User messages and errors

info(...)

Display an informational message.

It should be called with printf-like arguments.

warn(...)

Display a warning message.

It should be called with printf-like arguments.

skip(...)

Stops and ignore the test.

It can be called without arguments, or with printf-style arguments to display a message explaining why the test has been ignored.

err(...)

Make the test fail and display an error message.

It should be called with printf-like arguments.

panic(...)

Stops the execution of all the tests and display an error message.

It should be called with printf-like arguments.