Complain if a scenario has no THENs

1 files changed, 15 insertions, 0 deletions

diff --git a/yarn b/yarn
index ce0b9cb..3bb26e8 100755
--- a/yarn
+++ b/yarn
@@ -108,6 +108,7 @@ class YarnRunner(cliapp.Application):
                 'step %Index(step,steps): %String(step_name)')
 
         scenarios, implementations = self.parse_scenarios(args)
+        self.check_for_thens(scenarios)
         self.connect_implementations(scenarios, implementations)
         shell_prelude = self.load_shell_libraries()
 
@@ -157,6 +158,20 @@ class YarnRunner(cliapp.Application):
 
         return block_parser.scenarios, block_parser.implementations
 
+    def check_for_thens(self, scenarios):
+        no_thens = []
+        for scenario in scenarios:
+            for step in scenario.steps:
+                if step.what == 'THEN':
+                    break
+            else:
+                no_thens.append(scenario)
+
+        if no_thens:
+            raise cliapp.AppException(
+                'Some scenarios have no THENs:\n%s' %
+                ''.join('  "%s"\n' % s.name for s in scenarios))
+
     def connect_implementations(self, scenarios, implementations):
         for scenario in scenarios:
             for step in scenario.steps: