Wrap sequence append type errors in JsonPointerException

jsonpointer.py

@@ -275,8 +275,9 @@ def _set_child(parent, part, value):
         elif isinstance(parent, Sequence) and part == '-':
             try:
                 parent.append(value)
-            except AttributeError as e:
-                # immutable sequences, such as tuples, can't be appended to
+            except (AttributeError, TypeError) as e:
+                # Immutable sequences can't be appended to; typed sequences
+                # can reject the value just like an indexed assignment.
                 raise JsonPointerException("Invalid assignment target: %s" % (e,))
         else:
             try:

tests.py

@@ -467,6 +467,34 @@ def test_set_create_off_by_default(self):
                           "/cat/name", "whiskers")
         self.assertEqual(doc, {})
 
+    def test_set_sequence_append_invalid_type(self):
+        for pointer, create in (("/items/0", False), ("/items/-", False),
+                                ("/items/-", True), ("/items/1", True)):
+            for inplace in (False, True):
+                with self.subTest(pointer=pointer, create=create, inplace=inplace):
+                    doc = {"items": bytearray([1])}
+                    with self.assertRaisesRegex(JsonPointerException, "Invalid assignment target:"):
+                        set_pointer(doc, pointer, "invalid", inplace=inplace, create=create)
+                    self.assertEqual(doc, {"items": bytearray([1])})
+
+    def test_set_create_sequence_append_invalid_child(self):
+        for pointer in ("/items/-/leaf", "/items/1/leaf"):
+            with self.subTest(pointer=pointer):
+                doc = {"items": bytearray([1])}
+                with self.assertRaisesRegex(JsonPointerException, "Invalid assignment target:"):
+                    set_pointer(doc, pointer, 7, create=True)
+                self.assertEqual(doc, {"items": bytearray([1])})
+
+    def test_set_sequence_append_valid_type(self):
+        for pointer, create in (("/items/-", False), ("/items/-", True),
+                                ("/items/1", True)):
+            for inplace in (False, True):
+                with self.subTest(pointer=pointer, create=create, inplace=inplace):
+                    doc = {"items": bytearray([1])}
+                    result = set_pointer(doc, pointer, 2, inplace=inplace, create=create)
+                    self.assertEqual(result, {"items": bytearray([1, 2])})
+                    self.assertEqual(doc, result if inplace else {"items": bytearray([1])})
+
 
 class AltTypesTests(unittest.TestCase):
     class Node(object):