UIViewController property nil in XCTestCase even thought the setup was correctly done

I have a UIViewController which has a property called persistentUserNames and i exposed this property to the XCTestClass using a category as follows. There is a method setupViews which is called on the viewDidLoad of the LoginViewController. This method initializes the array with some values.

@interface LoginViewController (Test)
    @property (strong, nonatomic) NSArray *persistentUsernames;
@end

My test setup is as follows:

- (void)setUp {
    [super setUp];
    loginViewController = [[LoginViewController alloc] initWithNibName:@"LoginViewController" bundle:nil];
    [loginViewController view];
}

Following is my test case which fails for the reason i don't know:

- (void)testSetupLoginView {
    //Given
    loginViewController.persistentUsernames = nil;
    //When
    [loginViewController setupLoginView];
    //Then
    XCTAssertNotNil(loginViewController.persistentUsernames);
}

Help would be appreciated.