add mrbtest verbose mode ('-v' option)

test/assert.rb

@@ -23,6 +23,7 @@ end
 #       which will be tested by this
 #       assertion
 def assert(str = 'Assertion failed', iso = '')
+  print(str, (iso != '' ? " [#{iso}]" : ''), ' : ') if $mrbtest_verbose
   begin
     if(!yield)
       $asserts.push(assertion_string('Fail: ', str, iso))
@@ -37,6 +38,7 @@ def assert(str = 'Assertion failed', iso = '')
     $kill_test += 1
     print('X')
   end
+  print("\n") if $mrbtest_verbose
 end
 
 ##

test/driver.c

@@ -36,7 +36,7 @@ check_error(mrb_state *mrb)
 }
 
 int
-main(void)
+main(int argc, char **argv)
 {
   mrb_state *mrb;
   mrb_value return_value;
@@ -52,6 +52,11 @@ main(void)
     return EXIT_FAILURE;
   }
 
+  if (argc == 2 && strncmp(argv[1], "-v", 2) == 0) {
+    printf("verbose mode: enable\n\n");
+    mrb_gv_set(mrb, mrb_intern(mrb, "$mrbtest_verbose"), mrb_true_value());
+  }
+
   mrb_init_mrbtest(mrb);
   /* evaluate the test */
   return_value = mrb_load_string(mrb, prog);