Unit Test for Component

demo.component.spec.ts

import { FormBuilder } from '@angular/forms';
import { of } from 'rxjs';
import { DemoComponent } from './demo.component';

describe('DemoComponent', () => {
	let component: DemoComponent;
	let mockDeviceFulfillmentService;
	const mockFormBuilder = new FormBuilder();
	let mockActivatedRoute;
	let mockAlertToasterService;

	beforeEach(() => {
		mockActivatedRoute = {
			queryParams: of({}),
		};

		component = new DemoComponent(
			mockDeviceFulfillmentService,
			mockFormBuilder,
			mockActivatedRoute,
			mockAlertToasterService,
		);
	});

	it('should create', () => {
		expect(component).toBeTruthy();
	});
});

error-output.txt

DeviceFulfillmentListComponent
    ✕ should create (5 ms)

  ● DeviceFulfillmentListComponent › should create

    Component 'MainNavComponent' is not resolved:
     - templateUrl: ./main-nav.component.html
     - styleUrls: ["./main-nav.component.scss"]
    Did you run and wait for 'resolveComponentResources()'?

      at Function.get (../../../../node_modules/@angular/core/fesm2015/core.mjs:22659:27)
      at getComponentDef (../../../../node_modules/@angular/core/fesm2015/core.mjs:1148:12)
      at ../../../../node_modules/@angular/core/fesm2015/core.mjs:22468:34
          at Array.forEach (<anonymous>)
      at setScopeOnDeclaredComponents (../../../../node_modules/@angular/core/fesm2015/core.mjs:22463:18)
      at flushModuleScopingQueueAsMuchAsPossible (../../../../node_modules/@angular/core/fesm2015/core.mjs:22114:21)
      at TestBedImpl.checkGlobalCompilationFinished (../../../../node_modules/@angular/core/fesm2015/testing.mjs:24322:13)
      at TestBedImpl.resetTestingModule (../../../../node_modules/@angular/core/fesm2015/testing.mjs:24138:14)
      at ../../../../node_modules/@angular/core/fesm2015/testing.mjs:24495:21
      at _ZoneDelegate.Object.<anonymous>._ZoneDelegate.invoke (../../../../node_modules/zone.js/bundles/zone-testing-bundle.umd.js:412:30)
      at ProxyZoneSpec.Object.<anonymous>.ProxyZoneSpec.onInvoke (../../../../node_modules/zone.js/bundles/zone-testing-bundle.umd.js:3833:43)
      at _ZoneDelegate.Object.<anonymous>._ZoneDelegate.invoke (../../../../node_modules/zone.js/bundles/zone-testing-bundle.umd.js:411:56)
      at Zone.Object.<anonymous>.Zone.run (../../../../node_modules/zone.js/bundles/zone-testing-bundle.umd.js:169:47)
      at Object.wrappedFunc (../../../../node_modules/zone.js/bundles/zone-testing-bundle.umd.js:4333:34)

Test Suites: 1 failed, 1 total
Tests:       1 failed, 1 total
Snapshots:   0 total
Time:        21.427 s
Ran all test suites related to changed files.