gistfile1.txt

- (void)testRelationshipUserTodos
{
    
//  Create User and Todos
    
    User *user = [NSEntityDescription insertNewObjectForEntityForName:@"User" inManagedObjectContext:self.moc];
    [user setEmail:@"[email protected]"];
    
    Todo *todo_1 = [NSEntityDescription insertNewObjectForEntityForName:@"Todo" inManagedObjectContext:self.moc];
    [todo_1 setAction:@"first"];
    [todo_1 setUser:user];
    
    Todo *todo_2 = [NSEntityDescription insertNewObjectForEntityForName:@"Todo" inManagedObjectContext:self.moc];
    [todo_2 setAction:@"second"];
    [todo_2 setUser:user];
    
    NSError *error = nil;
    BOOL result = [self.moc save:&error];
    
    XCTAssertNil(error, @"save should not raise errors");
    XCTAssertTrue(result, @"save should be true");

//  Fetch user and todos
    
    NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init];
    NSEntityDescription *entity = [NSEntityDescription entityForName:@"User" inManagedObjectContext:self.moc];
    [fetchRequest setEntity:entity];
    NSArray *fetchedObjects = [self.moc executeFetchRequest:fetchRequest error:&error];

//  Check that user.todos is array of 2 objects
    
    NSObject *fetchedUser = [fetchedObjects firstObject];
    NSArray *todos = [fetchedUser valueForKey:@"todos"];
    XCTAssertTrue([todos count] == 2, @"user should have 2 todos");
}