Python bindings: raise proper exceptions for IO operations (#1313)

Signed-off-by: Jean-Christophe Morin <[email protected]>

src/py-opentimelineio/opentimelineio-bindings/otio_errorStatusHandler.cpp

@@ -50,9 +50,11 @@ ErrorStatusHandler::~ErrorStatusHandler() noexcept(false) {
     case ErrorStatus::JSON_PARSE_ERROR:
         throw py::value_error("JSON parse error while reading: " + details());
     case ErrorStatus::FILE_OPEN_FAILED:
-        throw py::value_error("failed to open file for reading: " + details());
+        PyErr_SetFromErrnoWithFilename(PyExc_OSError, details().c_str());
+        throw py::error_already_set();
     case ErrorStatus::FILE_WRITE_FAILED:
-        throw py::value_error("failed to open file for writing: " + details());
+        PyErr_SetFromErrnoWithFilename(PyExc_OSError, details().c_str());
+        throw py::error_already_set();
     case ErrorStatus::SCHEMA_VERSION_UNSUPPORTED:
         throw _UnsupportedSchemaException(full_details());
     case ErrorStatus::NOT_A_CHILD_OF:

tests/test_core.py

@@ -0,0 +1,52 @@
+# SPDX-License-Identifier: Apache-2.0
+# Copyright Contributors to the OpenTimelineIO project
+
+import sys
+import shutil
+import tempfile
+import unittest
+
+import opentimelineio as otio
+
+
+class TestCoreFunctions(unittest.TestCase):
+    def setUp(self):
+        self.tmpDir = tempfile.mkdtemp()
+
+    def tearDown(self):
+        shutil.rmtree(self.tmpDir)
+
+    def test_deserialize_json_from_file_errors(self):
+        """Verify that the bindings return the correct errors based on the errno"""
+        if sys.version_info[0] < 3:
+            excType = OSError
+        else:
+            excType = FileNotFoundError  # noqa: F821
+
+        with self.assertRaises(excType) as exc:
+            otio.core.deserialize_json_from_file('non-existent-file-here')
+        self.assertIsInstance(exc.exception, excType)
+
+    @unittest.skipUnless(not sys.platform.startswith("win"), "requires non Windows sytem")  # noqa
+    def test_serialize_json_to_file_errors_non_windows(self):
+        """Verify that the bindings return the correct errors based on the errno"""
+        if sys.version_info[0] < 3:
+            excType = OSError
+        else:
+            excType = IsADirectoryError  # noqa: F821
+
+        with self.assertRaises(excType) as exc:
+            otio.core.serialize_json_to_file({}, self.tmpDir)
+        self.assertIsInstance(exc.exception, excType)
+
+    @unittest.skipUnless(sys.platform.startswith("win"), "requires Windows")
+    def test_serialize_json_to_file_errors_windows(self):
+        """Verify that the bindings return the correct errors based on the errno"""
+        if sys.version_info[0] < 3:
+            excType = OSError
+        else:
+            excType = PermissionError  # noqa: F821
+
+        with self.assertRaises(excType) as exc:
+            otio.core.serialize_json_to_file({}, self.tmpDir)
+        self.assertIsInstance(exc.exception, excType)