Enable strict coverage for step module

recipe_engine/loader.py

 # Copyright 2016 The LUCI Authors. All rights reserved.
 # Use of this source code is governed under the Apache License, Version 2.0
 # that can be found in the LICENSE file.
 
 import collections
 import imp
 import inspect
 import os
 import sys
 
@@ skipping 217 matching lines @@
     }
     """
     return {
       local_name: self.universe.load(pkg, name)
       for local_name, (pkg, name) in self.normalize_deps_spec(spec).iteritems()
     }
 
 
   def find_recipe(self, recipe):
     if ':' in recipe:
-      module_name, example = recipe.split(':')
-      #TODO(martinis) change to example == 'example' ? Technically a bug...
-      assert example.endswith('example')
-      subpath = os.path.join(self.package.module_dir, module_name)
-      if _is_recipe_module_dir(subpath):
-        recipe_path = os.path.join(subpath, 'example.py')
+      module_name, recipe_name = recipe.split(':')
+      module_dir = os.path.join(self.package.module_dir, module_name)
+      if _is_recipe_module_dir(module_dir):
+        if recipe_name.endswith('example'):
+          # TODO(martinis) change to example == 'example' ? Technically a bug...
+          recipe_path = os.path.join(module_dir, 'example.py')
+        elif recipe_name.startswith('tests/'):
+          recipe_path = os.path.join(
+              module_dir, 'tests', recipe_name[len('tests/'):] + '.py')
+        else:
+          raise NoSuchRecipe(recipe)
     else:
       recipe_path = os.path.join(self.package.recipe_dir, recipe)+".py"
 
     if os.path.exists(recipe_path):
       return recipe_path
 
     raise NoSuchRecipe(recipe)
 
   def load_recipe(self, recipe, engine=None):
     """Given name of a recipe, loads and returns it as RecipeScript instance.
@@ skipping 51 matching lines @@
                    if not x.endswith(('.expected', '.resources'))]
         for file_name in (f for f in files if predicate(f)):
           file_path = os.path.join(root, file_name)
           yield file_path
 
     path = self.package.recipe_dir
     for recipe in scan_directory(
         path, lambda f: f.endswith('.py') and f[0] != '_'):
       yield recipe, recipe[len(path)+1:-len('.py')]
 
-    path = self.package.module_dir
-    for recipe in scan_directory(
-        path, lambda f: f.endswith('example.py')):
-      module_name = os.path.dirname(recipe)[len(path)+1:]
-      yield recipe, '%s:example' % module_name
+    for module_name in self.loop_over_recipe_modules():
+      module_dir = os.path.join(self.package.module_dir, module_name)
+
+      example_path = os.path.join(module_dir, 'example.py')
+      if os.path.exists(example_path):
+        yield example_path, '%s:example' % module_name
+
+      test_dir = os.path.join(module_dir, 'tests')
+      if os.path.exists(test_dir):
+        for recipe in scan_directory(test_dir, lambda f: f.endswith('.py')):
+          yield recipe, '%s:tests/%s' % (
+              module_name, recipe[len(test_dir)+1:-len('.py')])
 
   def loop_over_recipe_modules(self):
     """Yields the paths to all the modules that this view can see."""
     path = self.package.module_dir
     if os.path.isdir(path):
       for item in os.listdir(path):
         subpath = os.path.join(path, item)
         if _is_recipe_module_dir(subpath):
           yield os.path.basename(subpath)
 
@@ skipping 328 matching lines @@
   for k,v in toplevel_deps.iteritems():
     setattr(api, k, mapper.instantiate(v))
   return api
 
 
 def _resolve_requirement(req, engine):
   if req._typ == 'client':
     return engine._get_client(req._name)
   else:
     raise ValueError('Unknown requirement type [%s]' % (req._typ,))