#11731: simplify/enhance parser/generator API by introducing policy objects.
This new interface will also allow for future planned enhancements
in control over the parser/generator without requiring any additional
complexity in the parser/generator API.
Patch reviewed by Éric Araujo and Barry Warsaw.
diff --git a/Lib/test/test_email/test_policy.py b/Lib/test/test_email/test_policy.py
new file mode 100644
index 0000000..086ce40
--- /dev/null
+++ b/Lib/test/test_email/test_policy.py
@@ -0,0 +1,148 @@
+import types
+import unittest
+import email.policy
+
+class PolicyAPITests(unittest.TestCase):
+
+ longMessage = True
+
+ # These default values are the ones set on email.policy.default.
+ # If any of these defaults change, the docs must be updated.
+ policy_defaults = {
+ 'max_line_length': 78,
+ 'linesep': '\n',
+ 'must_be_7bit': False,
+ 'raise_on_defect': False,
+ }
+
+ # For each policy under test, we give here the values of the attributes
+ # that are different from the defaults for that policy.
+ policies = {
+ email.policy.Policy(): {},
+ email.policy.default: {},
+ email.policy.SMTP: {'linesep': '\r\n'},
+ email.policy.HTTP: {'linesep': '\r\n', 'max_line_length': None},
+ email.policy.strict: {'raise_on_defect': True},
+ }
+
+ def test_defaults(self):
+ for policy, changed_defaults in self.policies.items():
+ expected = self.policy_defaults.copy()
+ expected.update(changed_defaults)
+ for attr, value in expected.items():
+ self.assertEqual(getattr(policy, attr), value,
+ ("change {} docs/docstrings if defaults have "
+ "changed").format(policy))
+
+ def test_all_attributes_covered(self):
+ for attr in dir(email.policy.default):
+ if (attr.startswith('_') or
+ isinstance(getattr(email.policy.Policy, attr),
+ types.FunctionType)):
+ continue
+ else:
+ self.assertIn(attr, self.policy_defaults,
+ "{} is not fully tested".format(attr))
+
+ def test_policy_is_immutable(self):
+ for policy in self.policies:
+ for attr in self.policy_defaults:
+ with self.assertRaisesRegex(AttributeError, attr+".*read-only"):
+ setattr(policy, attr, None)
+ with self.assertRaisesRegex(AttributeError, 'no attribute.*foo'):
+ policy.foo = None
+
+ def test_set_policy_attrs_when_calledl(self):
+ testattrdict = { attr: None for attr in self.policy_defaults }
+ for policyclass in self.policies:
+ policy = policyclass.clone(**testattrdict)
+ for attr in self.policy_defaults:
+ self.assertIsNone(getattr(policy, attr))
+
+ def test_reject_non_policy_keyword_when_called(self):
+ for policyclass in self.policies:
+ with self.assertRaises(TypeError):
+ policyclass(this_keyword_should_not_be_valid=None)
+ with self.assertRaises(TypeError):
+ policyclass(newtline=None)
+
+ def test_policy_addition(self):
+ expected = self.policy_defaults.copy()
+ p1 = email.policy.default.clone(max_line_length=100)
+ p2 = email.policy.default.clone(max_line_length=50)
+ added = p1 + p2
+ expected.update(max_line_length=50)
+ for attr, value in expected.items():
+ self.assertEqual(getattr(added, attr), value)
+ added = p2 + p1
+ expected.update(max_line_length=100)
+ for attr, value in expected.items():
+ self.assertEqual(getattr(added, attr), value)
+ added = added + email.policy.default
+ for attr, value in expected.items():
+ self.assertEqual(getattr(added, attr), value)
+
+ def test_register_defect(self):
+ class Dummy:
+ def __init__(self):
+ self.defects = []
+ obj = Dummy()
+ defect = object()
+ policy = email.policy.Policy()
+ policy.register_defect(obj, defect)
+ self.assertEqual(obj.defects, [defect])
+ defect2 = object()
+ policy.register_defect(obj, defect2)
+ self.assertEqual(obj.defects, [defect, defect2])
+
+ class MyObj:
+ def __init__(self):
+ self.defects = []
+
+ class MyDefect(Exception):
+ pass
+
+ def test_handle_defect_raises_on_strict(self):
+ foo = self.MyObj()
+ defect = self.MyDefect("the telly is broken")
+ with self.assertRaisesRegex(self.MyDefect, "the telly is broken"):
+ email.policy.strict.handle_defect(foo, defect)
+
+ def test_handle_defect_registers_defect(self):
+ foo = self.MyObj()
+ defect1 = self.MyDefect("one")
+ email.policy.default.handle_defect(foo, defect1)
+ self.assertEqual(foo.defects, [defect1])
+ defect2 = self.MyDefect("two")
+ email.policy.default.handle_defect(foo, defect2)
+ self.assertEqual(foo.defects, [defect1, defect2])
+
+ class MyPolicy(email.policy.Policy):
+ defects = []
+ def register_defect(self, obj, defect):
+ self.defects.append(defect)
+
+ def test_overridden_register_defect_still_raises(self):
+ foo = self.MyObj()
+ defect = self.MyDefect("the telly is broken")
+ with self.assertRaisesRegex(self.MyDefect, "the telly is broken"):
+ self.MyPolicy(raise_on_defect=True).handle_defect(foo, defect)
+
+ def test_overriden_register_defect_works(self):
+ foo = self.MyObj()
+ defect1 = self.MyDefect("one")
+ my_policy = self.MyPolicy()
+ my_policy.handle_defect(foo, defect1)
+ self.assertEqual(my_policy.defects, [defect1])
+ self.assertEqual(foo.defects, [])
+ defect2 = self.MyDefect("two")
+ my_policy.handle_defect(foo, defect2)
+ self.assertEqual(my_policy.defects, [defect1, defect2])
+ self.assertEqual(foo.defects, [])
+
+ # XXX: Need subclassing tests.
+ # For adding subclassed objects, make sure the usual rules apply (subclass
+ # wins), but that the order still works (right overrides left).
+
+if __name__ == '__main__':
+ unittest.main()