#102 simplify syntax

.gitignore

@@ -4,4 +4,5 @@ src/**/*.js*
 *.d.ts
 dist
 usage.js
-CURRENT-CHANGELOG.txt
+CURRENT-CHANGELOG.txt
+yarn.lock

README.md

@@ -209,6 +209,21 @@ container.register([
     { token: App, useClass: App }
 ]);
 ```
+In such case it is redundant to use `Inject()` decorator, dependency will be injected automatically.
+```typescript
+@Injectable()
+class AppService {
+    constructor(private http: HttpService) {} // instead of @Inject(HttpService) private http: HttpService
+}
+
+@Injectable()
+class HttpService {
+
+}
+
+container.register([HttpService, AppService])
+```
+
 
 ## Contribution
 Become a contributor to this project. Feel free to submit an [issue](https://github.com/thohoh/container-ioc/issues) or a pull request.

package.json

@@ -58,6 +58,7 @@
     "gulp-tslint": "8.1.2",
     "gulp-typescript": "3.2.2",
     "mocha": "3.5.3",
+    "reflect-metadata": "^0.1.12",
     "tslint": "5.7.0",
     "tslint-microsoft-contrib": "5.0.1",
     "typescript": "2.5.3"

src/lib/decorators.ts

@@ -2,6 +2,7 @@ import { IInjectionMd, ProviderToken } from './interfaces';
 import { INJECTABLE_MD_KEY, INJECTIONS_MD_KEY } from './metadata/keys';
 import { IMetadataAnnotator } from './metadata/metadata-annotator.interface';
 import { AnnotatorProvider } from './metadata/index';
+import 'reflect-metadata';
 
 const MetadataAnnotator: IMetadataAnnotator = AnnotatorProvider.get();
 
@@ -14,6 +15,17 @@ export function Injectable(injections?: ProviderToken[]) {
             injections.forEach(token => injectionsMd.push(token));
             MetadataAnnotator.defineMetadata(INJECTIONS_MD_KEY, injectionsMd, target);
         }
+
+        const parameters = Reflect.getMetadata('design:paramtypes', target);
+        if (parameters && Array.isArray(parameters)) {
+            const injectionsMd: IInjectionMd[] = MetadataAnnotator.getMetadata(INJECTIONS_MD_KEY, target) || [];
+            parameters.forEach((param, index) => {
+                if (param['DI:injectable'] && !injectionsMd[index]) {
+                    injectionsMd[index] = param;
+                }
+            });
+            MetadataAnnotator.defineMetadata(INJECTIONS_MD_KEY, injectionsMd, target);
+        }
     };
 }
 

src/tests/decorators.spec.ts

@@ -4,6 +4,7 @@ import { Container } from '../lib/index';
 import 'mocha';
 import { expect } from 'chai';
 import { Inject, Injectable } from '../lib/decorators';
+import { RegistrationProvider } from '../lib/interfaces';
 
 /* tslint:disable: no-unused-expression max-classes-per-file*/
 
@@ -34,6 +35,23 @@ describe('Decorators', () => {
             expect(instanceB.a).to.be.instanceOf(A);
         });
 
+        it('should inject dependency in to the constructor of a resolved class wihout @Inject keyword', () => {
+
+            @Injectable()
+            class A { }
+
+            @Injectable()
+            class B {
+                constructor(private a: A) { }
+            }
+
+            container.register([A, B]);
+
+            const instanceB = container.resolve(B);
+
+            expect(instanceB.a).to.be.instanceOf(A);
+        });
+
         it('should throw an error when wrong token was provided not registered token', () => {
             @Injectable()
             class A {}