feat: Add decorator factories and refactor into @loopback/metadata

.prettierignore

@@ -4,3 +4,4 @@ packages/*/api-docs
 packages/cli/generators/*/templates
 package.json
 packages/*/package.json
+*.md

packages/authentication/src/decorators/authenticate.ts

@@ -3,7 +3,11 @@
 // This file is licensed under the MIT License.
 // License text available at https://opensource.org/licenses/MIT
 
-import {Reflector, Constructor} from '@loopback/context';
+import {
+  MetadataInspector,
+  Constructor,
+  MethodDecoratorFactory,
+} from '@loopback/context';
 import {AuthenticationBindings} from '../keys';
 
 /**
@@ -21,18 +25,13 @@ export interface AuthenticationMetadata {
  * @param options Additional options to configure the authentication.
  */
 export function authenticate(strategyName: string, options?: Object) {
-  return function(controllerClass: Object, methodName: string) {
-    const metadataObj: AuthenticationMetadata = {
+  return MethodDecoratorFactory.createDecorator<AuthenticationMetadata>(
+    AuthenticationBindings.METADATA,
+    {
       strategy: strategyName,
       options: options || {},
-    };
-    Reflector.defineMetadata(
-      AuthenticationBindings.METADATA,
-      metadataObj,
-      controllerClass,
-      methodName,
-    );
-  };
+    },
+  );
 }
 
 /**
@@ -45,7 +44,7 @@ export function getAuthenticateMetadata(
   controllerClass: Constructor<{}>,
   methodName: string,
 ): AuthenticationMetadata | undefined {
-  return Reflector.getMetadata(
+  return MetadataInspector.getMethodMetadata<AuthenticationMetadata>(
     AuthenticationBindings.METADATA,
     controllerClass.prototype,
     methodName,

packages/context/package.json

@@ -22,7 +22,7 @@
   "author": "IBM",
   "license": "MIT",
   "dependencies": {
-    "reflect-metadata": "^0.1.10"
+    "@loopback/metadata": "^4.0.0-alpha.1"
   },
   "devDependencies": {
     "@loopback/build": "^4.0.0-alpha.7",

packages/context/src/index.ts

@@ -14,7 +14,6 @@ export {
 export {Context} from './context';
 export {Constructor} from './resolver';
 export {inject, Setter, Getter} from './inject';
-export {NamespacedReflect} from './reflect';
 export {Provider} from './provider';
 export {isPromise} from './is-promise';
 
@@ -25,4 +24,5 @@ export {
   describeInjectedProperties,
   Injection,
 } from './inject';
-export {Reflector} from './reflect';
+
+export * from '@loopback/metadata';

packages/context/src/inject.ts

@@ -3,7 +3,12 @@
 // This file is licensed under the MIT License.
 // License text available at https://opensource.org/licenses/MIT
 
-import {Reflector} from './reflect';
+import {
+  MetadataInspector,
+  ParameterDecoratorFactory,
+  PropertyDecoratorFactory,
+  MetadataMap,
+} from '@loopback/metadata';
 import {BoundValue, ValueOrPromise} from './binding';
 import {Context} from './context';
 
@@ -60,42 +65,51 @@ export function inject(
   return function markParameterOrPropertyAsInjected(
     // tslint:disable-next-line:no-any
     target: any,
-    propertyKey?: string | symbol,
-    propertyDescriptorOrParameterIndex?:
+    propertyKey: string | symbol,
+    methodDescriptorOrParameterIndex?:
       | TypedPropertyDescriptor<BoundValue>
       | number,
   ) {
-    if (typeof propertyDescriptorOrParameterIndex === 'number') {
+    if (typeof methodDescriptorOrParameterIndex === 'number') {
       // The decorator is applied to a method parameter
       // Please note propertyKey is `undefined` for constructor
-      const injectedArgs: Injection[] =
-        Reflector.getOwnMetadata(PARAMETERS_KEY, target, propertyKey!) || [];
-      injectedArgs[propertyDescriptorOrParameterIndex] = {
-        bindingKey,
-        metadata,
-        resolve,
-      };
-      Reflector.defineMetadata(
+      const paramDecorator: ParameterDecorator = ParameterDecoratorFactory.createDecorator(
         PARAMETERS_KEY,
-        injectedArgs,
-        target,
-        propertyKey!,
+        {
+          bindingKey,
+          metadata,
+          resolve,
+        },
       );
+      paramDecorator(target, propertyKey!, methodDescriptorOrParameterIndex);
     } else if (propertyKey) {
+      // Property or method
       if (typeof Object.getPrototypeOf(target) === 'function') {
         const prop = target.name + '.' + propertyKey.toString();
         throw new Error(
           '@inject is not supported for a static property: ' + prop,
         );
       }
-      // The decorator is applied to a property
-      const injections: {[p: string]: Injection} =
-        Reflector.getOwnMetadata(PROPERTIES_KEY, target) || {};
-      injections[propertyKey] = {bindingKey, metadata, resolve};
-      Reflector.defineMetadata(PROPERTIES_KEY, injections, target);
+      if (methodDescriptorOrParameterIndex) {
+        // Method
+        throw new Error(
+          '@inject cannot be used on a method: ' + propertyKey.toString(),
+        );
+      }
+      const propDecorator: PropertyDecorator = PropertyDecoratorFactory.createDecorator(
+        PROPERTIES_KEY,
+        {
+          bindingKey,
+          metadata,
+          resolve,
+        },
+      );
+      propDecorator(target, propertyKey!);
     } else {
+      // It won't happen here as `@inject` is not compatible with ClassDecorator
+      /* istanbul ignore next */
       throw new Error(
-        '@inject can only be used on properties or method parameters.',
+        '@inject can only be used on a property or a method parameter',
       );
     }
   };
@@ -176,11 +190,13 @@ export function describeInjectedArguments(
   target: any,
   method?: string | symbol,
 ): Injection[] {
-  if (method) {
-    return Reflector.getMetadata(PARAMETERS_KEY, target, method) || [];
-  } else {
-    return Reflector.getMetadata(PARAMETERS_KEY, target) || [];
-  }
+  method = method || '';
+  const meta = MetadataInspector.getAllParameterMetadata<Injection>(
+    PARAMETERS_KEY,
+    target,
+    method,
+  );
+  return meta || [];
 }
 
 /**
@@ -191,22 +207,11 @@ export function describeInjectedArguments(
 export function describeInjectedProperties(
   // tslint:disable-next-line:no-any
   target: any,
-): {[p: string]: Injection} {
-  const metadata: {[name: string]: Injection} = {};
-  let obj = target;
-  while (true) {
-    const m = Reflector.getOwnMetadata(PROPERTIES_KEY, obj);
-    if (m) {
-      // Adding non-existent properties
-      for (const p in m) {
-        if (!(p in metadata)) {
-          metadata[p] = m[p];
-        }
-      }
-    }
-    // Recurse into the prototype chain
-    obj = Object.getPrototypeOf(obj);
-    if (!obj) break;
-  }
+): MetadataMap<Injection> {
+  const metadata =
+    MetadataInspector.getAllPropertyMetadata<Injection>(
+      PROPERTIES_KEY,
+      target,
+    ) || {};
   return metadata;
 }

packages/context/test/unit/inject.test.ts

@@ -117,6 +117,16 @@ describe('property injection', () => {
     }).to.throw(/@inject is not supported for a static property/);
   });
 
+  it('cannot decorate a method', () => {
+    expect(() => {
+      // tslint:disable-next-line:no-unused-variable
+      class TestClass {
+        @inject('bar')
+        foo() {}
+      }
+    }).to.throw(/@inject cannot be used on a method/);
+  });
+
   it('supports inheritance without overriding property', () => {
     class TestClass {
       @inject('foo') foo: string;

packages/metadata/.gitignore

@@ -0,0 +1,3 @@
+*.tgz
+dist*
+package

packages/metadata/.npmrc

@@ -0,0 +1 @@
+package-lock=false

packages/metadata/LICENSE

@@ -0,0 +1,25 @@
+Copyright (c) IBM Corp. 2017. All Rights Reserved.
+Node module: @loopback/metadata
+This project is licensed under the MIT License, full text below.
+
+--------
+
+MIT license
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.