I remember writing a small .NET test library for that exact problem - You could pass in a lambda with a complex condition, and it evaluated every piece of the expression separately and pretty printed what part of the condition failed.

So essentially you could write

     Assert(()=>width>0 && x + width < screenWidth)

And you would get:

      Assertion failed: 
      x is 1500
      width is 600
      screenWidth is 1920

It used Expression to do the magic. Amazing debug messages. No moralizing required.

This was a huge boon for us as it was a legacy codebase and we ran tens of thousands of automated tests and it was really difficult to figure out why they failed.