1 files changed, 107 insertions, 0 deletions
diff --git a/Lib/test/json_tests/test_scanstring.py b/Lib/test/json_tests/test_scanstring.py
new file mode 100644
index 0000000000..d503851e56
--- /dev/null
+++ b/Lib/test/json_tests/test_scanstring.py
@@ -0,0 +1,107 @@
+import sys
+import decimal
+from unittest import TestCase
+
+import json
+import json.decoder
+
+class TestScanString(TestCase):
+    def test_py_scanstring(self):
+        self._test_scanstring(json.decoder.py_scanstring)
+
+    def test_c_scanstring(self):
+        if json.decoder.c_scanstring is not None:
+            self._test_scanstring(json.decoder.c_scanstring)
+
+    def _test_scanstring(self, scanstring):
+        self.assertEqual(
+            scanstring('"z\\ud834\\udd20x"', 1, True),
+            ('z\U0001d120x', 16))
+
+        if sys.maxunicode == 65535:
+            self.assertEqual(
+                scanstring('"z\U0001d120x"', 1, True),
+                ('z\U0001d120x', 6))
+        else:
+            self.assertEqual(
+                scanstring('"z\U0001d120x"', 1, True),
+                ('z\U0001d120x', 5))
+
+        self.assertEqual(
+            scanstring('"\\u007b"', 1, True),
+            ('{', 8))
+
+        self.assertEqual(
+            scanstring('"A JSON payload should be an object or array, not a string."', 1, True),
+            ('A JSON payload should be an object or array, not a string.', 60))
+
+        self.assertEqual(
+            scanstring('["Unclosed array"', 2, True),
+            ('Unclosed array', 17))
+
+        self.assertEqual(
+            scanstring('["extra comma",]', 2, True),
+            ('extra comma', 14))
+
+        self.assertEqual(
+            scanstring('["double extra comma",,]', 2, True),
+            ('double extra comma', 21))
+
+        self.assertEqual(
+            scanstring('["Comma after the close"],', 2, True),
+            ('Comma after the close', 24))
+
+        self.assertEqual(
+            scanstring('["Extra close"]]', 2, True),
+            ('Extra close', 14))
+
+        self.assertEqual(
+            scanstring('{"Extra comma": true,}', 2, True),
+            ('Extra comma', 14))
+
+        self.assertEqual(
+            scanstring('{"Extra value after close": true} "misplaced quoted value"', 2, True),
+            ('Extra value after close', 26))
+
+        self.assertEqual(
+            scanstring('{"Illegal expression": 1 + 2}', 2, True),
+            ('Illegal expression', 21))
+
+        self.assertEqual(
+            scanstring('{"Illegal invocation": alert()}', 2, True),
+            ('Illegal invocation', 21))
+
+        self.assertEqual(
+            scanstring('{"Numbers cannot have leading zeroes": 013}', 2, True),
+            ('Numbers cannot have leading zeroes', 37))
+
+        self.assertEqual(
+            scanstring('{"Numbers cannot be hex": 0x14}', 2, True),
+            ('Numbers cannot be hex', 24))
+
+        self.assertEqual(
+            scanstring('[[[[[[[[[[[[[[[[[[[["Too deep"]]]]]]]]]]]]]]]]]]]]', 21, True),
+            ('Too deep', 30))
+
+        self.assertEqual(
+            scanstring('{"Missing colon" null}', 2, True),
+            ('Missing colon', 16))
+
+        self.assertEqual(
+            scanstring('{"Double colon":: null}', 2, True),
+            ('Double colon', 15))
+
+        self.assertEqual(
+            scanstring('{"Comma instead of colon", null}', 2, True),
+            ('Comma instead of colon', 25))
+
+        self.assertEqual(
+            scanstring('["Colon instead of comma": false]', 2, True),
+            ('Colon instead of comma', 25))
+
+        self.assertEqual(
+            scanstring('["Bad value", truth]', 2, True),
+            ('Bad value', 12))
+
+    def test_overflow(self):
+        self.assertRaises(OverflowError, json.decoder.scanstring, b"xxx", sys.maxsize+1)