fix #2011 (#2012)

add support for Scan method using LSI or GSI

tests/test_dynamodb2/test_dynamodb.py

@@ -1531,6 +1531,7 @@ def test_dynamodb_streams_2():
     }
     assert 'LatestStreamLabel' in resp['TableDescription']
     assert 'LatestStreamArn' in resp['TableDescription']
+
     
 @mock_dynamodb2
 def test_condition_expressions():
@@ -1696,8 +1697,8 @@ def test_query_gsi_with_range_key():
     res = dynamodb.query(TableName='test', IndexName='test_gsi',
                          KeyConditionExpression='gsi_hash_key = :gsi_hash_key AND gsi_range_key = :gsi_range_key',
                          ExpressionAttributeValues={
-                            ':gsi_hash_key': {'S': 'key1'},
-                            ':gsi_range_key': {'S': 'range1'}
+                             ':gsi_hash_key': {'S': 'key1'},
+                             ':gsi_range_key': {'S': 'range1'}
                          })
     res.should.have.key("Count").equal(1)
     res.should.have.key("Items")
@@ -1706,3 +1707,45 @@ def test_query_gsi_with_range_key():
         'gsi_hash_key': {'S': 'key1'},
         'gsi_range_key': {'S': 'range1'},
     })
+
+
+@mock_dynamodb2
+def test_scan_by_non_exists_index():
+    dynamodb = boto3.client('dynamodb', region_name='us-east-1')
+
+    dynamodb.create_table(
+        TableName='test',
+        KeySchema=[{'AttributeName': 'id', 'KeyType': 'HASH'}],
+        AttributeDefinitions=[
+            {'AttributeName': 'id', 'AttributeType': 'S'},
+            {'AttributeName': 'gsi_col', 'AttributeType': 'S'}
+        ],
+        ProvisionedThroughput={'ReadCapacityUnits': 1, 'WriteCapacityUnits': 1},
+        GlobalSecondaryIndexes=[
+            {
+                'IndexName': 'test_gsi',
+                'KeySchema': [
+                    {
+                        'AttributeName': 'gsi_col',
+                        'KeyType': 'HASH'
+                    },
+                ],
+                'Projection': {
+                    'ProjectionType': 'ALL',
+                },
+                'ProvisionedThroughput': {
+                    'ReadCapacityUnits': 1,
+                    'WriteCapacityUnits': 1
+                }
+            },
+        ]
+    )
+
+    with assert_raises(ClientError) as ex:
+        dynamodb.scan(TableName='test', IndexName='non_exists_index')
+
+    ex.exception.response['Error']['Code'].should.equal('ValidationException')
+    ex.exception.response['ResponseMetadata']['HTTPStatusCode'].should.equal(400)
+    ex.exception.response['Error']['Message'].should.equal(
+        'The table does not have the specified index: non_exists_index'
+    )