-client-generator-core: package", () => {
       strictEqual(op.bodyParam.kind, "body");
       strictEqual(op.bodyParam.name, "testRequest");
       deepStrictEqual(op.bodyParam.correspondingMethodParams, [documentMethodParam]);
+
+      const anonymousModel = runner.context.sdkPackage.models[0];
+      strictEqual(anonymousModel.properties.length, 1);
+      strictEqual(anonymousModel.properties[0].kind, "property");
+      strictEqual(anonymousModel.properties[0].isMultipartFileInput, true);
+      ok(anonymousModel.properties[0].multipartOptions);
+      strictEqual(anonymousModel.properties[0].multipartOptions.isFilePart, true);
+      strictEqual(anonymousModel.properties[0].multipartOptions.isMulti, false);
     });
 
     it("anonymous model with @body should not be spread", async () => {

packages/typespec-client-generator-core/test/types/model-types.test.ts

@@ -1502,4 +1502,71 @@ describe("typespec-client-generator-core: model types", () => {
     ok(inputModel);
     strictEqual(inputModel.usage, UsageFlags.Input | UsageFlags.Xml);
   });
+
+  it("check bodyParam for @multipartBody", async function () {
+    await runner.compileWithBuiltInService(`
+        model Address {
+          city: string;
+        }
+        model MultiPartRequest{
+          id?: HttpPart<string>;
+          profileImage: HttpPart<bytes>;
+          address: HttpPart<Address>;
+          picture: HttpPart<File>;
+        }
+        @post
+        op upload(@header contentType: "multipart/form-data", @multipartBody body: MultiPartRequest): void;
+        `);
+    const formDataMethod = runner.context.sdkPackage.clients[0].methods[0];
+    strictEqual(formDataMethod.kind, "basic");
+    strictEqual(formDataMethod.name, "upload");
+    strictEqual(formDataMethod.parameters.length, 2);
+
+    strictEqual(formDataMethod.parameters[0].name, "contentType");
+    strictEqual(formDataMethod.parameters[0].type.kind, "constant");
+    strictEqual(formDataMethod.parameters[0].type.value, "multipart/form-data");
+
+    strictEqual(formDataMethod.parameters[1].name, "body");
+    strictEqual(formDataMethod.parameters[1].type.kind, "model");
+    strictEqual(formDataMethod.parameters[1].type.name, "MultiPartRequest");
+
+    const formDataOp = formDataMethod.operation;
+    strictEqual(formDataOp.parameters.length, 1);
+    ok(formDataOp.parameters.find((x) => x.name === "contentType" && x.kind === "header"));
+
+    const formDataBodyParam = formDataOp.bodyParam;
+    ok(formDataBodyParam);
+    strictEqual(formDataBodyParam.type.kind, "model");
+    strictEqual(formDataBodyParam.type.name, "MultiPartRequest");
+    strictEqual(formDataBodyParam.correspondingMethodParams.length, 1);
+    strictEqual(formDataBodyParam.type.properties.length, 4);
+    strictEqual(formDataBodyParam.type.properties[0].name, "id");
+    strictEqual(formDataBodyParam.type.properties[0].type.kind, "string");
+    strictEqual(formDataBodyParam.type.properties[1].name, "profileImage");
+    strictEqual(formDataBodyParam.type.properties[1].type.kind, "bytes");
+    strictEqual(formDataBodyParam.type.properties[2].name, "address");
+    strictEqual(formDataBodyParam.type.properties[2].type.kind, "model");
+    strictEqual(formDataBodyParam.type.properties[2].type.name, "Address");
+    strictEqual(formDataBodyParam.type.properties[3].name, "picture");
+    strictEqual(formDataBodyParam.type.properties[3].type.kind, "model");
+    strictEqual(formDataBodyParam.type.properties[3].type.name, "File");
+  });
+
+  it("check multipartOptions for property of base model", async function () {
+    await runner.compileWithBuiltInService(`
+      model MultiPartRequest{
+          fileProperty: HttpPart<File>;
+      }
+      @post
+      op upload(@header contentType: "multipart/form-data", @multipartBody body: MultiPartRequest): void;
+      `);
+    const models = runner.context.sdkPackage.models;
+    const fileModel = models.find((x) => x.name === "File");
+    ok(fileModel);
+    for (const p of fileModel.properties) {
+      strictEqual(p.kind, "property");
+      strictEqual(p.isMultipartFileInput, false);
+      strictEqual(p.multipartOptions, undefined);
+    }
+  });
 });