Dependency injection creates new instance each time if used in router submodule

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Current behavior My application is divided into modules. Router navigates between modules, each child modules has some providers and some components. I expect application to reuse services injected to components within one module. However, when I navigate, service constructor is called each time component is loaded.

RootModule:

		RouterModule.forRoot([
			{ path: '', component: EmptyComponent },
			{ path: 'module', loadChildren: () => SubModule },
		]) 

SubModule:

		RouterModule.forChild([
			{ path: 'test1', component: TestComponent1 },
			{ path: 'test2', component: TestComponent2 },
		])

...
	providers:
	[
		TestService
	],

Each time I navigate between /module/test1 and /module/test2 - TestService constructor is called

Expected behavior If test1 and test2 are defined as routes in RootModule, only one instance of TestService is created. I expect SubModule to inject the same instance of TestService if I navigate between its components.

If I move TestService provider to RootModule - works as expected

Minimal reproduction of the problem with instructions https://github.com/peku33/angular2-dependency-injection-failure

What is the motivation / use case for changing the behavior? Most of components of one of modules uses a service that opens and maintains WebSocket connection. Each time a service is spawned, new connection is opened. I definitely want to reuse the component and keep single connection open than close and reopen it every time user navigates between pages.

Please tell us about your environment: Everything is up to date, browser - Chrome

• Angular version: 2.0.X Have ‘latest’ for almost everything in package.json @angular/core@2.2.0

• Browser: [all | Chrome XX | Firefox XX | IE XX | Safari XX | Mobile Chrome XX | Android X.X Web Browser | iOS XX Safari | iOS XX UIWebView | iOS XX WKWebView ]

• Language: [all | TypeScript X.X | ES6/7 | ES5]

• Node (for AoT issues): node --version =

[Keksdroid]

I’m experiencing this issue as well. Is it still a present bug or is the problem on my end?

Angular 5.1.3

[peku33]

@guojenman I know. But the problem is, that DI creates multiple objects for components inside THE SAME module