Ruby Challenges - Sudoku Validator

[r00k (Ben Orenstein)]

Continuing the discussion from New trail: Ruby Challenges:

@pdbradley

I have a question about the first sudoku challenge on the ruby trail.

There is a test for invalid sudoku challenges, and since this came baked into the project files I don’t think we should alter it much. But how is the Validator class supposed to know, and why should it know, the name of the file? The expected error message from the Validator class is expected to give that, but all that is supplied to the Validator class is a string.

What am I missing?

Hi Philip!

I think you might be misreading the expectation.

It looks like this:

 expect(result).to(
          eq("This sudoku is invalid."),
          "Expected #{fixture} to be invalid but it wasn't."
        )

The second argument to to is a string that provides a custom failure message when the expectation is not satisfied.

So, this code says “result should be equal to ‘This sudoku is invalid.’, but if it’s not, output the string 'Expected #{fixture_name} to be invalid but it wasnt.”.

In other words, the Validator does not know, and should not care about the name of the file.

Does that make sense?

More info on custom error messages: https://www.relishapp.com/rspec/rspec-expectations/v/3-2/docs/customized-message