Debugging.

lib/types.bzl

@@ -28,6 +28,15 @@ def _a_function():
 
 _a_function_type = type(_a_function)
 
+def _a_rule_impl(ctx):
+    return []
+
+_a_rule = rule(
+    implementation = _a_rule_impl,
+)
+
+_a_rule_type = type(_a_rule)
+
 def _is_list(v):
     """Returns True if v is an instance of a list.
 
@@ -148,7 +157,7 @@ def _is_partial(v):
       True if v was created by partial.make(), False otherwise.
     """
     return type(v) == _a_struct_type \
-        and hasattr(v, "function") and _is_function(v.function) \
+        and hasattr(v, "function") and (_is_function(v.function) or type(v.function) == _a_rule_type) \
         and hasattr(v, "args") and _is_tuple(v.args) \
         and hasattr(v, "kwargs") and _is_dict(v.kwargs)
 

lib/unittest.bzl

@@ -272,6 +272,8 @@ def _suite(name, *test_rules):
         test_name = "%s_test_%d" % (name, index)
         if types.is_partial(test_rule):
             partial.call(test_rule, name = test_name)
+        elif type(test_rule) == type(struct()):
+            fail("unexpected struct: {};\ntype(function): {};\ntype(args): {};\ntype(kwargs): {}".format(repr(test_rule), repr(type(test_rule.function)), repr(type(test_rule.args)), repr(type(test_rule.kwargs)) ))
         else:
             test_rule(name = test_name)
         test_names.append(test_name)