Add initial postprocess unit test thingy.

recipe_engine/third_party/expect_tests/handle_train.py

Index: recipe_engine/third_party/expect_tests/handle_train.py
diff --git a/recipe_engine/third_party/expect_tests/handle_train.py b/recipe_engine/third_party/expect_tests/handle_train.py
index b3eded73acb519106e85eb9e7f01eabde3c9a079..27747a47e7dac235af7acce5543c6674a09fabe8 100644
--- a/recipe_engine/third_party/expect_tests/handle_train.py
+++ b/recipe_engine/third_party/expect_tests/handle_train.py
@@ -9,6 +9,7 @@ import time
 
 from .type_definitions import DirSeen, Handler, MultiTest, Failure
 from .serialize import WriteNewData, DiffData, NonExistant, GetCurrentData
+from .handle_test import FailChecks
 
 
 ForcedWriteAction = collections.namedtuple('ForcedWriteAction', 'test')
@@ -66,7 +67,11 @@ class TrainHandler(Handler):
         else:
           put_next_stage(SchemaDiffWriteAction(test))
       else:
-        put_next_stage(NoAction(test))
+        failed_checks = [check for check in result.checks if not check.passed]
+        if failed_checks:
+          put_next_stage(FailChecks(test, failed_checks))
+        else:
+          put_next_stage(NoAction(test))
 
   class ResultStageHandler(Handler.ResultStageHandler):
     def __init__(self, opts):
@@ -96,6 +101,12 @@ class TrainHandler(Handler):
     def handle_DirSeen(self, dirseen):
       self.dirs_seen.add(dirseen.dir)
 
+    def handle_FailChecks(self, fc):
+      self._record_expected(fc.test, 'C')
+      self.normal_actions.append(
+        ('%r failed checks!\n' % fc.test.name) + fc.format(2))
+      return Failure()
+
     def handle_NoAction(self, result):
       self._record_expected(result.test, '.')
       self.verbose_actions.append('%s did not change' % result.test.name)