[tcgc] change generic decorator list data structure to support duplicate decorator use case

.chronus/changes/fix_decorator_list-2024-5-26-13-53-0.md

@@ -0,0 +1,7 @@
+---
+changeKind: internal
+packages:
+  - "@azure-tools/typespec-client-generator-core"
+---
+
+change generic decorator list data structure to support duplicate decorator use case

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

@@ -1,4 +1,5 @@
 export const defaultDecoratorsAllowList = [
   "TypeSpec\\.Xml\\..*",
   "Azure\\.Core\\.@useFinalStateVia",
+  "Autorest\\.@example",
 ];

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

@@ -235,7 +235,7 @@ function createContentTypeOrAcceptHeader(
   let type: SdkType = {
     kind: "string",
     encode: "string",
-    decorators: {},
+    decorators: [],
   };
   // for contentType, we treat it as a constant IFF there's one value and it's application/json.
   // this is to prevent a breaking change when a service adds more content types in the future.
@@ -256,7 +256,7 @@ function createContentTypeOrAcceptHeader(
       valueType: type,
       name: `${httpOperation.operation.name}ContentType`,
       isGeneratedName: true,
-      decorators: {},
+      decorators: [],
     };
   }
   // No need for clientDefaultValue because it's a constant, it only has one value
@@ -269,7 +269,7 @@ function createContentTypeOrAcceptHeader(
     onClient: false,
     optional: false,
     crossLanguageDefinitionId: `${getCrossLanguageDefinitionId(context, httpOperation.operation)}.${name}`,
-    decorators: {},
+    decorators: [],
   };
 }
 

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

@@ -78,12 +78,17 @@ export interface SdkOperationGroup {
 }
 
 interface DecoratedType {
-  // Client types sourced from TypeSpec decorated types will have this generic decoratores dict.
-  // The key is the fully qualified name of the decorator. For example, `TypeSpec.@encode`, `TypeSpec.Xml.@attribute`.
-  // The value is a dict of the decorator's arguments' value (key is argument's name).
-  // Only decorators in allowed list will be included in this dict.
+  // Client types sourced from TypeSpec decorated types will have this generic decoratores list.
+  // Only decorators in allowed list will be included in this list.
   // Language's emitter could set `additionalDecorators` in the option when `createSdkContext` to extend the allowed list.
-  decorators: Record<string, Record<string, any>>;
+  decorators: DecoratorInfo[];
+}
+
+export interface DecoratorInfo {
+  // Fully qualified name of the decorator. For example, `TypeSpec.@encode`, `TypeSpec.Xml.@attribute`.
+  name: string;
+  // A dict of the decorator's arguments. For example, `{ encoding: "base64url" }`.
+  arguments: Record<string, any>;
 }
 
 interface SdkTypeBase extends DecoratedType {

packages/typespec-client-generator-core/src/internal-utils.ts

@@ -25,6 +25,7 @@ import {
 import { HttpOperation, HttpStatusCodeRange } from "@typespec/http";
 import { getAddedOnVersions, getRemovedOnVersions, getVersions } from "@typespec/versioning";
 import {
+  DecoratorInfo,
   SdkBuiltInKinds,
   SdkBuiltInType,
   SdkClient,
@@ -244,7 +245,7 @@ interface DefaultSdkTypeBase<TKind> {
   __raw: Type;
   deprecation?: string;
   kind: TKind;
-  decorators: Record<string, Record<string, any>>;
+  decorators: DecoratorInfo[];
 }
 
 /**
@@ -272,9 +273,9 @@ export function getNamespacePrefix(namespace: Namespace): string {
 export function getTypeDecorators(
   context: TCGCContext,
   type: Type
-): [Record<string, Record<string, any>>, readonly Diagnostic[]] {
+): [DecoratorInfo[], readonly Diagnostic[]] {
   const diagnostics = createDiagnosticCollector();
-  const retval: Record<string, Record<string, any>> = {};
+  const retval: DecoratorInfo[] = [];
   if ("decorators" in type) {
     for (const decorator of type.decorators) {
       // only process explicitly defined decorators
@@ -288,12 +289,16 @@ export function getTypeDecorators(
           continue;
         }
 
-        retval[decoratorName] = {};
+        const decoratorInfo: DecoratorInfo = {
+          name: decoratorName,
+          arguments: {},
+        };
         for (let i = 0; i < decorator.args.length; i++) {
-          retval[decoratorName][decorator.definition.parameters[i].name] = diagnostics.pipe(
+          decoratorInfo.arguments[decorator.definition.parameters[i].name] = diagnostics.pipe(
             getDecoratorArgValue(decorator.args[i].jsValue, type, decoratorName)
           );
         }
+        retval.push(decoratorInfo);
       }
     }
   }

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

@@ -215,7 +215,7 @@ function getSdkMethodResponse<
       name: createGeneratedName(context, operation, "UnionResponse"),
       isGeneratedName: true,
       crossLanguageDefinitionId: getCrossLanguageDefinitionId(context, operation),
-      decorators: {},
+      decorators: [],
     };
   } else if (responseTypes) {
     type = allResponseBodies[0];
@@ -224,7 +224,7 @@ function getSdkMethodResponse<
     type = {
       kind: "nullable",
       type: type,
-      decorators: {},
+      decorators: [],
     };
   }
   return {
@@ -396,7 +396,7 @@ function getSdkInitializationType<
     apiVersions: context.__tspTypeToApiVersions.get(client.type)!,
     isFormDataType: false,
     isError: false,
-    decorators: {},
+    decorators: [],
   });
 }
 
@@ -460,7 +460,7 @@ function getSdkMethods<TOptions extends object, TServiceOperation extends SdkSer
       response: operationGroupClient,
       apiVersions: getAvailableApiVersions(context, operationGroup.type, client.type),
       crossLanguageDefintionId: getCrossLanguageDefinitionId(context, operationGroup.type),
-      decorators: {},
+      decorators: [],
     });
   }
   return diagnostics.wrap(retval);
@@ -495,15 +495,15 @@ function getSdkEndpointParameter(
           type: {
             kind: "string",
             encode: "string",
-            decorators: {},
+            decorators: [],
           },
           isApiVersionParam: false,
           apiVersions: context.__tspTypeToApiVersions.get(client.type)!,
           crossLanguageDefinitionId: `${getCrossLanguageDefinitionId(context, client.service)}.endpoint`,
-          decorators: {},
+          decorators: [],
         },
       ],
-      decorators: {},
+      decorators: [],
     };
   } else {
     // this means we have one server
@@ -512,7 +512,7 @@ function getSdkEndpointParameter(
       kind: "endpoint",
       serverUrl: servers[0].url,
       templateArguments,
-      decorators: {},
+      decorators: [],
     };
     for (const param of servers[0].parameters.values()) {
       const sdkParam = diagnostics.pipe(getSdkHttpParameter(context, param, undefined, "path"));
@@ -551,7 +551,7 @@ function getSdkEndpointParameter(
     optional,
     isApiVersionParam: false,
     crossLanguageDefinitionId: `${getCrossLanguageDefinitionId(context, client.service)}.endpoint`,
-    decorators: {},
+    decorators: [],
   });
 }
 

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

@@ -503,7 +503,7 @@ function addDiscriminatorToModelType(
       discriminatorType = {
         kind: "string",
         encode: "string",
-        decorators: {},
+        decorators: [],
       };
     }
     const name = discriminatorProperty ? discriminatorProperty.name : discriminator.propertyName;
@@ -526,7 +526,7 @@ function addDiscriminatorToModelType(
       isMultipartFileInput: false, // discriminator property cannot be a file
       flatten: false, // discriminator properties can not be flattened
       crossLanguageDefinitionId: `${model.crossLanguageDefinitionId}.${name}`,
-      decorators: {},
+      decorators: [],
     });
     model.discriminatorProperty = model.properties[0];
   }
@@ -984,7 +984,7 @@ function getSdkCredentialType(
         __raw: client.service,
         kind: "credential",
         scheme: scheme,
-        decorators: {},
+        decorators: [],
       });
     }
   }
@@ -996,7 +996,7 @@ function getSdkCredentialType(
       name: createGeneratedName(context, client.service, "CredentialUnion"),
       isGeneratedName: true,
       crossLanguageDefinitionId: getCrossLanguageDefinitionId(context, client.service),
-      decorators: {},
+      decorators: [],
     };
   }
   return credentialTypes[0];
@@ -1020,7 +1020,7 @@ export function getSdkCredentialParameter(
     optional: false,
     isApiVersionParam: false,
     crossLanguageDefinitionId: `${getCrossLanguageDefinitionId(context, client.service)}.credential`,
-    decorators: {},
+    decorators: [],
   };
 }