Thanks for the feedback 🙂

With the following 'myclass' class:

classdef myclass
  properties
    id;
  endproperties
  methods
    function this = myclass (id)
      if (! nargin)
        print_usage ();
      endif
      this.id = id;
    endfunction
  endmethods
endclassdef

%!test myclass ("");
%!error myclass ();

the tests fail from the second time they are run:

>> test myclass
PASSES 2 out of 2 tests
>> test myclass
***** test myclass ("");
!!!!! test failed
class not found: myclass

and by calling the tests directly, it seems the issue is due to the fact that print_usage () errors (as there is no help text) and from there on, the class is not found any more.

>> clear all
>> myclass ("");
>> myclass ();
error: print_usage: 'myclass' not found
>> myclass ("");
error: class not found: myclass
error: called from
    myclass at line 14 column 15