Bugfix: modern decorator support

Author: dpimonov

CHANGELOG.md

@@ -5,6 +5,13 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [7.2.1] - 2024-02-18
+
+### Fixed
+
+- TypeScript 5 decorators do not work.
+- Circular loop when using multiple inheritance through the decorator type options.
+
 ## [7.2.0] - 2023-10-18
 
 ### Added

README.md

@@ -183,6 +183,8 @@ TypeScript needs to run with the `experimentalDecorators` and `emitDecoratorMeta
 
 _If you want additional type-safety and reduced syntax you may wish to install [reflect-metadata](https://github.com/rbuckton/reflect-metadata). This step is on your choice and fully optional. When installed it must be available globally to work. This can usually be done with `import 'reflect-metadata';` in your main index file._
 
+Starting from TypeScript 5 we also support modern decorator syntax. However because parameter decorations with the modern syntax at the time of this writing are not supported - you will not be able to use `Inject` decorator provided by the library as well as `reflect-metadata` package when decide to use modern syntax. We are going to add support as soon as it will be provided to us by the TypeScript. If you need `Inject` decorator and enabling legacy decorators support is not an option - you can use declarative configuration.
+
 ## How it works?
 
 It defines configuration for each object which you are going to serialize or deserialize and uses this configuration to process data of your choice. There are two possible ways to define a configuration:

spec/property.spec.ts

@@ -1,5 +1,6 @@
-import { Property, TypeManager, TypeSerializer } from '../src';
+import { Property, Type, TypeManager, TypeSerializer } from '../src';
 
+@Type()
 class User
 {
     @Property() public name?: string;

spec/use-cases/complex-polymorphic-types.spec.ts

@@ -7,7 +7,7 @@ class Message
     @Property(() => Messageable) public reciever: Messageable
     @Property(String) public content: string
 
-    public constructor (content: string, sender: Messageable, reciever: Messageable) 
+    public constructor(content: string, sender: Messageable, reciever: Messageable) 
     {
         this.content = content;
         this.sender = sender;
@@ -22,7 +22,7 @@ class Status
 {
     @Property(String) status: string;
 
-    public constructor (status: string) 
+    public constructor(status: string) 
     {
         this.status = status;
 
@@ -31,6 +31,7 @@ class Status
 
 }
 
+@Type()
 abstract class Messageable
 {
     @Property(Array, [Message]) messages!: Message[];
@@ -56,7 +57,7 @@ class Chat extends Messageable implements HasTitle
 {
     @Property(String) title: string;
 
-    public constructor (title: string) 
+    public constructor(title: string) 
     {
         super();
 
@@ -75,7 +76,7 @@ class User extends Statusable implements Messageable, HasTitle
     @Property(String) title: string;
     @Property(Array, [Message]) messages!: Message[];
 
-    constructor (title: string) 
+    public constructor(title: string) 
     {
         super();
 

src/index.ts

@@ -22,6 +22,7 @@ export * from './generic-argument';
 export * from './generic-metadata-resolver';
 export * from './generic-metadata';
 export * from './generic-structure';
+export * from './inject-decorator';
 export * from './inject-index';
 export * from './inject-internals';
 export * from './inject-metadata';
@@ -33,6 +34,7 @@ export * from './log-level';
 export * from './log';
 export * from './metadata';
 export * from './naming-convention';
+export * from './property-decorator';
 export * from './property-extension-metadata-ctor-set-key';
 export * from './property-extension-metadata-ctor';
 export * from './property-extension-metadata';
@@ -58,6 +60,7 @@ export * from './type-configuration';
 export * from './type-context-entry';
 export * from './type-context';
 export * from './type-ctor';
+export * from './type-decorator';
 export * from './type-extension-metadata-ctor-set-key';
 export * from './type-extension-metadata-ctor';
 export * from './type-extension-metadata';
@@ -74,5 +77,6 @@ export * from './type-name';
 export * from './type-options-base';
 export * from './type-options';
 export * from './type-resolver';
+export * from './type-scope';
 export * from './type';
 export * from './unknown';

src/inject-decorator.ts

@@ -0,0 +1,6 @@
+/**
+ * Inject decorator.
+ * 
+ * @type {InjectDecorator}
+ */
+export type InjectDecorator = (target: any, propertyName: string | symbol | undefined, injectIndex: number) => void;

src/inject.ts

@@ -1,6 +1,7 @@
 import { isFunction, isNumber, isObject, isString, isUndefined } from 'lodash';
 import { isCtorFunction } from './functions/is-ctor-function';
 import { nameOf } from './functions/name-of';
+import { InjectDecorator } from './inject-decorator';
 import { InjectOptions } from './inject-options';
 import { TypeFn } from './type-fn';
 import { TypeManager } from './type-manager';
@@ -10,9 +11,9 @@ import { TypeManager } from './type-manager';
  * 
  * @param {TypeFn<TType>|InjectOptions<TType>|string} x Type function, inject options or parameter key from type context.
  * 
- * @returns {ParameterDecorator} Parameter decorator.
+ * @returns {InjectDecorator} Inject decorator.
  */
-export function Inject<TType>(x: TypeFn<TType> | InjectOptions<TType> | string): ParameterDecorator
+export function Inject<TType>(x: TypeFn<TType> | InjectOptions<TType> | string): InjectDecorator
 {
     const injectOptions = (isObject(x) ? x : {}) as InjectOptions<TType>;
 
@@ -25,8 +26,8 @@ export function Inject<TType>(x: TypeFn<TType> | InjectOptions<TType> | string):
     {
         injectOptions.typeFn = x as TypeFn<TType>;
     }
-
-    return function (target: any, propertyName: string | symbol, injectIndex: number): void
+    
+    return function (target: any, propertyName: string | symbol | undefined, injectIndex: number): void
     {
         if (!isCtorFunction(target))
         {

src/property-decorator.ts

@@ -0,0 +1,6 @@
+/**
+ * Property decorator.
+ * 
+ * @type {PropertyDecorator}
+ */
+export type PropertyDecorator = (target: any, context: any) => any;

src/property.ts

@@ -1,7 +1,8 @@
-import { isArray, isFunction, isObject, isString, isSymbol, merge } from 'lodash';
+import { isArray, isFunction, isObject, isString, isSymbol, isUndefined, merge } from 'lodash';
 import { isCtorFunction } from './functions/is-ctor-function';
 import { nameOf } from './functions/name-of';
 import { GenericArgument } from './generic-argument';
+import { PropertyDecorator } from './property-decorator';
 import { PropertyOptions } from './property-options';
 import { TypeArgument } from './type-argument';
 import { TypeFn } from './type-fn';
@@ -54,27 +55,71 @@ export function Property<TType>(
         propertyOptions.typeArgument = x;
     }
 
-    return function (target: any, propertyName: string | symbol): void
+    return function (target: any, context: any): any
     {
-        if (isCtorFunction(target))
+        // Modern decorator has a dynamic target which is dependent from where decorator 
+        // is applied (target), context as a second parameter (context) and optional 
+        // resolver like return type.
+        if (isObject(context) && context.hasOwnProperty('kind'))
         {
-            throw new Error(`${nameOf(target)}.${String(propertyName)}: property decorator cannot be applied to a static member.`);
-        }
+            const decoratorContext = context as any;
+            const kind = decoratorContext.kind;
+            const propertyName = decoratorContext.name;
 
-        if (isSymbol(propertyName))
-        {
-            throw new Error(`${nameOf(target.constructor)}.${String(propertyName)}: property decorator cannot be applied to a symbol.`);
+            if (kind === 'method' || kind === 'class')
+            {
+                throw new Error(`${String(propertyName)}: property decorator cannot be applied to a method or a class.`);
+            }
+
+            if (isUndefined(propertyName))
+            {
+                throw new Error(`${String(propertyName)}: property decorator cannot be applied to undefined values.`);
+            }
+
+            if (isSymbol(propertyName))
+            {
+                throw new Error(`${String(propertyName)}: property decorator cannot be applied to a symbol.`);
+            }
+
+            TypeManager.typeScope.addPropertyOptions(propertyName, propertyOptions);
+
+            return;
         }
 
-        if (isFunction(target[propertyName]))
+        // Legacy decorator has class reference as a first parameter (target), property name 
+        // or symbol as a second parameter (context) and no return type.
+        if (isObject(target) && (isString(context) || isSymbol(context)))
         {
-            throw new Error(`${nameOf(target.constructor)}.${String(propertyName)}: property decorator cannot be applied to a method.`);
-        }
+            const legacyTarget = target as any;
+            const propertyName = context as string | symbol | undefined;
+
+            if (isCtorFunction(legacyTarget))
+            {
+                throw new Error(`${nameOf(legacyTarget)}.${String(propertyName)}: property decorator cannot be applied to a static member.`);
+            }
 
-        const typeFn = target.constructor as TypeFn<any>;
-        
-        TypeManager.configureTypeMetadata(typeFn).configurePropertyMetadata(propertyName, propertyOptions);
+            if (isUndefined(propertyName))
+            {
+                throw new Error(`${nameOf(legacyTarget)}.${String(propertyName)}: property decorator cannot be applied to undefined values.`);
+            }
+
+            if (isSymbol(propertyName))
+            {
+                throw new Error(`${nameOf(legacyTarget.constructor)}.${String(propertyName)}: property decorator cannot be applied to a symbol.`);
+            }
+    
+            if (isFunction(legacyTarget[propertyName]))
+            {
+                throw new Error(`${nameOf(legacyTarget.constructor)}.${String(propertyName)}: property decorator cannot be applied to a method.`);
+            }
+    
+            const typeFn = legacyTarget.constructor as TypeFn<any>;
+            
+            TypeManager.configureTypeMetadata(typeFn).configurePropertyMetadata(propertyName, propertyOptions);
+    
+            return;
+        }
 
-        return;
+        throw new Error(`Property decorator was not able to detect correct resolver for the following target [${target}] and context [${context}].`);
     };
 }

src/type-decorator.ts

@@ -0,0 +1,6 @@
+/**
+ * Type decorator.
+ * 
+ * @type {TypeDecorator}
+ */
+export type TypeDecorator = (target: any, context?: any) => any;