Merge pull request #186 from DrSammyD/master

Fix autoinject to allow abstract classes

Author: EisenbergEffect

src/injection.ts

@@ -1,18 +1,25 @@
 import { metadata } from 'aurelia-metadata';
 import { _emptyParameters } from './container';
-import { DependencyCtor, Args, Impl } from './types';
+import { Args, Impl, DependencyCtor } from './types';
+
+// tslint:disable-next-line:ban-types
+export type Injectable = Function & { inject?: any[] | (() => any[]) };
+
+function isInjectable(potentialTarget: any): potentialTarget is Injectable {
+  return !!potentialTarget;
+}
 
 /**
  * Decorator: Directs the TypeScript transpiler to write-out type metadata for
  * the decorated class.
  */
-export function autoinject(
-  potentialTarget?: DependencyCtor<any, any, any>
-): any {
-  const deco = (target: DependencyCtor<any, any, any> & { inject?: any }) => {
+export function autoinject<TPotential>(
+  potentialTarget?: TPotential
+): TPotential extends Injectable ? void : (target: Injectable) => void {
+  const deco = (target: Injectable): void => {
     if (!target.hasOwnProperty('inject')) {
       target.inject = (
-        (metadata.getOwn(metadata.paramTypes, target) as Array<any>) ||
+        (metadata.getOwn(metadata.paramTypes, target) as any[]) ||
         _emptyParameters
       ).slice();
       if (target.inject && target.inject.length > 0) {
@@ -25,10 +32,11 @@ export function autoinject(
       }
     }
   };
-
-  return potentialTarget ? deco(potentialTarget) : deco;
+  if (isInjectable(potentialTarget)) {
+    return deco(potentialTarget) as TPotential extends Injectable ? void : (target: Injectable) => void;
+  }
+  return deco as TPotential extends Injectable ? void : (target: Injectable) => void;
 }
-
 /**
  * Decorator: Specifies the dependencies that should be injected by the DI Container into the decorated class/function.
  */

test/injection.spec.ts

@@ -172,7 +172,7 @@ describe('injection', () => {
 
     describe('inheritance', () => {
       @autoinject()
-      class ParentApp {
+      abstract class ParentApp {
         constructor(public logger: Logger) {
           this.logger = logger;
         }

test/resolver.spec.ts

@@ -78,7 +78,7 @@ describe('resolver', () => {
 
         class Logger extends LoggerBase { }
 
-        @autoinject()
+        @autoinject
         class App {
           constructor(@all(LoggerBase) public loggers) {
             this.loggers = loggers;
@@ -150,7 +150,7 @@ describe('resolver', () => {
         class VerboseLogger { }
         class Logger { }
 
-        @autoinject()
+        @autoinject
         class App {
           constructor(@optional() public logger: Logger) {
           }
@@ -241,7 +241,7 @@ describe('resolver', () => {
       it('checks the parent container hierarchy when checkParent is true or default using decorator', () => {
         class Logger { }
 
-        @autoinject()
+        @autoinject
         class App {
           constructor(@optional() public logger: Logger) {
           }
@@ -325,7 +325,7 @@ describe('resolver', () => {
       it('returns null when no parent container exists using decorator', () => {
         class Logger { }
 
-        @autoinject()
+        @autoinject
         class App {
           constructor(@parent public logger: Logger) {
           }
@@ -442,7 +442,7 @@ describe('resolver', () => {
       });
 
       it('decorate to inject a new instance of a dependency', () => {
-        @autoinject()
+        @autoinject
         class App1 {
           constructor(@newInstance() public logger: Logger) {
           }
@@ -488,7 +488,7 @@ describe('resolver', () => {
       });
 
       it('decorate to inject a new instance of a dependency, with instance dynamic dependency', () => {
-        @autoinject()
+        @autoinject
         class App1 {
           constructor(@newInstance(Logger, Dependency) public logger: Logger) {
           }
@@ -550,7 +550,7 @@ describe('resolver', () => {
     class SubService1 { }
     class SubService2 { }
 
-    @autoinject()
+    @autoinject
     abstract class ParentApp {
       constructor(@lazy(Logger) public logger: () => Logger) { }
     }
@@ -562,7 +562,7 @@ describe('resolver', () => {
       }
     }
 
-    @autoinject()
+    @autoinject
     class SubChildApp1 extends ChildApp {
       constructor(@lazy(SubService1) public subService1: () => SubService1,
                   service: Service, @lazy(Logger) ...rest: [() => Logger]) {
@@ -582,7 +582,7 @@ describe('resolver', () => {
     class SubChildApp3 extends ChildApp {
     }
 
-    @autoinject()
+    @autoinject
     class SubChildApp4 extends ChildApp {
       constructor(@lazy(Logger) logger: () => Logger,
                   @lazy(SubService1) public subService1: () => SubService1, service: Service) {
@@ -644,7 +644,7 @@ describe('resolver', () => {
         }
       }
 
-      @autoinject()
+      @autoinject
       class App {
         public service: Service & { data: string };
         constructor(