tests: Reproduer for overriding existing files

Signed-off-by: Jakub Jelen <jjelen@redhat.com>

Author: Jakuje

tests/unit/sftp_test.py

@@ -50,6 +50,21 @@ def dst_path(file_paths_pair):
     return path
 
 
+@pytest.fixture
+def other_payload():
+    """Generate a binary test payload."""
+    uuid_name = uuid.uuid4()
+    return 'Original content: {name!s}'.format(name=uuid_name).encode()
+
+
+@pytest.fixture
+def pre_existing_dst_path(dst_path, other_payload):
+    """Return a data destination path."""
+    dst_path.write_bytes(other_payload)
+    assert dst_path.exists()
+    return dst_path
+
+
 def test_make_sftp(sftp_session):
     """Smoke-test SFTP instance creation."""
     assert sftp_session
@@ -67,6 +82,12 @@ def test_get(dst_path, src_path, sftp_session, transmit_payload):
     assert dst_path.read_bytes() == transmit_payload
 
 
+def test_get_existing(pre_existing_dst_path, src_path, sftp_session, transmit_payload):
+    """Check that SFTP file download works when target file exists."""
+    sftp_session.get(str(src_path), str(pre_existing_dst_path))
+    assert pre_existing_dst_path.read_bytes() == transmit_payload
+
+
 @pytest.fixture
 def large_payload():
     """Generate a large 1025 byte (1024 + 1B) test payload."""