Merge branch 'master' into feature/dynamodb_item_limit

moto/dynamodb2/models/__init__.py

@@ -15,9 +15,15 @@ from moto.core.utils import unix_time
 from moto.core.exceptions import JsonRESTError
 from moto.dynamodb2.comparisons import get_filter_expression
 from moto.dynamodb2.comparisons import get_expected
-from moto.dynamodb2.exceptions import InvalidIndexNameError, ItemSizeTooLarge
+from moto.dynamodb2.exceptions import (
+    InvalidIndexNameError,
+    ItemSizeTooLarge,
+    ItemSizeToUpdateTooLarge,
+)
 from moto.dynamodb2.models.utilities import bytesize, attribute_is_list
 from moto.dynamodb2.models.dynamo_type import DynamoType
+from moto.dynamodb2.parsing.expressions import UpdateExpressionParser
+from moto.dynamodb2.parsing.validators import UpdateExpressionValidator
 
 
 class DynamoJsonEncoder(json.JSONEncoder):
@@ -153,7 +159,10 @@ class Item(BaseModel):
                     if "." in key and attr not in self.attrs:
                         raise ValueError  # Setting nested attr not allowed if first attr does not exist yet
                     elif attr not in self.attrs:
-                        self.attrs[attr] = dyn_value  # set new top-level attribute
+                        try:
+                            self.attrs[attr] = dyn_value  # set new top-level attribute
+                        except ItemSizeTooLarge:
+                            raise ItemSizeToUpdateTooLarge()
                     else:
                         self.attrs[attr].set(
                             ".".join(key.split(".")[1:]), dyn_value, list_index
@@ -1208,6 +1217,13 @@ class DynamoDBBackend(BaseBackend):
     ):
         table = self.get_table(table_name)
 
+        # Support spaces between operators in an update expression
+        # E.g. `a = b + c` -> `a=b+c`
+        if update_expression:
+            # Parse expression to get validation errors
+            update_expression_ast = UpdateExpressionParser.make(update_expression)
+            update_expression = re.sub(r"\s*([=\+-])\s*", "\\1", update_expression)
+
         if all([table.hash_key_attr in key, table.range_key_attr in key]):
             # Covers cases where table has hash and range keys, ``key`` param
             # will be a dict
@@ -1250,6 +1266,12 @@ class DynamoDBBackend(BaseBackend):
             item = table.get_item(hash_value, range_value)
 
         if update_expression:
+            UpdateExpressionValidator(
+                update_expression_ast,
+                expression_attribute_names=expression_attribute_names,
+                expression_attribute_values=expression_attribute_values,
+                item=item,
+            ).validate()
             item.update(
                 update_expression,
                 expression_attribute_names,