I am trying to mock my EF6 DbContext
and it all works for Add
, Update
, Find
methods. But it's not working for Remove
method for unknown reason.
In theory, after removing, the Students
collection should have only 1 return left. But it keeps returning the Count - 2.
I put 3 Moq.Verify
checks to ensure that all methods are called and they are executed indeed. But it's not actually removing the item from the Students Collection.
If I commented Assert.Equal
line which check the counts, the whole test passed.
Delete XUnit Method
[Fact]
public void Delete()
{
Mock<DbContexts.MVCWebAppDbContext> dbContext = new Mock<DbContexts.MVCWebAppDbContext>();
IStudentsService studentService = new StudentsService(dbContext.Object);
var students = new List<Student>()
{
new Student() { StudentID = 1, RefNo = "12456343", FirstName = "John", LastName = "Smith", DateOfBirth = DateTime.Now.AddYears(-10), DateCreated = DateTime.Now },
new Student() { StudentID = 2, RefNo = "87984564", FirstName = "Pete", LastName = "Luck", DateOfBirth = DateTime.Now.AddYears(-20), DateCreated = DateTime.Now.AddDays(1) }
};
var mockSet = new Mock<DbSet<Student>>();
mockSet.As<IQueryable<Student>>().Setup(m => m.Provider).Returns(students.AsQueryable().Provider);
mockSet.As<IQueryable<Student>>().Setup(m => m.Expression).Returns(students.AsQueryable().Expression);
mockSet.As<IQueryable<Student>>().Setup(m => m.ElementType).Returns(students.AsQueryable().ElementType);
mockSet.As<IQueryable<Student>>().Setup(m => m.GetEnumerator()).Returns(students.AsQueryable().GetEnumerator());
mockSet.Setup(m => m.Remove(It.IsAny<Student>())).Callback<Student>((entity) => students.Remove(entity));
dbContext.Setup(c => c.Students).Returns(mockSet.Object);
int idToDelete = 1;
dbContext.Setup(s => s.Students.Find(idToDelete)).Returns(students.Single(s => s.StudentID == idToDelete));
// call delete method now
studentService.Delete(idToDelete);
// 1 object deleted, it should return 1
Assert.Equal(1, students.Count()); // <----- Error here
dbContext.Verify(s => s.Students.Find(idToDelete), Times.Once);
dbContext.Verify(s => s.Students.Remove(It.IsAny<Student>()), Times.Once);
dbContext.Verify(s => s.SaveChanges(), Times.Once);
}
StudentService.cs Delete method
MVCWebAppDbContext _context;
public StudentsService(MVCWebAppDbContext context)
{
_context = context;
}
public int Delete(int id)
{
var objToDelete = _context.Students.Find(id);
if (objToDelete != null)
{
_context.Students.Remove(objToDelete);
return _context.SaveChanges();
}
return -1;
}
Could you guys please help me with this Remove method mocking?
replace
mockSet
.Setup(m => m.Remove(It.IsAny<Student>()))
.Callback<Student>((entity) => students.Remove(entity));
with
dbContext
.Setup(m => m.Students.Remove(It.IsAny<Student>()))
.Callback<Student>((entity) => students.Remove(entity));
Most of the setup was done using the DbContext.Students
which overrides the setup on DbSet.Remove
In fact you can actually remove all the DbSet
mocking and test would still pass
[Fact]
public void Delete() {
var dbContext = new Mock<DbContexts.MVCWebAppDbContext>();
IStudentsService studentService = new StudentsService(dbContext.Object);
var students = new List<Student>()
{
new Student() { StudentID = 1, RefNo = "12456343", FirstName = "John", LastName = "Smith", DateOfBirth = DateTime.Now.AddYears(-10), DateCreated = DateTime.Now },
new Student() { StudentID = 2, RefNo = "87984564", FirstName = "Pete", LastName = "Luck", DateOfBirth = DateTime.Now.AddYears(-20), DateCreated = DateTime.Now.AddDays(1) }
};
dbContext
.Setup(m => m.Students.Remove(It.IsAny<Student>()))
.Callback<Student>((entity) => students.Remove(entity));
int idToDelete = 1;
dbContext
.Setup(s => s.Students.Find(idToDelete))
.Returns(students.Single(s => s.StudentID == idToDelete));
// call delete method now
studentService.Delete(idToDelete);
// 1 object deleted, it should return 1
Assert.AreEqual(1, students.Count());
dbContext.Verify(s => s.Students.Find(idToDelete), Times.Once);
dbContext.Verify(s => s.Students.Remove(It.IsAny<Student>()), Times.Once);
dbContext.Verify(s => s.SaveChanges(), Times.Once);
}