Can't bind to 'navPush' since it isn't a known property of 'a'

I have an Ionic/Angular2 app and I am testing it with Jasmine. But when I run them I am getting the error

Can't bind to 'navPush' since it isn't a known property of 'a'

These are my imports

import { ComponentFixture, TestBed } from '@angular/core/testing';
import { CUSTOM_ELEMENTS_SCHEMA } from '@angular/core';
import { ReactiveFormsModule } from '@angular/forms';

import { By } from '@angular/platform-browser';
import { DebugElement } from '@angular/core';
import { async } from '@angular/core/testing';

import { SignIn } from './sign-in.component'

and this is my beforeEach

beforeEach(() => {
    TestBed.configureTestingModule({
      declarations: [ SignIn ],
      providers: [{provide: SignIn}],
      schemas: [CUSTOM_ELEMENTS_SCHEMA],
      imports: [ReactiveFormsModule]
 });

    fixture = TestBed.createComponent(SignIn);
    signInComponent = fixture.componentInstance;
});