DynamoDB (V1) - implement UpdateItem (#3926)

* DynamoDB (V1) - UpdateItem implementation

* DynamoDB (V1) - negative tests for UpdateItem

moto/dynamodb/models.py

@@ -38,6 +38,12 @@ class DynamoType(object):
     def __repr__(self):
         return "DynamoType: {0}".format(self.to_json())
 
+    def add(self, dyn_type):
+        if self.type == "SS":
+            self.value.append(dyn_type.value)
+        if self.type == "N":
+            self.value = str(int(self.value) + int(dyn_type.value))
+
     def to_json(self):
         return {self.type: self.value}
 
@@ -281,6 +287,20 @@ class Table(CloudFormationModel):
         except KeyError:
             return None
 
+    def update_item(self, hash_key, range_key, attr_updates):
+        item = self.get_item(hash_key, range_key)
+        if not item:
+            return None
+
+        for attr, update in attr_updates.items():
+            if update["Action"] == "PUT":
+                item.attrs[attr] = DynamoType(update["Value"])
+            if update["Action"] == "DELETE":
+                item.attrs.pop(attr)
+            if update["Action"] == "ADD":
+                item.attrs[attr].add(DynamoType(update["Value"]))
+        return item
+
     def get_cfn_attribute(self, attribute_name):
         from moto.cloudformation.exceptions import UnformattedGetAttTemplateException
 
@@ -360,5 +380,15 @@ class DynamoDBBackend(BaseBackend):
 
         return table.delete_item(hash_key, range_key)
 
+    def update_item(self, table_name, hash_key_dict, range_key_dict, attr_updates):
+        table = self.tables.get(table_name)
+        if not table:
+            return None
+
+        hash_key = DynamoType(hash_key_dict)
+        range_key = DynamoType(range_key_dict) if range_key_dict else None
+
+        return table.update_item(hash_key, range_key, attr_updates)
+
 
 dynamodb_backend = DynamoDBBackend()

moto/dynamodb/responses.py

@@ -275,3 +275,22 @@ class DynamoHandler(BaseResponse):
         else:
             er = "com.amazonaws.dynamodb.v20111205#ResourceNotFoundException"
             return self.error(er)
+
+    def update_item(self):
+        name = self.body["TableName"]
+        key = self.body["Key"]
+        hash_key = key["HashKeyElement"]
+        range_key = key.get("RangeKeyElement")
+        updates = self.body["AttributeUpdates"]
+        return_values = self.body.get("ReturnValues", "")  # noqa
+
+        item = dynamodb_backend.update_item(name, hash_key, range_key, updates)
+
+        if item:
+            item_dict = item.to_json()
+            item_dict["ConsumedCapacityUnits"] = 0.5
+
+            return dynamo_json_dump(item_dict)
+        else:
+            er = "com.amazonaws.dynamodb.v20111205#ResourceNotFoundException"
+            return self.error(er)

tests/test_dynamodb/test_server.py

@@ -1,4 +1,5 @@
 from __future__ import unicode_literals
+import json
 import sure  # noqa
 
 import moto.server as server
@@ -18,3 +19,169 @@ def test_table_list():
     headers = {"X-Amz-Target": "TestTable.ListTables"}
     res = test_client.get("/", headers=headers)
     res.data.should.contain(b"TableNames")
+
+
+def test_update_item():
+    backend = server.create_backend_app("dynamodb")
+    test_client = backend.test_client()
+
+    create_table(test_client)
+
+    headers, res = put_item(test_client)
+
+    # UpdateItem
+    headers["X-Amz-Target"] = "DynamoDB_20111205.UpdateItem"
+    request_body = {
+        "TableName": "Table1",
+        "Key": {
+            "HashKeyElement": {"S": "customer"},
+            "RangeKeyElement": {"N": "12341234"},
+        },
+        "AttributeUpdates": {"new_att": {"Value": {"SS": ["val"]}, "Action": "PUT"}},
+    }
+    res = test_client.post("/", headers=headers, json=request_body)
+
+    # UpdateItem
+    headers["X-Amz-Target"] = "DynamoDB_20111205.UpdateItem"
+    request_body = {
+        "TableName": "Table1",
+        "Key": {
+            "HashKeyElement": {"S": "customer"},
+            "RangeKeyElement": {"N": "12341234"},
+        },
+        "AttributeUpdates": {"new_n": {"Value": {"N": "42"}, "Action": "PUT"}},
+    }
+    res = test_client.post("/", headers=headers, json=request_body)
+    res = json.loads(res.data)
+
+    res["ConsumedCapacityUnits"].should.equal(0.5)
+    res["Attributes"].should.equal(
+        {
+            "hkey": "customer",
+            "name": "myname",
+            "rkey": "12341234",
+            "new_att": ["val"],
+            "new_n": "42",
+        }
+    )
+
+    # UpdateItem - multiples
+    headers["X-Amz-Target"] = "DynamoDB_20111205.UpdateItem"
+    request_body = {
+        "TableName": "Table1",
+        "Key": {
+            "HashKeyElement": {"S": "customer"},
+            "RangeKeyElement": {"N": "12341234"},
+        },
+        "AttributeUpdates": {
+            "new_n": {"Value": {"N": 7}, "Action": "ADD"},
+            "new_att": {"Value": {"S": "val2"}, "Action": "ADD"},
+            "name": {"Action": "DELETE"},
+        },
+    }
+    res = test_client.post("/", headers=headers, json=request_body)
+    res = json.loads(res.data)
+
+    res["ConsumedCapacityUnits"].should.equal(0.5)
+    res["Attributes"].should.equal(
+        {
+            "hkey": "customer",
+            "rkey": "12341234",
+            "new_att": ["val", "val2"],
+            "new_n": "49",
+        }
+    )
+
+    # GetItem
+    headers["X-Amz-Target"] = "DynamoDB_20111205.GetItem"
+    request_body = {
+        "TableName": "Table1",
+        "Key": {
+            "HashKeyElement": {"S": "customer"},
+            "RangeKeyElement": {"N": "12341234"},
+        },
+    }
+    res = test_client.post("/", headers=headers, json=request_body)
+    res = json.loads(res.data)
+    res["Item"].should.have.key("new_att").equal({"SS": ["val", "val2"]})
+    res["Item"].should.have.key("new_n").equal({"N": "49"})
+    res["Item"].shouldnt.have.key("name")
+
+
+def test_update_item_that_doesnt_exist():
+    backend = server.create_backend_app("dynamodb")
+    test_client = backend.test_client()
+
+    create_table(test_client)
+
+    # UpdateItem
+    headers = {"X-Amz-Target": "DynamoDB_20111205.UpdateItem"}
+    request_body = {
+        "TableName": "Table1",
+        "Key": {
+            "HashKeyElement": {"S": "customer"},
+            "RangeKeyElement": {"N": "12341234"},
+        },
+        "AttributeUpdates": {"new_att": {"Value": {"SS": ["val"]}, "Action": "PUT"}},
+    }
+    res = test_client.post("/", headers=headers, json=request_body)
+    res.status_code.should.equal(400)
+    json.loads(res.data).should.equal(
+        {"__type": "com.amazonaws.dynamodb.v20111205#ResourceNotFoundException"}
+    )
+
+
+def test_update_item_in_nonexisting_table():
+    backend = server.create_backend_app("dynamodb")
+    test_client = backend.test_client()
+
+    # UpdateItem
+    headers = {"X-Amz-Target": "DynamoDB_20111205.UpdateItem"}
+    request_body = {
+        "TableName": "nonexistent",
+        "Key": {
+            "HashKeyElement": {"S": "customer"},
+            "RangeKeyElement": {"N": "12341234"},
+        },
+        "AttributeUpdates": {"new_att": {"Value": {"SS": ["val"]}, "Action": "PUT"}},
+    }
+    res = test_client.post("/", headers=headers, json=request_body)
+    res.status_code.should.equal(400)
+    json.loads(res.data).should.equal(
+        {"__type": "com.amazonaws.dynamodb.v20111205#ResourceNotFoundException"}
+    )
+
+
+def put_item(test_client, rkey="12341234"):
+    headers = {
+        "X-Amz-Target": "DynamoDB_20111205.PutItem",
+        "Content-Type": "application/x-amz-json-1.0",
+    }
+    request_body = {
+        "TableName": "Table1",
+        "Item": {
+            "hkey": {"S": "customer"},
+            "rkey": {"N": rkey},
+            "name": {"S": "myname"},
+        },
+        "ReturnValues": "ALL_OLD",
+    }
+    res = test_client.post("/", headers=headers, json=request_body)
+    res = json.loads(res.data)
+    return headers, res
+
+
+def create_table(test_client):
+    headers = {
+        "X-Amz-Target": "DynamoDB_20111205.CreateTable",
+        "Content-Type": "application/x-amz-json-1.0",
+    }
+    request_body = {
+        "TableName": "Table1",
+        "KeySchema": {
+            "HashKeyElement": {"AttributeName": "hkey", "AttributeType": "S"},
+            "RangeKeyElement": {"AttributeName": "rkey", "AttributeType": "N"},
+        },
+        "ProvisionedThroughput": {"ReadCapacityUnits": 5, "WriteCapacityUnits": 10},
+    }
+    return test_client.post("/", headers=headers, json=request_body)