Question

Just getting started with MSpec and I can’t seem to quite get my first spec to pass. Whilst checking the source code is ideal, I don’t really want to spend ages doing that right now.

The problem is that Because causes a null reference exception – the repository is null.

A breakpoint on Establish gets hit (but not when I put it in the base class) but I guess the code inside is not being run causing my error.

Any help would be great – explanations and links also appreciated very much.

[Subject("Sandwich Repository CRUD")]
public class sandwich_repository_can_save_sandwiches : SandwichRepositoryContext
{
    Establish context = () =>
    {
        sandwich = new Sandwich(ValidSandwichName);
        repository = new SandwichRepository();
    };

    Because of = () => { repository.Save(sandwich); };

    It should_contain_the_created_sandwich = repository.GetSandwichByName(ValidSandwichName).ShouldNotBeNull;
}

public abstract class SandwichRepositoryContext
{
    protected static Sandwich sandwich;
    protected const string ValidSandwichName = "Olive Le Fabulos";
    protected static SandwichRepository repository;
}

Answer 1

Your code looks good, although the It seems to miss the lambda operator and parenthesis on ShouldNotBeNull. Does this work for you?

[Subject("Sandwich Repository CRUD")]
public class when_a_sandwich_is_created : SandwichRepositoryContext
{
    Establish context = () =>
    {
        sandwich = new Sandwich(ValidSandwichName);
        repository = new SandwichRepository();
    };

    Because of = () => { repository.Save(sandwich); };

    It should_find_the_created_sandwich =
        () => repository.GetSandwichByName(ValidSandwichName).ShouldNotBeNull();
}

public abstract class SandwichRepositoryContext
{
    protected static Sandwich sandwich;
    protected const string ValidSandwichName = "Olive Le Fabulos";
    protected static SandwichRepository repository;
}

Here’s the infrastructure code I used to verify that the context above passes:

public class SandwichRepository
{
    Sandwich _saved;

    public void Save(Sandwich sandwich)
    {
        _saved = sandwich;
    }

    public Sandwich GetSandwichByName(string validSandwichName)
    {
        if (_saved.ValidSandwichName == validSandwichName)
            return _saved;

        return null;
    }
}

public class Sandwich
{
    public string ValidSandwichName
    {
        get;
        set;
    }

    public Sandwich(string validSandwichName)
    {
        ValidSandwichName = validSandwichName;
    }
}