Add a module to the test suite which contains all of the other ported modules

src/allmydata/test/python3_tests.py

@@ -0,0 +1,37 @@
+"""
+This module defines the subset of the full test suite which is expected to
+pass on Python 3 in a way which makes that suite discoverable by trial.
+
+This module has been ported to Python 3.
+"""
+
+from __future__ import unicode_literals
+from __future__ import absolute_import
+from __future__ import division
+from __future__ import print_function
+
+from future.utils import PY2
+if PY2:
+    from builtins import filter, map, zip, ascii, chr, hex, input, next, oct, open, pow, round, super, bytes, dict, list, object, range, str, max, min  # noqa: F401
+
+from twisted.python.reflect import (
+    namedModule,
+)
+from twisted.trial.runner import (
+    TestLoader,
+)
+from twisted.trial.unittest import (
+    TestSuite,
+)
+
+from allmydata.util._python3 import (
+    PORTED_TEST_MODULES,
+)
+
+def testSuite():
+    loader = TestLoader()
+    return TestSuite(list(
+        loader.loadModule(namedModule(module))
+        for module
+        in PORTED_TEST_MODULES
+    ))

src/allmydata/util/_python3.py

@@ -1,6 +1,15 @@
 """
 Track the port to Python 3.
 
+The two easiest ways to run the part of the test suite which is expected to
+pass on Python 3 are::
+
+    $ tox -e py36
+
+and::
+
+    $ trial allmydata.test.python3_tests
+
 This module has been ported to Python 3.
 """
 
@@ -71,7 +80,3 @@ PORTED_TEST_MODULES = [
     "allmydata.test.test_util",
     "allmydata.test.test_version",
 ]
-
-if __name__ == '__main__':
-    from subprocess import check_call
-    check_call(["trial"] + PORTED_TEST_MODULES)