Issue #26807: mock_open 'files' no longer error on readline at end of file.

Patch from Yolanda Robla.

Backports: 9549a3e3d4be2a15c222996abff8cb97180ee9be
Signed-off-by: Chris Withers <chris@withers.org>

1 files changed, 15 insertions, 1 deletions

diff --git a/mock/tests/testmock.py b/mock/tests/testmock.py
index e981f2c..f5e0b79 100644
--- a/mock/tests/testmock.py
+++ b/mock/tests/testmock.py
@@ -1503,7 +1503,21 @@ class MockTest(unittest.TestCase):
         second = mopen().readline()
         self.assertEqual('abc', first)
         self.assertEqual('abc', second)
- 
+
+
+    def test_mock_open_after_eof(self):
+        # read, readline and readlines should work after end of file.
+        _open = mock.mock_open(read_data='foo')
+        h = _open('bar')
+        h.read()
+        self.assertEqual('', h.read())
+        self.assertEqual('', h.read())
+        self.assertEqual('', h.readline())
+        self.assertEqual('', h.readline())
+        self.assertEqual([], h.readlines())
+        self.assertEqual([], h.readlines())
+
+
     def test_mock_parents(self):
         for Klass in Mock, MagicMock:
             m = Klass()