Update templates, docs, and sample

packages/samples/specs/resource-manager/resource-types/specific-extension/main.tsp

@@ -3,8 +3,6 @@ import "@typespec/versioning";
 import "@azure-tools/typespec-azure-core";
 import "@azure-tools/typespec-azure-resource-manager";
 
-using Http;
-using Rest;
 using Versioning;
 using Azure.Core;
 using Azure.ResourceManager;
@@ -82,24 +80,29 @@ interface EmplOps<Scope extends Azure.ResourceManager.Foundations.SimpleResource
 }
 
 /** Virtual resource for a virtual machine */
-alias VirtualMachine = Extension.ExternalResource<"Microsoft.Compute", "virtualMachines", "vmName">;
+alias VirtualMachine = Extension.ExternalResource<
+  "Microsoft.Compute",
+  "virtualMachines",
+  "vmName",
+  NamePattern = "^[a-zA-Z0-9][a-zA-Z0-9_.-]{0,80}$",
+  Description = "The name of the virtual machine"
+>;
 
 alias Scaleset = Extension.ExternalResource<
   "Microsoft.Compute",
   "virtualMachineScaleSets",
-  "scaleSetName"
+  "scaleSetName",
+  NamePattern = "^[a-zA-Z0-9][a-zA-Z0-9_.-]{0,80}$",
+  Description = "The name of the virtual machine scale set"
+>;
+
+alias VirtualMachineScaleSetVm = Extension.ExternalChildResource<
+  Scaleset,
+  "virtualMachineScaleSetVms",
+  "scaleSetVmName",
+  NamePattern = "^[a-zA-Z0-9][a-zA-Z0-9_.-]{0,80}$",
+  Description = "The name of the virtual machine scale set VM"
 >;
-/** A scaleset VM */
-@parentResource(Scaleset)
-model VirtualMachineScaleSetVm {
-  /** Name of the scaleset VM */
-  @visibility(Lifecycle.Read)
-  @path
-  @segment("virtualMachineScaleSetVms")
-  @key("scaleSetVmName")
-  @pattern("^[a-zA-Z0-9][a-zA-Z0-9_.-]{0,80}$")
-  name: string;
-}
 
 @armResourceOperations
 interface Employees extends EmplOps<Extension.ScopeParameter> {}

packages/samples/test/output/azure/resource-manager/resource-types/specific-extension/@azure-tools/typespec-autorest/2021-10-01-preview/openapi.json

@@ -1302,14 +1302,15 @@
           {
             "name": "scaleSetName",
             "in": "path",
-            "description": "The name of the virtual machine",
+            "description": "The name of the virtual machine scale set",
             "required": true,
-            "type": "string"
+            "type": "string",
+            "pattern": "^[a-zA-Z0-9][a-zA-Z0-9_.-]{0,80}$"
           },
           {
             "name": "scaleSetVmName",
             "in": "path",
-            "description": "Name of the scaleset VM",
+            "description": "The name of the virtual machine scale set VM",
             "required": true,
             "type": "string",
             "pattern": "^[a-zA-Z0-9][a-zA-Z0-9_.-]{0,80}$"
@@ -1354,14 +1355,15 @@
           {
             "name": "scaleSetName",
             "in": "path",
-            "description": "The name of the virtual machine",
+            "description": "The name of the virtual machine scale set",
             "required": true,
-            "type": "string"
+            "type": "string",
+            "pattern": "^[a-zA-Z0-9][a-zA-Z0-9_.-]{0,80}$"
           },
           {
             "name": "scaleSetVmName",
             "in": "path",
-            "description": "Name of the scaleset VM",
+            "description": "The name of the virtual machine scale set VM",
             "required": true,
             "type": "string",
             "pattern": "^[a-zA-Z0-9][a-zA-Z0-9_.-]{0,80}$"
@@ -1409,14 +1411,15 @@
           {
             "name": "scaleSetName",
             "in": "path",
-            "description": "The name of the virtual machine",
+            "description": "The name of the virtual machine scale set",
             "required": true,
-            "type": "string"
+            "type": "string",
+            "pattern": "^[a-zA-Z0-9][a-zA-Z0-9_.-]{0,80}$"
           },
           {
             "name": "scaleSetVmName",
             "in": "path",
-            "description": "Name of the scaleset VM",
+            "description": "The name of the virtual machine scale set VM",
             "required": true,
             "type": "string",
             "pattern": "^[a-zA-Z0-9][a-zA-Z0-9_.-]{0,80}$"
@@ -1494,14 +1497,15 @@
           {
             "name": "scaleSetName",
             "in": "path",
-            "description": "The name of the virtual machine",
+            "description": "The name of the virtual machine scale set",
             "required": true,
-            "type": "string"
+            "type": "string",
+            "pattern": "^[a-zA-Z0-9][a-zA-Z0-9_.-]{0,80}$"
           },
           {
             "name": "scaleSetVmName",
             "in": "path",
-            "description": "Name of the scaleset VM",
+            "description": "The name of the virtual machine scale set VM",
             "required": true,
             "type": "string",
             "pattern": "^[a-zA-Z0-9][a-zA-Z0-9_.-]{0,80}$"
@@ -1558,14 +1562,15 @@
           {
             "name": "scaleSetName",
             "in": "path",
-            "description": "The name of the virtual machine",
+            "description": "The name of the virtual machine scale set",
             "required": true,
-            "type": "string"
+            "type": "string",
+            "pattern": "^[a-zA-Z0-9][a-zA-Z0-9_.-]{0,80}$"
           },
           {
             "name": "scaleSetVmName",
             "in": "path",
-            "description": "Name of the scaleset VM",
+            "description": "The name of the virtual machine scale set VM",
             "required": true,
             "type": "string",
             "pattern": "^[a-zA-Z0-9][a-zA-Z0-9_.-]{0,80}$"
@@ -1630,14 +1635,15 @@
           {
             "name": "scaleSetName",
             "in": "path",
-            "description": "The name of the virtual machine",
+            "description": "The name of the virtual machine scale set",
             "required": true,
-            "type": "string"
+            "type": "string",
+            "pattern": "^[a-zA-Z0-9][a-zA-Z0-9_.-]{0,80}$"
           },
           {
             "name": "scaleSetVmName",
             "in": "path",
-            "description": "Name of the scaleset VM",
+            "description": "The name of the virtual machine scale set VM",
             "required": true,
             "type": "string",
             "pattern": "^[a-zA-Z0-9][a-zA-Z0-9_.-]{0,80}$"
@@ -1698,7 +1704,8 @@
             "in": "path",
             "description": "The name of the virtual machine",
             "required": true,
-            "type": "string"
+            "type": "string",
+            "pattern": "^[a-zA-Z0-9][a-zA-Z0-9_.-]{0,80}$"
           }
         ],
         "responses": {
@@ -1742,7 +1749,8 @@
             "in": "path",
             "description": "The name of the virtual machine",
             "required": true,
-            "type": "string"
+            "type": "string",
+            "pattern": "^[a-zA-Z0-9][a-zA-Z0-9_.-]{0,80}$"
           },
           {
             "name": "employeeName",
@@ -1789,7 +1797,8 @@
             "in": "path",
             "description": "The name of the virtual machine",
             "required": true,
-            "type": "string"
+            "type": "string",
+            "pattern": "^[a-zA-Z0-9][a-zA-Z0-9_.-]{0,80}$"
           },
           {
             "name": "employeeName",
@@ -1866,7 +1875,8 @@
             "in": "path",
             "description": "The name of the virtual machine",
             "required": true,
-            "type": "string"
+            "type": "string",
+            "pattern": "^[a-zA-Z0-9][a-zA-Z0-9_.-]{0,80}$"
           },
           {
             "name": "employeeName",
@@ -1922,7 +1932,8 @@
             "in": "path",
             "description": "The name of the virtual machine",
             "required": true,
-            "type": "string"
+            "type": "string",
+            "pattern": "^[a-zA-Z0-9][a-zA-Z0-9_.-]{0,80}$"
           },
           {
             "name": "employeeName",
@@ -1986,7 +1997,8 @@
             "in": "path",
             "description": "The name of the virtual machine",
             "required": true,
-            "type": "string"
+            "type": "string",
+            "pattern": "^[a-zA-Z0-9][a-zA-Z0-9_.-]{0,80}$"
           },
           {
             "name": "employeeName",
@@ -2506,21 +2518,6 @@
         ]
       },
       "readOnly": true
-    },
-    "VirtualMachineScaleSetVm": {
-      "type": "object",
-      "description": "A scaleset VM",
-      "properties": {
-        "name": {
-          "type": "string",
-          "description": "Name of the scaleset VM",
-          "pattern": "^[a-zA-Z0-9][a-zA-Z0-9_.-]{0,80}$",
-          "readOnly": true
-        }
-      },
-      "required": [
-        "name"
-      ]
     }
   },
   "parameters": {}

packages/typespec-azure-resource-manager/lib/extension/parameters.tsp

@@ -8,6 +8,7 @@ using Azure.ResourceManager.CommonTypes;
 
 /**
  * The default scope parameter for an extension resource.
+ * @template Type The type of the scope parameter (default is string). This can be used to specify `Azure.Core.armResourceIdentifier` type or other constrained type
  *
  * @example
  * ```typespec
@@ -17,11 +18,11 @@ using Azure.ResourceManager.CommonTypes;
  * ```
  */
 @builtInResource
-model ScopeParameter {
+model ScopeParameter<Type extends string = string> {
   @path(#{ allowReserved: true })
   @key
   @doc("The fully qualified Azure Resource manager identifier of the resource.")
-  scope: string;
+  scope: Type;
 }
 
 /**
@@ -124,6 +125,9 @@ model ManagementGroup<ParameterName extends valueof string = "managementGroupNam
  * @template TargetNamespace The provider namespace for the external resource.
  * @template ResourceType The type of the external resource.
  * @template ResourceParameterName The name of the 'name' parameter of the external resource.
+ * @template NamePattern The pattern restriction for the name of the external resource (default is none).
+ * @template NameType The type of the name parameter of the external resource (default is string).
+ * @template Description The description of the name parameter of the external resource (default is "The name of the resource").
  *
  * @example
  * ```typespec
@@ -138,35 +142,78 @@ model ManagementGroup<ParameterName extends valueof string = "managementGroupNam
  *   "virtualMachineScaleSets",
  *   "scaleSetName"
  * >;
- *
- * @parentResource(Scaleset)
- * model VirtualMachineScaleSetVm {
- *  @visibility(Lifecycle.Read)
- *  @path
- *  @segment("virtualMachineScaleSetVms")
- *  @key("scaleSetVmName")
- *  @pattern("^[a-zA-Z0-9][a-zA-Z0-9_.-]{0,80}$")
- *  @doc("Name of the scaleset VM")
- *  name: string;
- * }
- *
+
  * ```
  */
+@doc("")
 @armVirtualResource(TargetNamespace)
 @Http.Private.includeInapplicableMetadataInPayload(false)
 model ExternalResource<
   TargetNamespace extends valueof string,
   ResourceType extends valueof string,
-  ResourceParameterName extends valueof string
+  ResourceParameterName extends valueof string,
+  NamePattern extends valueof string = "",
+  NameType extends string = string,
+  Description extends valueof string = "The name of the resource"
 > {
-  /** The name of the virtual machine */
+  @doc(Description)
   @visibility(Lifecycle.Read)
   @path
   @key(ResourceParameterName)
   @segment(ResourceType)
-  name: string;
+  @pattern(NamePattern)
+  name: NameType;
 }
 
+/** An external child resource target, used when an extension targets a child resource from another provider namespace
+ * @template ParentModel The parent of this resource.
+ * @template ResourceType The type of this resource.
+ * @template ResourceParameterName The name of the 'name' parameter of this resource.
+ * @template NamePattern The pattern restriction for the name of this resource (default is none).
+ * @template NameType The type of the name parameter of this resource (default is string).
+ * @template Description The description of the name parameter of this resource (default is "The name of the resource").
+ *
+ * @example
+ * ```typespec
+ * alias VirtualMachine = ExternalResource<"Microsoft.Compute", "virtualMachines", "vmName">;
+ *
+ * ```
+ *
+ * @example
+ * ```typespec
+ * alias Scaleset = Extension.ExternalResource<
+ *   "Microsoft.Compute",
+ *   "virtualMachineScaleSets",
+ *   "scaleSetName"
+ * >;
+ *
+ * alias VirtualMachineScaleSetVm = Extension.ExternalChildResource<
+ *   Scaleset,
+ *   "virtualMachineScaleSetVms",
+ *   "scaleSetVmName"
+ * >;
+ *
+ * ```
+ */
+@doc("")
+@parentResource(ParentModel)
+@Http.Private.includeInapplicableMetadataInPayload(false)
+model ExternalChildResource<
+  ParentModel extends {},
+  ResourceType extends valueof string,
+  ResourceParameterName extends valueof string,
+  NamePattern extends valueof string = "",
+  NameType extends string = string,
+  Description extends valueof string = "The name of the resource"
+> {
+  @doc(Description)
+  @visibility(Lifecycle.Read)
+  @path
+  @key(ResourceParameterName)
+  @segment(ResourceType)
+  @pattern(NamePattern)
+  name: NameType;
+}
 /** A subscription target for an extension resource */
 @builtInSubscriptionResource
 model Subscription {}

packages/typespec-azure-resource-manager/src/private.decorators.ts

@@ -277,23 +277,10 @@ const $assignProviderNameValue: AssignProviderNameValueDecorator = (
   const { program } = context;
   const armProviderNamespace = getArmProviderNamespace(program, resourceType as Model);
   if (armProviderNamespace && target.type.kind === "String") {
-    target.type = createOrGetProviderType(program, armProviderNamespace);
+    target.type = $(program).literal.createString(armProviderNamespace);
   }
 };
 
-function createOrGetProviderType(program: Program, provider: string): StringLiteral {
-  const cache = ((program as ProviderNameCache)[PROVIDER_NAME_CACHE] ??= new Map<
-    string,
-    StringLiteral
-  >());
-  if (cache.has(provider)) {
-    return cache.get(provider)!;
-  }
-
-  const newType = $(program).realm.typekit.literal.createString(provider);
-  cache.set(provider, newType);
-  return newType;
-}
 /**
  * Update the ARM provider namespace for a given entity.
  * @param {DecoratorContext} context DecoratorContext