From 95268e17df0d1728e1db71fed63e9a248d2c0df3 Mon Sep 17 00:00:00 2001
From: Weidong Xu <weidxu@microsoft.com>
Date: Thu, 25 Jan 2024 12:50:00 +0800
Subject: [PATCH] mgmt, support flattenProperty (#2529)

---
 typespec-extension/changelog.md              |  1 +
 typespec-extension/src/code-model-builder.ts | 12 ++++++++----
 2 files changed, 9 insertions(+), 4 deletions(-)

diff --git a/typespec-extension/changelog.md b/typespec-extension/changelog.md
index 4e2f06e5b7..96c6aab678 100644
--- a/typespec-extension/changelog.md
+++ b/typespec-extension/changelog.md
@@ -5,6 +5,7 @@
 Compatible with compiler 0.52.
 
 - Supported `@clientName` from "@azure-tools/typespec-client-generator-core".
+- Supported `@flattenProperty` from "@azure-tools/typespec-client-generator-core".
 
 ## 0.12.3 (2024-01-22)
 
diff --git a/typespec-extension/src/code-model-builder.ts b/typespec-extension/src/code-model-builder.ts
index 70b7218d2b..e35ea1ad93 100644
--- a/typespec-extension/src/code-model-builder.ts
+++ b/typespec-extension/src/code-model-builder.ts
@@ -72,6 +72,7 @@ import {
   SdkClient,
   getCrossLanguageDefinitionId,
   getClientNameOverride,
+  shouldFlattenProperty,
 } from "@azure-tools/typespec-client-generator-core";
 import { fail } from "assert";
 import {
@@ -2277,14 +2278,17 @@ export class CodeModelBuilder {
     const schema = this.processSchema(prop, prop.name);
     let nullable = isNullableType(prop.type);
 
-    let extensions = undefined;
+    let extensions: Record<string, any> | undefined = undefined;
     if (this.isSecret(prop)) {
-      extensions = {
-        "x-ms-secret": true,
-      };
+      extensions = extensions ?? {};
+      extensions["x-ms-secret"] = true;
       // if the property does not return in response, it had to be nullable
       nullable = true;
     }
+    if (shouldFlattenProperty(this.sdkContext, prop)) {
+      extensions = extensions ?? {};
+      extensions["x-ms-client-flatten"] = true;
+    }
 
     return new Property(this.getName(prop), this.getDoc(prop), schema, {
       summary: this.getSummary(prop),