Add test + release notes

AUTHORS.rst

@@ -79,6 +79,7 @@ their individual contributions.
 * `James Lamb <https://github.com/jameslamb>`_
 * `Jenny Rouleau <https://github.com/jennyrou>`_
 * `Jens Heinrich <https://github.com/JensHeinrich>`_
+* `Jens Tröger <https://github.com/jenstroeger>`_
 * `Jeremy Thurgood <https://github.com/jerith>`_
 * `J.J. Green <http://soliton.vm.bytemark.co.uk/pub/jjg/>`_
 * `JP Viljoen <https://github.com/froztbyte>`_ (froztbyte@froztbyte.net)

hypothesis-python/RELEASE.rst

@@ -0,0 +1,8 @@
+RELEASE_TYPE: minor
+
+This release adds an optional ``domains=`` parameter to the
+:func:`~hypothesis.strategies.emails` strategy, and excludes
+the special-use :wikipedia:`.arpa` domain from the default
+strategy (:issue:`3567`).
+
+Thanks to Jens Tröger for reporting and fixing this bug!

hypothesis-python/src/hypothesis/strategies/_internal/core.py

@@ -2014,28 +2014,28 @@ def deferred(definition: Callable[[], SearchStrategy[Ex]]) -> SearchStrategy[Ex]
 
 def domains():
     import hypothesis.provisional
+
     return hypothesis.provisional.domains()
 
 
 @defines_strategy(force_reusable_values=True)
-def emails(*, domains: SearchStrategy[str] = LazyStrategy(domains, (), {})) -> SearchStrategy[str]:
+def emails(
+    *, domains: SearchStrategy[str] = LazyStrategy(domains, (), {})
+) -> SearchStrategy[str]:
     """A strategy for generating email addresses as unicode strings. The
     address format is specified in :rfc:`5322#section-3.4.1`. Values shrink
     towards shorter local-parts and host domains.
 
     If ``domains`` is given then it must be a strategy that generates domain
-    names for the emails. By default, the internal :func:`hypothesis.provisional.domains` strategy
-    is used that does *not* produce any `special-use domain names
-    <https://www.iana.org/assignments/special-use-domain-names/special-use-domain-names.xhtml>`_
-    (which yield invalid email addresses).
+    names for the emails, defaulting to :func:`~hypothesis.provisional.domains`.
 
     This strategy is useful for generating "user data" for tests, as
     mishandling of email addresses is a common source of bugs.
     """
     local_chars = string.ascii_letters + string.digits + "!#$%&'*+-/=^_`{|}~"
     local_part = text(local_chars, min_size=1, max_size=64)
     # TODO: include dot-atoms, quoted strings, escaped chars, etc in local part
-    return builds("{}@{}".format, local_part, domains()).filter(
+    return builds("{}@{}".format, local_part, domains).filter(
         lambda addr: len(addr) <= 254
     )
 

hypothesis-python/tests/nocover/test_emails.py

@@ -9,13 +9,19 @@
 # obtain one at https://mozilla.org/MPL/2.0/.
 
 from hypothesis import given
-from hypothesis.strategies import emails
+from hypothesis.strategies import emails, just
 
 
 @given(emails())
-def test_is_valid_email(address):
+def test_is_valid_email(address: str):
     local, at_, domain = address.rpartition("@")
     assert len(address) <= 254
     assert at_ == "@"
     assert local
     assert domain
+    assert not domain.lower().endswith(".arpa")
+
+
+@given(emails(domains=just("mydomain.com")))
+def test_can_restrict_email_domains(address: str):
+    assert address.endswith("@mydomain.com")