DynamoDB - Throw exception when updating key using SET operation (#4245)

moto/dynamodb2/exceptions.py

@@ -190,6 +190,17 @@ class TransactionCanceledException(ValueError):
 
 class EmptyKeyAttributeException(MockValidationException):
     empty_str_msg = "One or more parameter values were invalid: An AttributeValue may not contain an empty string"
+    # AWS has a different message for empty index keys
+    empty_index_msg = "One or more parameter values are not valid. The update expression attempted to update a secondary index key to a value that is not supported. The AttributeValue for a key attribute cannot contain an empty string value."
 
-    def __init__(self):
-        super(EmptyKeyAttributeException, self).__init__(self.empty_str_msg)
+    def __init__(self, key_in_index=False):
+        super(EmptyKeyAttributeException, self).__init__(
+            self.empty_index_msg if key_in_index else self.empty_str_msg
+        )
+
+
+class UpdateHashRangeKeyException(MockValidationException):
+    msg = "One or more parameter values were invalid: Cannot update attribute {}. This attribute is part of the key"
+
+    def __init__(self, key_name):
+        super(UpdateHashRangeKeyException, self).__init__(self.msg.format(key_name))

moto/dynamodb2/parsing/validators.py

@@ -13,6 +13,7 @@ from moto.dynamodb2.exceptions import (
     InvalidUpdateExpressionInvalidDocumentPath,
     ProvidedKeyDoesNotExist,
     EmptyKeyAttributeException,
+    UpdateHashRangeKeyException,
 )
 from moto.dynamodb2.models import DynamoType
 from moto.dynamodb2.parsing.ast_nodes import (
@@ -337,7 +338,22 @@ class EmptyStringKeyValueValidator(DepthFirstTraverser):
             and val_node.type in ["S", "B"]
             and key in self.key_attributes
         ):
-            raise EmptyKeyAttributeException
+            raise EmptyKeyAttributeException(key_in_index=True)
+        return node
+
+
+class UpdateHashRangeKeyValidator(DepthFirstTraverser):
+    def __init__(self, table_key_attributes):
+        self.table_key_attributes = table_key_attributes
+
+    def _processing_map(self):
+        return {UpdateExpressionPath: self.check_for_hash_or_range_key}
+
+    def check_for_hash_or_range_key(self, node):
+        """Check that hash and range keys are not updated"""
+        key_to_update = node.children[0].children[0]
+        if key_to_update in self.table_key_attributes:
+            raise UpdateHashRangeKeyException(key_to_update)
         return node
 
 
@@ -386,6 +402,7 @@ class UpdateExpressionValidator(Validator):
     def get_ast_processors(self):
         """Get the different processors that go through the AST tree and processes the nodes."""
         processors = [
+            UpdateHashRangeKeyValidator(self.table.table_key_attrs),
             ExpressionAttributeValueProcessor(self.expression_attribute_values),
             ExpressionAttributeResolvingProcessor(
                 self.expression_attribute_names, self.item

tests/test_dynamodb2/test_dynamodb.py

@@ -5527,6 +5527,54 @@ def test_gsi_key_can_be_updated():
     item["main_key"].should.equal({"S": "testkey1"})
 
 
+@mock_dynamodb2
+def test_gsi_key_cannot_be_empty():
+    name = "TestTable"
+    conn = boto3.client("dynamodb", region_name="eu-west-2")
+    conn.create_table(
+        TableName=name,
+        KeySchema=[{"AttributeName": "main_key", "KeyType": "HASH"}],
+        AttributeDefinitions=[
+            {"AttributeName": "main_key", "AttributeType": "S"},
+            {"AttributeName": "index_key", "AttributeType": "S"},
+        ],
+        ProvisionedThroughput={"ReadCapacityUnits": 5, "WriteCapacityUnits": 5},
+        GlobalSecondaryIndexes=[
+            {
+                "IndexName": "test_index",
+                "KeySchema": [{"AttributeName": "index_key", "KeyType": "HASH"}],
+                "Projection": {"ProjectionType": "ALL",},
+                "ProvisionedThroughput": {
+                    "ReadCapacityUnits": 1,
+                    "WriteCapacityUnits": 1,
+                },
+            }
+        ],
+    )
+
+    conn.put_item(
+        TableName=name,
+        Item={
+            "main_key": {"S": "testkey1"},
+            "extra_data": {"S": "testdata"},
+            "index_key": {"S": "indexkey1"},
+        },
+    )
+
+    with pytest.raises(ClientError) as ex:
+        conn.update_item(
+            TableName=name,
+            Key={"main_key": {"S": "testkey1"}},
+            UpdateExpression="set index_key=:new_index_key",
+            ExpressionAttributeValues={":new_index_key": {"S": ""}},
+        )
+    err = ex.value.response["Error"]
+    err["Code"].should.equal("ValidationException")
+    err["Message"].should.equal(
+        "One or more parameter values are not valid. The update expression attempted to update a secondary index key to a value that is not supported. The AttributeValue for a key attribute cannot contain an empty string value."
+    )
+
+
 @mock_dynamodb2
 def test_create_backup_for_non_existent_table_raises_error():
     client = boto3.client("dynamodb", "us-east-1")

tests/test_dynamodb2/test_dynamodb_table_with_range_key.py

@@ -14,6 +14,7 @@ import pytest
 from moto import mock_dynamodb2, mock_dynamodb2_deprecated
 from boto.exception import JSONResponseError
 from tests.helpers import requires_boto_gte
+from uuid import uuid4
 
 try:
     from boto.dynamodb2.fields import GlobalAllIndex, HashKey, RangeKey, AllIndex
@@ -2283,3 +2284,48 @@ def test_scan_by_index():
     assert last_eval_key["id"]["S"] == "1"
     assert last_eval_key["range_key"]["S"] == "1"
     assert last_eval_key["lsi_range_key"]["S"] == "1"
+
+
+@mock_dynamodb2
+@pytest.mark.parametrize("create_item_first", [False, True])
+@pytest.mark.parametrize(
+    "expression", ["set h=:New", "set r=:New", "set x=:New, r=:New"]
+)
+def test_update_item_throws_exception_when_updating_hash_or_range_key(
+    create_item_first, expression
+):
+    client = boto3.client("dynamodb", region_name="ap-northeast-3")
+    table_name = "testtable_3877"
+
+    client.create_table(
+        TableName=table_name,
+        KeySchema=[
+            {"AttributeName": "h", "KeyType": "HASH"},
+            {"AttributeName": "r", "KeyType": "RANGE"},
+        ],
+        AttributeDefinitions=[
+            {"AttributeName": "h", "AttributeType": "S"},
+            {"AttributeName": "r", "AttributeType": "S"},
+        ],
+    )
+
+    initial_val = str(uuid4())
+
+    if create_item_first:
+        client.put_item(
+            TableName=table_name, Item={"h": {"S": initial_val}, "r": {"S": "1"}},
+        )
+
+    # Updating the HASH key should fail
+    with pytest.raises(ClientError) as ex:
+        client.update_item(
+            TableName=table_name,
+            Key={"h": {"S": initial_val}, "r": {"S": "1"}},
+            UpdateExpression=expression,
+            ExpressionAttributeValues={":New": {"S": "2"}},
+        )
+    err = ex.value.response["Error"]
+    err["Code"].should.equal("ValidationException")
+    err["Message"].should.match(
+        r"One or more parameter values were invalid: Cannot update attribute (r|h). This attribute is part of the key"
+    )

tests/test_dynamodb2/test_dynamodb_validation.py

@@ -20,9 +20,9 @@ from moto.dynamodb2.parsing.validators import UpdateExpressionValidator
 
 
 def test_valid_update_expression(table):
-    update_expression = "set forum_name=:NewName, forum_type=:NewType"
+    update_expression = "set forum_desc=:Desc, forum_type=:NewType"
     update_expression_values = {
-        ":NewName": {"S": "AmazingForum"},
+        ":Desc": {"S": "AmazingForum"},
         ":NewType": {"S": "BASIC"},
     }
     update_expression_ast = UpdateExpressionParser.make(update_expression)
@@ -42,27 +42,6 @@ def test_valid_update_expression(table):
     ).validate()
 
 
-def test_validation_of_empty_string_key_val(table):
-    with pytest.raises(EmptyKeyAttributeException):
-        update_expression = "set forum_name=:NewName"
-        update_expression_values = {":NewName": {"S": ""}}
-        update_expression_ast = UpdateExpressionParser.make(update_expression)
-        item = Item(
-            hash_key=DynamoType({"S": "forum_name"}),
-            hash_key_type="TYPE",
-            range_key=None,
-            range_key_type=None,
-            attrs={"forum_name": {"S": "hello"}},
-        )
-        UpdateExpressionValidator(
-            update_expression_ast,
-            expression_attribute_names=None,
-            expression_attribute_values=update_expression_values,
-            item=item,
-            table=table,
-        ).validate()
-
-
 def test_validation_of_update_expression_with_keyword(table):
     try:
         update_expression = "SET myNum = path + :val"