public async Task GetAllShouldReturnCorrectNumberUsingDbContext()
{
var options = new DbContextOptionsBuilder <ApplicationDbContext>()
.UseInMemoryDatabase(databaseName: Guid.NewGuid().ToString()).Options;
var dbContext = new ApplicationDbContext(options);
dbContext.Companies.Add(new Company());
dbContext.Companies.Add(new Company());
dbContext.Companies.Add(new Company());
await dbContext.SaveChangesAsync();
var repository = new EfDeletableEntityRepository <Company>(dbContext);
var service = new CompaniesService(repository);
Assert.Equal(3, await service.GetCountAsync());
}