How to unit test a prompt validator in Bot Framework V4

Question

In my dialog I use a validator to check the users input. I have a line that looks like this:

AddDialog(new TextPrompt(nameof(AskForCustomerId), validators.TestValidator));

I also have a class which contains my validations for this dialog. The class looks like this:

public class MyValidator : IMyValidator
{
    public async Task<bool> TestValidator(PromptValidatorContext<string> promptContext, CancellationToken cancellationToken)
    {
        // Do some validations...
        
        return true;
    }
}

I thought that it's a good idea to have my validation code separated in another class.

But now I'd like to write unit tests for this particular class. But how can I do this?

I tried the following, but I can't create an instance of PromptValidatorContext , because the constructor is internal...

[Fact]
public void Test()
{
    // Arrange
    var sut = new MyValidator(sessionManagerMock.Object);
    var prompt = new PromptValidatorContext(); // ctor is internal.. cant create instance.

    // Act
    sut.TestValidator( ) // How to pass params?

    // Assert
}

Anyone any idea how to unit test this?

---

Update

So I have a Dialog in which I inject my "Validator" class. My Dialog class looks like this:

public class MyDialog : BaseDialog
{

    public MyDialog(ICustomerValidator validator) : ComponentDialog
    {
        AddDialog(new WaterfallDialog(nameof(WaterfallDialog),
            new WaterfallStep[]
            {
                // ... my steps
            }));

        AddDialog(new TextPrompt(nameof(Step1Example)));
        AddDialog(new TextPrompt(nameof(Step2Example), validator.CustomerIdValidator));
        // etc.

        InitialDialogId = nameof(WaterfallDialog);
    }
}

I the code for validation in a separate class (hence the ICustomerValidator )

public class CustomerValidator : ICustomerValidator
{
    public async Task<bool> CustomerIdValidator(PromptValidatorContext<string> promptContext, CancellationToken cancellationToken)
    {
        // example
        return promptContext.Context.Activity.Text == "100";
    }
}

This all works fine. But how do I write a unit test solely for the CustomerValidator class?

Answer 1

Prompt validators are not meant to be called directly, even in tests. They are meant to be tested indirectly using test flow as seen in PromptValidatorContextTests , or by using a dialog test client.