tests: add cc files for testing oct files

Fixes Issue #181.

test/octfiles/test_all.m

@@ -0,0 +1,35 @@
+%% -*- texinfo -*-
+%% @defun test_all ()
+%% tests
+%%
+%% @example
+%% 42
+%% @result{} ans =  42
+%% @end example
+%%
+%% Note its not possible to call doctest from a doctest [1].
+%% Instead, we use octave BIST mechanism.
+%%
+%% [1] https://github.com/catch22/octave-doctest/issues/184
+%%
+%% @end defun
+
+function test_all()
+
+end
+
+%!test
+%! [numpass, numtests, ~] = doctest ('test_octfile_single_fcn');
+%! assert (numtests, 2)
+%! assert (numpass, 2)
+
+%!test
+%! % different behaviour with or without extension
+%! [dir, ~, ~] = fileparts (which ('test_octfile_multi.oct'));
+%! autoload ('test_subfcn1', fullfile (dir, 'test_octfile_multi.oct'));
+%! [numpass, numtests, ~] = doctest ('test_octfile_multi');
+%! assert (numtests, 1)
+%! assert (numpass, 1)
+%! [numpass, numtests, ~] = doctest ('test_octfile_multi.oct');
+%! assert (numtests, 4)
+%! assert (numpass, 4)

test/octfiles/test_octfile_multi.cc

@@ -0,0 +1,45 @@
+#include <octave/oct.h>
+
+DEFUN_DLD (test_octfile_multi, args, ,
+           "-*- texinfo -*-\n\
+@deftypefn  {} {} test_octfile_multi ()\n\
+Testing\n\
+\n\
+@example\n\
+a = 42\n\
+@result{} a = 42\n\
+@end example\n\
+@end deftypefn")
+{
+  return ovl (0);
+}
+
+DEFUN_DLD (test_subfcn1, args, ,
+           "-*- texinfo -*-\n\
+@deftypefn  {} {} test_subfcn1 ()\n\
+Testing\n\
+\n\
+@example\n\
+a = 43\n\
+@result{} a = 43\n\
+@end example\n\
+@end deftypefn")
+{
+  return ovl (0);
+}
+
+DEFUN_DLD (test_subfcn2, args, ,
+           "-*- texinfo -*-\n\
+@deftypefn  {} {} test_subfcn2 ()\n\
+Testing\n\
+\n\
+@example\n\
+a = 44\n\
+@result{} a = 44\n\
+a = a + 1\n\
+@result{} a = 45\n\
+@end example\n\
+@end deftypefn")
+{
+  return ovl (0);
+}

test/octfiles/test_octfile_single_fcn.cc

@@ -0,0 +1,17 @@
+#include <octave/oct.h>
+
+DEFUN_DLD (test_octfile_single_fcn, args, ,
+           "-*- texinfo -*-\n\
+@deftypefn  {} {} test_octfile_single_fcn ()\n\
+Testing\n\
+\n\
+@example\n\
+b = 42\n\
+@result{} b = 42\n\
+b = b + 1\n\
+@result{} b = 43\n\
+@end example\n\
+@end deftypefn")
+{
+  return ovl (0);
+}