From ff767d07437ca41b95ebe0bed93b7c1a1795e7ff Mon Sep 17 00:00:00 2001
From: Bert Blommers <bblommers@users.noreply.github.com>
Date: Mon, 9 May 2022 13:01:31 +0000
Subject: [PATCH] DynamoDB - error when sending an integer as string (#5108)

---
 moto/dynamodb/exceptions.py                   |  6 ++++
 moto/dynamodb/models/__init__.py              | 10 ++++++
 .../exceptions/test_dynamodb_exceptions.py    | 34 ++++++++++++++++++-
 3 files changed, 49 insertions(+), 1 deletion(-)

diff --git a/moto/dynamodb/exceptions.py b/moto/dynamodb/exceptions.py
index 5f7bed4a1..b08448aa9 100644
--- a/moto/dynamodb/exceptions.py
+++ b/moto/dynamodb/exceptions.py
@@ -310,3 +310,9 @@ class StreamAlreadyEnabledException(JsonRESTError):
     def __init__(self):
         er = "com.amazonaws.dynamodb.v20111205#ResourceInUseException"
         super().__init__(er, "Cannot enable stream")
+
+
+class InvalidConversion(JsonRESTError):
+    def __init__(self):
+        er = "SerializationException"
+        super().__init__(er, "NUMBER_VALUE cannot be converted to String")
diff --git a/moto/dynamodb/models/__init__.py b/moto/dynamodb/models/__init__.py
index 68e726451..7d1614149 100644
--- a/moto/dynamodb/models/__init__.py
+++ b/moto/dynamodb/models/__init__.py
@@ -33,6 +33,7 @@ from moto.dynamodb.exceptions import (
     ResourceInUseException,
     StreamAlreadyEnabledException,
     MockValidationException,
+    InvalidConversion,
 )
 from moto.dynamodb.models.utilities import bytesize
 from moto.dynamodb.models.dynamo_type import DynamoType
@@ -646,6 +647,13 @@ class Table(CloudFormationModel):
                 if DynamoType(range_value).size() > RANGE_KEY_MAX_LENGTH:
                     raise RangeKeyTooLong
 
+    def _validate_item_types(self, item_attrs):
+        for key, value in item_attrs.items():
+            if type(value) == dict:
+                self._validate_item_types(value)
+            elif type(value) == int and key == "N":
+                raise InvalidConversion
+
     def put_item(
         self,
         item_attrs,
@@ -688,6 +696,8 @@ class Table(CloudFormationModel):
 
         self._validate_key_sizes(item_attrs)
 
+        self._validate_item_types(item_attrs)
+
         if expected is None:
             expected = {}
             lookup_range_value = range_value
diff --git a/tests/test_dynamodb/exceptions/test_dynamodb_exceptions.py b/tests/test_dynamodb/exceptions/test_dynamodb_exceptions.py
index fed98e4d9..1bb7b47f8 100644
--- a/tests/test_dynamodb/exceptions/test_dynamodb_exceptions.py
+++ b/tests/test_dynamodb/exceptions/test_dynamodb_exceptions.py
@@ -1,9 +1,11 @@
 import boto3
+import botocore
 import pytest
 import sure  # noqa # pylint: disable=unused-import
 from boto3.dynamodb.conditions import Key
 from botocore.exceptions import ClientError
-from moto import mock_dynamodb
+from unittest import SkipTest
+from moto import mock_dynamodb, settings
 
 table_schema = {
     "KeySchema": [{"AttributeName": "partitionKey", "KeyType": "HASH"}],
@@ -547,3 +549,33 @@ def test_update_item_non_existent_table():
     err = exc.value.response["Error"]
     assert err["Code"].should.equal("ResourceNotFoundException")
     assert err["Message"].should.equal("Requested resource not found")
+
+
+@mock_dynamodb
+def test_put_item_wrong_datatype():
+    if settings.TEST_SERVER_MODE:
+        raise SkipTest("Unable to mock a session with Config in ServerMode")
+    session = botocore.session.Session()
+    config = botocore.client.Config(parameter_validation=False)
+    client = session.create_client("dynamodb", region_name="us-east-1", config=config)
+    client.create_table(
+        TableName="test2",
+        KeySchema=[{"AttributeName": "mykey", "KeyType": "HASH"}],
+        AttributeDefinitions=[{"AttributeName": "mykey", "AttributeType": "N"}],
+        BillingMode="PAY_PER_REQUEST",
+    )
+    with pytest.raises(ClientError) as exc:
+        client.put_item(TableName="test2", Item={"mykey": {"N": 123}})
+    err = exc.value.response["Error"]
+    err["Code"].should.equal("SerializationException")
+    err["Message"].should.equal("NUMBER_VALUE cannot be converted to String")
+
+    # Same thing - but with a non-key, and nested
+    with pytest.raises(ClientError) as exc:
+        client.put_item(
+            TableName="test2",
+            Item={"mykey": {"N": "123"}, "nested": {"M": {"sth": {"N": 5}}}},
+        )
+    err = exc.value.response["Error"]
+    err["Code"].should.equal("SerializationException")
+    err["Message"].should.equal("NUMBER_VALUE cannot be converted to String")