fix: detection of empty modules in mock process

closes #142

lib/mock-module/mock-module.ts

@@ -7,6 +7,7 @@ import {
   flatten,
   getMockedNgDefOf,
   isNgDef,
+  isNgInjectionToken,
   isNgModuleDefWithProviders,
   Mock,
   MockOf,
@@ -160,7 +161,7 @@ const NEVER_MOCK: Array<Type<any>> = [CommonModule, ApplicationModule];
 
 // tslint:disable-next-line:cyclomatic-complexity
 function MockNgModuleDef(ngModuleDef: NgModule, ngModule?: Type<any>): [boolean, NgModule] {
-  let changed = false;
+  let changed = !ngMocksUniverse.flags.has('skipMock');
   const mockedModuleDef: NgModule = {};
   const {
     bootstrap = [],
@@ -204,7 +205,9 @@ function MockNgModuleDef(ngModuleDef: NgModule, ngModule?: Type<any>): [boolean,
       mockedDef = MockProvider(def);
     }
 
-    resolutions.set(provider, mockedDef);
+    if (!isNgInjectionToken(provider) || def !== mockedDef) {
+      resolutions.set(provider, mockedDef);
+    }
     changed = changed || mockedDef !== def;
     return multi && typeof mockedDef === 'object' ? { ...mockedDef, multi } : mockedDef;
   };

tests/issue-142/test.spec.ts

@@ -0,0 +1,47 @@
+import { Component, Inject, InjectionToken, NgModule } from '@angular/core';
+import { TestBed } from '@angular/core/testing';
+import { MockModule } from 'ng-mocks';
+
+export const TARGET_TOKEN = new InjectionToken('TARGET_TOKEN');
+
+@NgModule()
+export class TargetModule {
+  public static forRoot() {
+    return {
+      ngModule: TargetModule,
+      providers: [
+        {
+          multi: true,
+          provide: TARGET_TOKEN,
+          useValue: true,
+        },
+      ],
+    };
+  }
+
+  public readonly targetToken: boolean = false;
+
+  constructor(@Inject(TARGET_TOKEN) targetToken: boolean) {
+    this.targetToken = targetToken;
+  }
+}
+
+@Component({
+  selector: 'target',
+  template: 'target',
+})
+export class TargetComponent {}
+
+describe('issue-142', () => {
+  beforeEach(() =>
+    TestBed.configureTestingModule({
+      declarations: [TargetComponent],
+      imports: [MockModule(TargetModule.forRoot())],
+    }).compileComponents()
+  );
+
+  it('test', () => {
+    const fixture = TestBed.createComponent(TargetComponent);
+    expect(fixture).toBeDefined();
+  });
+});