.NET AutoFixture with complex child properties

Question

I am exploring using AutoFixture to handle creating some of our test data for unit tests. So far, it looks like this will save us quite a bit of code/maintenance. My only issue right now is that when creating an object, the complex children objects on it will not have the IDs hooked up appropriately. I'm trying to find a way to gracefully overcome this instead of just manually hooking up the IDs after the object is created. See example below:

public class Bar
{
    public int Id {get; set;}

    public string Name {get; set;}

    public Foo Foo {get; set;}

    public int FooId {get; set;}
}

public class Foo
{
    public int Id {get; set}

    public string Description {get; set;}
}

In this example, calling var myBar = myFixture.Create<Bar>() will populate all of the properties for both Bar and it's child property Foo. My issue here is that myBar.FooId will be different than the value for myBar.Foo.Id. The same issue exists for creating child collections. How can I overcome this without manually hooking up all of my IDs?

Answer 1

Can you try this :

var obj = myFixture
    .Build<Bar>()
    .Without(b => b.Foo)
    .Without(b => b.FooId)
    .Do(b =>
        {
            b.Foo = fixture.Create<Foo>();
            b.FooId = fixture.Create<int>();
            b.Foo.Id = b.FooId;
        })
    .Create()

Or you can check this 3rd package which support the initialization of the navigation properties in EF for AutoFixture

When the interceptor creates a new navigation object, it will check for a matching int ____Id property. If present, it will set the Id property of the new object so that foo.BarId == foo.Bar.Id. This also applies when the name of the table is included in the Id property, so foo.BarId == foo.Bar.BarId.