1 files changed, 41 insertions, 0 deletions
diff --git a/setuptools/tests/test_test.py b/setuptools/tests/test_test.py
new file mode 100644
index 00000000..8b8d9e6c
--- /dev/null
+++ b/setuptools/tests/test_test.py
@@ -0,0 +1,41 @@
+import pytest
+from jaraco import path
+
+from setuptools.command.test import test
+from setuptools.dist import Distribution
+
+from .textwrap import DALS
+
+
+@pytest.mark.usefixtures('tmpdir_cwd')
+def test_tests_are_run_once(capfd):
+    params = dict(
+        name='foo',
+        packages=['dummy'],
+    )
+    files = {
+        'setup.py':
+            'from setuptools import setup; setup('
+            + ','.join(f'{name}={params[name]!r}' for name in params)
+            + ')',
+        'dummy': {
+            '__init__.py': '',
+            'test_dummy.py': DALS(
+                """
+                import unittest
+                class TestTest(unittest.TestCase):
+                    def test_test(self):
+                        print('Foo')
+                """
+                ),
+            },
+    }
+    path.build(files)
+    dist = Distribution(params)
+    dist.script_name = 'setup.py'
+    cmd = test(dist)
+    cmd.ensure_finalized()
+    cmd.run()
+    out, err = capfd.readouterr()
+    assert out.endswith('Foo\n')
+    assert len(out.split('Foo')) == 2