Negative validation

[ma499]

I would like to have a build task that verifies that invalid files fail validation against a schema. The reason why I want to do this is that I am writing custom formats and validation patterns and want to prove they are correct.

I need this ASAP so am happy to implement in a fork and send a pull request but want to agree this with you so that it doesn't block my work. Else I'll have to use a local fork in my own project. I think I work nearby to you so we can meet up to discuss or else discuss on Skype.

[jahed]

So essentially you want an option to succeed the task when the validation fails? Sounds good to me. It should be straight forward.

I'm happy to discuss and merge a pull request when you're done.