Angular 4 Circular dependency detected

As the warning says, work-session-list.routing.ts depends on index.ts:

import { WorkSessionListComponent } from './index';

And index.ts depends on work-session-list.routing.ts:

export * from './work-session-list.routing';

The first dependency is not necessary, since you could import WorkSessionListComponent directly from its source file:

import { WorkSessionListComponent } from './work-session-list.component';

This change should fix the problem.