Implements #505 (#512)

* Implemments #505

* Added docs for #505

Author: remojansen

package.json

@@ -1,6 +1,6 @@
 {
   "name": "inversify",
-  "version": "3.2.0",
+  "version": "3.3.0",
   "description": "A powerful and lightweight inversion of control container for JavaScript and Node.js apps powered by TypeScript.",
   "main": "lib/inversify.js",
   "jsnext:main": "es/inversify.js",

src/container/container.ts

@@ -254,6 +254,13 @@ class Container implements interfaces.Container {
         return this.getAllTagged<T>(serviceIdentifier, METADATA_KEY.NAMED_TAG, named);
     }
 
+    public resolve<T>(constructorFunction: interfaces.Newable<T>) {
+        const tempContainer = new Container();
+        tempContainer.bind<T>(constructorFunction).toSelf();
+        tempContainer.parent = this;
+        return tempContainer.get<T>(constructorFunction);
+    }
+
     // Prepares arguments required for resolution and
     // delegates resolution to _middleware if available
     // otherwise it delegates resoltion to _planAndResolve

src/interfaces/interfaces.ts

@@ -174,6 +174,7 @@ namespace interfaces {
         getNamed<T>(serviceIdentifier: ServiceIdentifier<T>, named: string|number|symbol): T;
         getTagged<T>(serviceIdentifier: ServiceIdentifier<T>, key: string|number|symbol, value: any): T;
         getAll<T>(serviceIdentifier: ServiceIdentifier<T>): T[];
+        resolve<T>(constructorFunction: interfaces.Newable<T>): T;
         load(...modules: ContainerModule[]): void;
         unload(...modules: ContainerModule[]): void;
         applyCustomMetadataReader(metadataReader: MetadataReader): void;

test/features/resolve_unbinded.test.ts

@@ -0,0 +1,35 @@
+import { expect } from "chai";
+import { Container, injectable } from "../../src/inversify";
+
+describe("Container.prototype.resolve", () => {
+
+    it("Should be able to resolve a class that has not binded", () => {
+
+        @injectable()
+        class Katana {
+            public hit() {
+                return "cut!";
+            }
+        }
+
+        @injectable()
+        class Ninja implements Ninja {
+            public katana: Katana;
+            public constructor(katana: Katana) {
+                this.katana = katana;
+            }
+            public fight() { return this.katana.hit(); }
+        }
+
+        const container = new Container();
+        container.bind(Katana).toSelf();
+
+        const tryGet = () => container.get(Ninja);
+        expect(tryGet).to.throw("No matching bindings found for serviceIdentifier: Ninja");
+
+        const ninja = container.resolve(Ninja);
+        expect(ninja.fight()).to.eql("cut!");
+
+    });
+
+});

wiki/container_api.md

@@ -278,4 +278,36 @@ container.rebind<number>(TYPES.someType).toConstantValue(3);
 let values2 = container.getAll(TYPES.someType);
 expect(values2[0]).to.eq(3);
 expect(values2[1]).to.eq(undefined);
-```
+```
+
+## container.resolve<T>(constructor: Newable<T>)
+Resolve is like `container.get<T>(serviceIdentifier: ServiceIdentifier<T>)` but it allows users to create an instance wven if no bindings have been declared:
+
+```ts
+@injectable()
+class Katana {
+    public hit() {
+        return "cut!";
+    }
+}
+
+@injectable()
+class Ninja implements Ninja {
+    public katana: Katana;
+    public constructor(katana: Katana) {
+        this.katana = katana;
+    }
+    public fight() { return this.katana.hit(); }
+}
+
+const container = new Container();
+container.bind(Katana).toSelf();
+
+const tryGet = () => container.get(Ninja);
+expect(tryGet).to.throw("No matching bindings found for serviceIdentifier: Ninja");
+
+const ninja = container.resolve(Ninja);
+expect(ninja.fight()).to.eql("cut!");
+```
+
+Please note that it only allows to skip declaring a binding for the root element in the dependency graph (composition root). All the sub-dependencies (e.g. `Katana` in the preceding example) will require a binding to be declared.