Added check for Service option

Author: Julien Heller

src/ContainerInstance.ts

@@ -6,6 +6,7 @@ import {ObjectType} from "./types/ObjectType";
 import {ServiceIdentifier} from "./types/ServiceIdentifier";
 import {ServiceMetadata} from "./types/ServiceMetadata";
 import {AsyncInitializedService} from "./types/AsyncInitializedService";
+import { MissingInitializedPromiseError } from "./error/MissingInitializedPromiseError";
 
 /**
  * TypeDI can have multiple containers.
@@ -499,10 +500,13 @@ export class ContainerInstance {
         if (type)
             this.applyPropertyHandlers(type, value);
 
-        if (value instanceof AsyncInitializedService) {
-          return new Promise((resolve) => {
-             value._initialized.then(() => resolve(value));
-          });
+        if (value instanceof AsyncInitializedService || service.asyncInitialization) {
+            return new Promise((resolve) => {
+                if (!(value._initialized instanceof Promise) && service.asyncInitialization) {
+                    throw new MissingInitializedPromiseError(service.value);
+                }
+                value._initialized.then(() => resolve(value));
+            });
         }
         return Promise.resolve(value);
     }

src/error/MissingInitializedPromiseError.ts

@@ -0,0 +1,19 @@
+/**
+ * Thrown when DI cannot inject value into property decorated by @Inject decorator.
+ */
+export class MissingInitializedPromiseError extends Error {
+    name = "MissingInitializedPromiseError";
+
+    constructor(value: any) {
+        super(
+          (value._initialized
+              ? `asyncInitialization: true was used, but ${value.name}#_initialized is not a Promise. `
+              : `asyncInitialization: true was used, but ${value.name}#_initialized is undefined. `) +
+          `You will need to either extend the abstract AsyncInitializedService class, or assign ` +
+          `${value.name}#_initialized to a Promise in your class' constructor that resolves when all required ` +
+          `initialization is complete.`
+        );
+        Object.setPrototypeOf(this, MissingInitializedPromiseError.prototype);
+    }
+
+}