Added a test on DebugStateService.

src/lib/debug-state.service.spec.ts

+import { marbles } from 'rxjs-marbles';
+
+import { DebugStateService } from './debug-state.service';
+
+describe('DebugStateService', () => {
+  let debugStateService: DebugStateService;
+
+  beforeEach(() => {
+    debugStateService = new DebugStateService();
+  });
+
+  it('should construct', () => {
+    expect(debugStateService).toBeDefined();
+  });
+
+  it('should ne enabled by default', () => {
+    expect(debugStateService.enabled).toBeTruthy();
+  });
+
+  it('should be disabled by toggle', () => {
+    debugStateService.toggle();
+    expect(debugStateService.enabled).toBeFalsy();
+  });
+
+  it('should be enabled again', () => {
+    debugStateService.toggle();
+    debugStateService.toggle();
+    expect(debugStateService.enabled).toBeTruthy();
+  });
+
+  it(
+    'should emit state changed',
+    marbles(m => {
+      m.scheduler.schedule(
+        () => debugStateService.toggle(),
+        m.scheduler.createTime('-|')
+      );
+
+      m.scheduler.schedule(
+        () => debugStateService.toggle(),
+        m.scheduler.createTime('---|')
+      );
+
+      m.expect(debugStateService.enabled$).toBeObservable('tf-t', {
+        f: false,
+        t: true,
+      });
+
+      expect(debugStateService.enabled).toBeTruthy();
+    })
+  );
+});

src/lib/debug-state.service.ts

 import { Injectable } from '@angular/core';
-import { BehaviorSubject } from 'rxjs';
+import { BehaviorSubject, Observable } from 'rxjs';
 import { distinctUntilChanged, map } from 'rxjs/operators';
 
-// TODO injecter
-export const environment = {
-  production: false,
-  apiURL: 'http://baliste-api.dvp',
-  api: 'http://127.0.0.101:8040',
-  geonames_api: 'http://api.geonames.org/searchJSON',
-};
-
 export const enum DebugState {
   UNAVAILABLE = -1,
   DISABLED = 0,
   ENABLED = 1,
 }
 
-@Injectable({ providedIn: 'root' })
+@Injectable()
 export class DebugStateService {
-  private readonly state$ = new BehaviorSubject<DebugState>(
-    environment.production ? DebugState.UNAVAILABLE : DebugState.ENABLED
-  );
+  private readonly state$: BehaviorSubject<DebugState>;
 
-  public readonly enabled$ = this.state$.pipe(
-    map(state => state === DebugState.ENABLED),
-    distinctUntilChanged()
-  );
+  public readonly enabled$: Observable<boolean>;
 
   public get state(): DebugState {
     return this.state$.getValue();
@@ -39,6 +26,17 @@ export class DebugStateService {
     return this.state === DebugState.ENABLED;
   }
 
+  public constructor(production: boolean = false) {
+    this.state$ = new BehaviorSubject<DebugState>(
+      production ? DebugState.UNAVAILABLE : DebugState.ENABLED
+    );
+
+    this.enabled$ = this.state$.pipe(
+      map(state => state === DebugState.ENABLED),
+      distinctUntilChanged()
+    );
+  }
+
   public toggle(): void {
     switch (this.state) {
       case DebugState.ENABLED: