Backmerge release/may-2026 (tcgc@0.68.2 hotfix) (#4489)

Backmerge of hotfix release tcgc@0.69.0 from `release/may-2026` into
`main`.

This ensures the version bump and fixes are reflected in main.

⚠️ **Rebase merge** this PR (do not squash).

---------

Co-authored-by: Copilot <198982749+Copilot@users.noreply.github.com>
Co-authored-by: tadelesh <1726438+tadelesh@users.noreply.github.com>
Co-authored-by: tadelesh <chenjieshi@microsoft.com>
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: 4 people

packages/typespec-client-generator-core/CHANGELOG.md

@@ -1,5 +1,18 @@
 # Change Log - @azure-tools/typespec-client-generator-core
 
+## 0.68.2
+
+### Features
+
+- [#4480](https://github.com/Azure/typespec-azure/pull/4480) Extend `isExactName` to additional SDK types whose names can be changed by `@clientName`: `SdkClientType`, `SdkServiceMethodBase` (and its derived method kinds), and `SdkEnumValueType`. Also fixed `SdkClientType.name` to strip the internal `exact()` marker.
+
+### Bug Fixes
+
+- [#4477](https://github.com/Azure/typespec-azure/pull/4477) Fix `reorderParameters`, `addParameter`, `removeParameter`, and `replaceParameter` so that decorators copied to cloned model properties and cloned operations are applied (by calling `finishType` after cloning). This fixes scenarios such as parameters with `@typeChangedFrom` under a `@versioned` service.
+- [#4487](https://github.com/Azure/typespec-azure/pull/4487) Fix example value matching for `decimal` and `decimal128` typed properties. JSON `number` values in example files are now correctly recognized as matching `decimal` / `decimal128` typed properties.
+- [#4484](https://github.com/Azure/typespec-azure/pull/4484) Fix example values being dropped on subtypes added via `@hierarchyBuilding` by propagating serialization options from the nearest ancestor to the newly added subtype
+
+
 ## 0.68.1
 
 ### Bug Fixes

packages/typespec-client-generator-core/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@azure-tools/typespec-client-generator-core",
-  "version": "0.68.1",
+  "version": "0.68.2",
   "author": "Microsoft Corporation",
   "description": "TypeSpec Data Plane Generation library",
   "homepage": "https://azure.github.io/typespec-azure",

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

@@ -33,7 +33,7 @@ import {
 } from "./internal-utils.js";
 import { createDiagnostic } from "./lib.js";
 import { createSdkMethods, getSdkMethodParameter } from "./methods.js";
-import { getCrossLanguageDefinitionId } from "./public-utils.js";
+import { getCrossLanguageDefinitionId, getLibraryName, isExactClientName } from "./public-utils.js";
 import { getSdkBuiltInType, getSdkCredentialParameter, getTypeSpecBuiltInType } from "./types.js";
 
 function getEndpointTypeFromSingleServer<
@@ -190,17 +190,15 @@ export function createSdkClientType<TServiceOperation extends SdkServiceOperatio
 ): [SdkClientType<TServiceOperation>, readonly Diagnostic[]] {
   const diagnostics = createDiagnosticCollector();
   let name = client.name;
-  if (client.type) {
-    const override = getClientNameOverride(context, client.type);
-    if (override) {
-      name = override;
-    }
+  if (client.type && getClientNameOverride(context, client.type)) {
+    name = getLibraryName(context, client.type);
   }
   const clientType = getActualClientType(client);
   const sdkClientType: SdkClientType<TServiceOperation> = {
     __raw: client,
     kind: "client",
     name,
+    isExactName: client.type ? isExactClientName(context, client.type) : false,
     doc: client.type ? getClientDoc(context, client.type) : undefined,
     summary: client.type ? getSummary(context.program, client.type) : undefined,
     methods: [],

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

@@ -31,6 +31,7 @@ import {
   SdkServiceOperation,
   SdkType,
   TCGCContext,
+  isSdkFixedPointKind,
   isSdkFloatKind,
   isSdkIntKind,
 } from "./interfaces.js";
@@ -446,7 +447,7 @@ function getSdkTypeExample(
     return diagnostics.wrap(undefined);
   }
 
-  if (isSdkIntKind(type.kind) || isSdkFloatKind(type.kind)) {
+  if (isSdkIntKind(type.kind) || isSdkFloatKind(type.kind) || isSdkFixedPointKind(type.kind)) {
     return getSdkBaseTypeExample("number", type as SdkType, example, relativePath);
   } else {
     switch (type.kind) {

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

@@ -20,6 +20,8 @@ function cloneOperation(
   // Copy decorators from the original operation
   if (operation.decorators) {
     newOp.decorators = [...operation.decorators];
+    // Re-finish the type so the copied decorators are applied
+    tk.type.finishType(newOp);
   }
 
   // Set the source operation for tracing
@@ -40,6 +42,8 @@ function cloneModelProperty(tk: ReturnType<typeof $>, prop: ModelProperty): Mode
   if (prop.decorators) {
     clonedProp.decorators = [...prop.decorators];
   }
+  // Finish the type so decorators are applied
+  tk.type.finishType(clonedProp);
   return clonedProp;
 }
 

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

@@ -208,6 +208,8 @@ export interface SdkClientType<
   kind: "client";
   /** Name of the client. */
   name: string;
+  /** Whether name should be used exactly as-is, without casing transformations. */
+  isExactName: boolean;
   /** Full qualified namespace. */
   namespace: string;
   /** Document for the type. */
@@ -373,7 +375,7 @@ export function isSdkFloatKind(kind: string): kind is keyof typeof SdkFloatingPo
   return kind in SdkFloatingPointKindsEnum;
 }
 
-function isSdkFixedPointKind(kind: string): kind is keyof typeof SdkFixedPointKindsEnum {
+export function isSdkFixedPointKind(kind: string): kind is keyof typeof SdkFixedPointKindsEnum {
   return kind in SdkFixedPointKindsEnum;
 }
 
@@ -480,6 +482,8 @@ export interface SdkEnumValueType<
 > extends SdkTypeBase {
   kind: "enumvalue";
   name: string;
+  /** Whether name should be used exactly as-is, without casing transformations. */
+  isExactName: boolean;
   value: string | number;
   enumType: SdkEnumType;
   valueType: TValueType;
@@ -1000,6 +1004,8 @@ interface SdkServiceMethodBase<
 > extends DecoratedType {
   __raw?: Operation;
   name: string;
+  /** Whether name should be used exactly as-is, without casing transformations. */
+  isExactName: boolean;
   /** Whether the type has public or private accessibility */
   access: AccessFlags;
   /** API versions supported for current type. */

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

@@ -80,6 +80,7 @@ import {
   getCrossLanguageDefinitionId,
   getHttpOperationWithCache,
   getLibraryName,
+  isExactClientName,
 } from "./public-utils.js";
 import {
   getClientTypeWithDiagnostics,
@@ -736,6 +737,7 @@ export function getSdkBasicServiceMethod<TServiceOperation extends SdkServiceOpe
     __raw: operation,
     kind: "basic",
     name,
+    isExactName: isExactClientName(context, operation),
     access: getAccess(context, operation) ?? "public",
     parameters: methodParameters,
     doc: getClientDoc(context, operation),

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

@@ -1018,6 +1018,7 @@ function getSdkEnumValueWithDiagnostics(
   return diagnostics.wrap({
     ...diagnostics.pipe(getSdkTypeBaseHelper(context, type, "enumvalue")),
     name: getLibraryName(context, type),
+    isExactName: isExactClientName(context, type),
     value: type.value ?? type.name,
     enumType,
     valueType: enumType.valueType,
@@ -1081,6 +1082,7 @@ function getSdkUnionEnumValues(
     values.push({
       ...diagnostics.pipe(getSdkTypeBaseHelper(context, member.type, "enumvalue")),
       name: name ? name : `${member.value}`,
+      isExactName: isExactClientName(context, member.type),
       value: member.value,
       valueType: enumType.valueType,
       enumType,
@@ -2110,6 +2112,11 @@ function handleLegacyHierarchyBuilding(context: TCGCContext): [void, readonly Di
         currBaseModel = currBaseModel.baseModel;
       }
 
+      // Propagate serialization options to the newly added subtype.
+      // This is needed because updateSerializationOptions may have already run
+      // on the parent model before this subtype was added to discriminatedSubtypes.
+      propagateSerializationToSubtype(context, sdkType);
+
       // Filter out legacy hierarchy building properties
       sdkType.properties = sdkType.properties.filter((property) => {
         return (
@@ -2121,6 +2128,31 @@ function handleLegacyHierarchyBuilding(context: TCGCContext): [void, readonly Di
   return diagnostics.wrap(undefined);
 }
 
+/**
+ * Propagate serialization options from a parent model to a newly added subtype.
+ * This handles the case where updateSerializationOptions already ran on the parent
+ * before the subtype was added via @hierarchyBuilding.
+ */
+function propagateSerializationToSubtype(context: TCGCContext, sdkType: SdkModelType): void {
+  // Find the nearest ancestor with serialization options to determine content types
+  let ancestor: SdkModelType | undefined = sdkType.baseModel;
+  const contentTypes: string[] = [];
+  while (ancestor) {
+    if (ancestor.serializationOptions.json) {
+      contentTypes.push("application/json");
+    }
+    if (ancestor.serializationOptions.xml) {
+      contentTypes.push("application/xml");
+    }
+    if (contentTypes.length > 0) break;
+    ancestor = ancestor.baseModel;
+  }
+
+  if (contentTypes.length > 0) {
+    updateSerializationOptions(context, sdkType, contentTypes);
+  }
+}
+
 /**
  * Reconcile properties on a rebased model after `@hierarchyBuilding(oldBase, newBase)`.
  *

packages/typespec-client-generator-core/test/examples/example-types/getDecimal.json

@@ -0,0 +1,10 @@
+{
+  "operationId": "getDecimal",
+  "title": "getDecimal",
+  "parameters": {},
+  "responses": {
+    "200": {
+      "body": 123.45
+    }
+  }
+}

packages/typespec-client-generator-core/test/examples/example-types/getDecimal128.json

@@ -0,0 +1,10 @@
+{
+  "operationId": "getDecimal128",
+  "title": "getDecimal128",
+  "parameters": {},
+  "responses": {
+    "200": {
+      "body": 80
+    }
+  }
+}