feat(container): add self registration of container in constructor, test, and document it

Author: Tolowe

examples/javascript/resolving-container.js

@@ -0,0 +1,12 @@
+import { Container, TContainer, Injectable } from 'container-ioc';
+
+const container = new Container();
+
+@Injectable([TContainer])
+class Builder {
+    constructor(container) {}
+}
+
+container.register({ token: Builder, useClass: Builder });
+
+const builder = container.resolve(Builder);

examples/typescript/resolving-container.ts

@@ -0,0 +1,12 @@
+import { IContainer, Container, TContainer, Injectable, Inject } from 'container-ioc';
+
+const container = new Container();
+
+@Injectable()
+class Builder {
+    constructor(@Inject(TContainer) private container: IContainer) {}
+}
+
+container.register({ token: Builder, useClass: Builder });
+
+const builder = container.resolve(Builder);

src/lib/container.interface.ts

@@ -6,6 +6,8 @@ export interface IContainerOptions {
 }
 
 export interface IContainer {
+    [key: string]: any;
+    
     register(provider: RegistrationProvider|RegistrationProvider[]): void;
 
     resolve(token: ProviderToken): IInjectionInstance;
@@ -18,4 +20,6 @@ export interface IContainer {
     createChild(): IContainer;
 
     setParent(parent: IContainer): void;
-}
+}
+
+export const TContainer = Symbol('IContainer');

src/lib/container.ts

@@ -1,6 +1,6 @@
 import { IConstructor, IInjectionInstance, IInjectionMd, IProvider, LifeTime, ProviderToken, RegistrationProvider } from './interfaces';
 import { FactoryFunction, IFactory, IRegistryData, RegistryData } from './registry-data';
-import { IContainer, IContainerOptions } from './container.interface';
+import { IContainer, IContainerOptions, TContainer } from './container.interface';
 import { ClassNotInjectableError, InvalidProviderProvidedError, NoProviderError } from './exceptions';
 import { INJECTABLE_MD_KEY, INJECTIONS_MD_KEY } from './metadata/keys';
 import { IMetadataAnnotator } from './metadata/metadata-annotator.interface';
@@ -21,6 +21,7 @@ export class Container implements IContainer {
             this.parent = <IContainer> options.parent;
             this.defaultLifeTime = options.defaultLifeTime || this.defaultLifeTime;
         }
+        this.register({ token: TContainer, useValue: this });
     }
 
     public register(provider: RegistrationProvider|RegistrationProvider[]): void {

src/lib/index.ts

@@ -1,5 +1,5 @@
 export { Container } from './container';
-export { IContainer } from './container.interface';
+export { IContainer, TContainer } from './container.interface';
 export { Inject, Injectable } from './decorators';
 export { InjectionToken } from './injection-token';
 export { IMetadataAnnotator } from './metadata/metadata-annotator.interface';

src/tests/container.spec.ts

@@ -1,4 +1,4 @@
-import { IContainer } from '../lib/container.interface';
+import { IContainer, TContainer } from '../lib/container.interface';
 import { Container } from '../lib/index';
 
 import 'mocha';
@@ -356,6 +356,21 @@ describe('Container', () => {
 
                 expect(throwableFunc).to.throw('No provider for IB. Trace: IA --> IB');
             });
+
+            it('should resolve container instance when injected into class Literal', () => {
+                // arrange
+                @Injectable()
+                class TestClass {
+                    constructor(@Inject(TContainer) public a: IContainer) {}
+                }
+                container.register({ token: TestClass, useClass: TestClass });
+                // act
+                const actual = container.resolve(TestClass);
+                // assert
+                expect(actual).to.be.ok;
+                expect(actual.a).to.be.ok;
+                expect(actual.a).to.equal(container);
+            });
         });
 
         describe('Hierarchial', () => {
@@ -449,6 +464,14 @@ describe('Container', () => {
 
             expect(instance1).not.to.be.equal(instance2);
         });
+
+        it('should register itself for injection', () => {
+            // arrange, act
+            const actual = container.resolve(TContainer);
+            // assert
+            expect(actual).to.be.ok;
+            expect(actual).to.equal(container);
+        });
     });
 
     describe('createChild()', () => {
@@ -471,5 +494,5 @@ describe('Container', () => {
 
             expect(value).to.be.equal('string');
         });
-    });
+    });    
 });