docs: add documentation for inheritance

Author: NoNameProvided

docs/README.md

@@ -86,7 +86,6 @@ Container.set([
 - [Using factory function to create service](#using-factory-function-to-create-service)
 - [Using factory class to create service](#using-factory-class-to-create-service)
 - [Problem with circular references](#problem-with-circular-references)
-- [Inherited injections](#inherited-injections)
 - [Custom decorators](#custom-decorators)
 - [Using service groups](#using-service-groups)
 - [Using multiple containers and scoped containers](#using-multiple-containers-and-scoped-containers)
@@ -184,26 +183,6 @@ export class Engine {
 
 And that's all. Same for constructor injections.
 
-### Inherited injections
-
-Inherited injections are supported as well. In order to use them you must mark inherited class as a @Service.
-For example:
-
-```typescript
-// Car.ts
-@Service()
-export abstract class Car {
-  @Inject()
-  engine: Engine;
-}
-
-// Engine.ts
-@Service()
-export class Bus extends Car {
-  // you can call this.engine in this class
-}
-```
-
 ### Custom decorators
 
 You can create your own decorators which will inject your given values for your service dependencies.

docs/SUMMARY.md

@@ -8,6 +8,7 @@
   - [@Service decorator](typescript/04-service-decorator.md)
   - [@Inject decorator](typescript/05-inject-decorator.md)
   - [Service Tokens](typescript/06-service-tokens.md)
+  - [Inheritance](typescript/07-inheritance.md)
   - [Usage with TypeORM](typescript/07-usage-with-typeorm.md)
 - Advanced Usage
   - [Creating custom decorators](typescript/08-custom-decorators.md)

docs/typescript/07-inheritance.md

@@ -0,0 +1,36 @@
+# Inheritance
+
+Inheritance is supported **for properties** when both the base and the extended class is marked with the `@Service()` decorator.
+Classes which extends a class with decorated properties will receive the initialized class instances on those properties upon creation.
+
+```ts
+import 'reflect-metadata';
+import { Container, Token, Inject, Service } from 'typedi';
+
+@Service()
+class InjectedClass {
+  name: string = 'InjectedClass';
+}
+
+@Service()
+class BaseClass {
+  name: string = 'BaseClass';
+
+  @Inject()
+  injectedClass: InjectedClass;
+}
+
+@Service()
+class ExtendedClass extends BaseClass {
+  name: string = 'ExtendedClass';
+}
+
+const instance = Container.get(ExtendedClass);
+// instance has the `name` property with "ExtendedClass" value (overwritten the base class)
+// and the `injectedClass` property with the instance of the `InjectedClass` class
+
+console.log(instance.injectedClass.name);
+// logs "InjectedClass"
+console.log(instance.name);
+// logs "ExtendedClass"
+```