Fix the exception that is raised when invalid JSON is encountered. (#8291)

tests/http/test_servlet.py

@@ -0,0 +1,80 @@
+# -*- coding: utf-8 -*-
+# Copyright 2020 The Matrix.org Foundation C.I.C.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+import json
+from io import BytesIO
+
+from mock import Mock
+
+from synapse.api.errors import SynapseError
+from synapse.http.servlet import (
+    parse_json_object_from_request,
+    parse_json_value_from_request,
+)
+
+from tests import unittest
+
+
+def make_request(content):
+    """Make an object that acts enough like a request."""
+    request = Mock(spec=["content"])
+
+    if isinstance(content, dict):
+        content = json.dumps(content).encode("utf8")
+
+    request.content = BytesIO(content)
+    return request
+
+
+class TestServletUtils(unittest.TestCase):
+    def test_parse_json_value(self):
+        """Basic tests for parse_json_value_from_request."""
+        # Test round-tripping.
+        obj = {"foo": 1}
+        result = parse_json_value_from_request(make_request(obj))
+        self.assertEqual(result, obj)
+
+        # Results don't have to be objects.
+        result = parse_json_value_from_request(make_request(b'["foo"]'))
+        self.assertEqual(result, ["foo"])
+
+        # Test empty.
+        with self.assertRaises(SynapseError):
+            parse_json_value_from_request(make_request(b""))
+
+        result = parse_json_value_from_request(make_request(b""), allow_empty_body=True)
+        self.assertIsNone(result)
+
+        # Invalid UTF-8.
+        with self.assertRaises(SynapseError):
+            parse_json_value_from_request(make_request(b"\xFF\x00"))
+
+        # Invalid JSON.
+        with self.assertRaises(SynapseError):
+            parse_json_value_from_request(make_request(b"foo"))
+
+        with self.assertRaises(SynapseError):
+            parse_json_value_from_request(make_request(b'{"foo": Infinity}'))
+
+    def test_parse_json_object(self):
+        """Basic tests for parse_json_object_from_request."""
+        # Test empty.
+        result = parse_json_object_from_request(
+            make_request(b""), allow_empty_body=True
+        )
+        self.assertEqual(result, {})
+
+        # Test not an object
+        with self.assertRaises(SynapseError):
+            parse_json_object_from_request(make_request(b'["foo"]'))