From edd7314624a1b65516947276ab32e5a5bdc99ba7 Mon Sep 17 00:00:00 2001
From: alecmerdler <merdlera@oregonstate.edu>
Date: Sat, 21 Jan 2017 02:56:29 -0800
Subject: [PATCH] @Inject decorator for easily annotating dependency-injected
 class constructors

---
 .../decorators/inject/inject.decorator.spec.ts  | 17 +++++++++++++++++
 static/js/decorators/inject/inject.decorator.ts | 11 +++++++++++
 .../services/view-array/view-array.factory.ts   |  4 ++--
 .../services/view-array/view-array.impl.spec.ts |  4 ++--
 tsconfig.json                                   |  1 +
 5 files changed, 33 insertions(+), 4 deletions(-)
 create mode 100644 static/js/decorators/inject/inject.decorator.spec.ts
 create mode 100644 static/js/decorators/inject/inject.decorator.ts

diff --git a/static/js/decorators/inject/inject.decorator.spec.ts b/static/js/decorators/inject/inject.decorator.spec.ts
new file mode 100644
index 000000000..2f0a9a17b
--- /dev/null
+++ b/static/js/decorators/inject/inject.decorator.spec.ts
@@ -0,0 +1,17 @@
+import { Inject } from './inject.decorator';
+
+
+describe("Decorator: Inject", () => {
+
+  describe("parameter injection", () => {
+
+    it("adds given string to the 'inject' property of the annotated class", () => {
+      expect(ValidService.$inject).toContain('$scope');
+    });
+  });
+});
+
+
+class ValidService {
+  constructor(@Inject('$scope') private $scope: any) {}
+}
\ No newline at end of file
diff --git a/static/js/decorators/inject/inject.decorator.ts b/static/js/decorators/inject/inject.decorator.ts
new file mode 100644
index 000000000..2c647a4c7
--- /dev/null
+++ b/static/js/decorators/inject/inject.decorator.ts
@@ -0,0 +1,11 @@
+/**
+ * Adds the given value to the inject property of the annotated class.
+ * Used to annotate the constructor parameters of an AngularJS service/component class.
+ * @param value The string name of the dependency.
+ */
+export function Inject(value: string) {
+  return (target: any, propertyKey: string | symbol, parameterIndex: number): void => {
+    target.$inject = target.$inject || [];
+    target.$inject[parameterIndex] = value;
+  }
+}
diff --git a/static/js/services/view-array/view-array.factory.ts b/static/js/services/view-array/view-array.factory.ts
index 0a4a4de2d..99601e759 100644
--- a/static/js/services/view-array/view-array.factory.ts
+++ b/static/js/services/view-array/view-array.factory.ts
@@ -1,5 +1,6 @@
 import { ViewArray } from './view-array';
 import { ViewArrayImpl } from './view-array.impl';
+import { Inject } from '../../decorators/inject/inject.decorator';
 
 
 /**
@@ -13,8 +14,7 @@ export class ViewArrayFactory {
    * @param $interval Angular $interval service.
    * @return viewArrayFactory A factory for creating ViewArray objects.
    */
-  static $inject = ['$interval'];
-  constructor(private $interval: ng.IIntervalService) {
+  constructor(@Inject('$interval') private $interval: ng.IIntervalService) {
 
   }
 
diff --git a/static/js/services/view-array/view-array.impl.spec.ts b/static/js/services/view-array/view-array.impl.spec.ts
index 82128e5bf..ae9ee113b 100644
--- a/static/js/services/view-array/view-array.impl.spec.ts
+++ b/static/js/services/view-array/view-array.impl.spec.ts
@@ -6,13 +6,13 @@ describe("ViewArrayImplImpl", () => {
   var $intervalMock: any;
   var additionalCount: number;
 
-  beforeEach(inject(($injector: ng.auto.IInjectorService) => {
+  beforeEach(() => {
     $intervalMock = jasmine.createSpy('$intervalSpy');
     $intervalMock.and.returnValue({});
     $intervalMock.cancel = jasmine.createSpy('cancelSpy');
     additionalCount = 20;
     viewArrayImpl = new ViewArrayImpl($intervalMock, additionalCount);
-  }));
+  });
 
 
   describe("constructor", () => {
diff --git a/tsconfig.json b/tsconfig.json
index 2e7ab719c..9ec73f044 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -5,6 +5,7 @@
     "module": "commonjs",
     "outDir": "./build/",
     "target": "es5",
+    "experimentalDecorators": true,
     "sourceMap": true,
     "paths": {
       "sass/*": ["./static/css/directives/components/pages/*"]