FileCopier: capture exceptions

Use ForkExecutor to capture exceptions instead of showing
a full traceback. FileCopier callers will now be responsible
for displaying relevant exception messages.

Bug: https://bugs.gentoo.org/699400
Signed-off-by: Zac Medico <zmedico@gentoo.org>

1 files changed, 44 insertions, 0 deletions

diff --git a/lib/portage/tests/util/test_file_copier.py b/lib/portage/tests/util/test_file_copier.py
new file mode 100644
index 000000000..01dfba494
--- /dev/null
+++ b/lib/portage/tests/util/test_file_copier.py
@@ -0,0 +1,44 @@
+# Copyright 2019 Gentoo Authors
+# Distributed under the terms of the GNU General Public License v2
+
+import errno
+import os
+import shutil
+import tempfile
+
+from portage.tests import TestCase
+from portage.util._async.FileCopier import FileCopier
+from portage.util._eventloop.global_event_loop import global_event_loop
+
+
+class FileCopierTestCase(TestCase):
+
+	def testFileCopier(self):
+		loop = global_event_loop()
+		tempdir = tempfile.mkdtemp()
+		try:
+
+			# regular successful copy
+			src_path = os.path.join(tempdir, 'src')
+			dest_path = os.path.join(tempdir, 'dest')
+			content = b'foo'
+			with open(src_path, 'wb') as f:
+				f.write(content)
+			copier = FileCopier(src_path=src_path, dest_path=dest_path, scheduler=loop)
+			copier.start()
+			loop.run_until_complete(copier.async_wait())
+			self.assertEqual(copier.returncode, 0)
+			copier.future.result()
+			with open(dest_path, 'rb') as f:
+				self.assertEqual(f.read(), content)
+
+			# failure due to nonexistent src_path
+			src_path = os.path.join(tempdir, 'does-not-exist')
+			copier = FileCopier(src_path=src_path, dest_path=dest_path, scheduler=loop)
+			copier.start()
+			loop.run_until_complete(copier.async_wait())
+			self.assertEqual(copier.returncode, 1)
+			self.assertEqual(copier.future.exception().errno, errno.ENOENT)
+			self.assertEqual(copier.future.exception().filename, src_path.encode('utf8'))
+		finally:
+			shutil.rmtree(tempdir)