Support SNS subscription attributes (#1087)

* remove code for local test

* Add SNS set_subscription_attributes and get_subscription_attributes

tests/test_sns/test_subscriptions_boto3.py

@@ -1,8 +1,12 @@
 from __future__ import unicode_literals
 import boto3
+import json
 
 import sure  # noqa
 
+from botocore.exceptions import ClientError
+from nose.tools import assert_raises
+
 from moto import mock_sns
 from moto.sns.models import DEFAULT_PAGE_SIZE
 
@@ -124,3 +128,72 @@ def test_subscription_paging():
     topic1_subscriptions["Subscriptions"].should.have.length_of(
         int(DEFAULT_PAGE_SIZE / 3))
     topic1_subscriptions.shouldnt.have("NextToken")
+
+
+@mock_sns
+def test_set_subscription_attributes():
+    conn = boto3.client('sns', region_name='us-east-1')
+    conn.create_topic(Name="some-topic")
+    response = conn.list_topics()
+    topic_arn = response["Topics"][0]['TopicArn']
+
+    conn.subscribe(TopicArn=topic_arn,
+                   Protocol="http",
+                   Endpoint="http://example.com/")
+
+    subscriptions = conn.list_subscriptions()["Subscriptions"]
+    subscriptions.should.have.length_of(1)
+    subscription = subscriptions[0]
+    subscription["TopicArn"].should.equal(topic_arn)
+    subscription["Protocol"].should.equal("http")
+    subscription["SubscriptionArn"].should.contain(topic_arn)
+    subscription["Endpoint"].should.equal("http://example.com/")
+
+    subscription_arn = subscription["SubscriptionArn"]
+    attrs = conn.get_subscription_attributes(
+        SubscriptionArn=subscription_arn
+    )
+    attrs.should.have.key('Attributes')
+    conn.set_subscription_attributes(
+        SubscriptionArn=subscription_arn,
+        AttributeName='RawMessageDelivery',
+        AttributeValue='true'
+    )
+    delivery_policy = json.dumps({
+        'healthyRetryPolicy': {
+            "numRetries": 10,
+            "minDelayTarget": 1,
+            "maxDelayTarget":2
+        }
+    })
+    conn.set_subscription_attributes(
+        SubscriptionArn=subscription_arn,
+        AttributeName='DeliveryPolicy',
+        AttributeValue=delivery_policy
+    )
+    attrs = conn.get_subscription_attributes(
+        SubscriptionArn=subscription_arn
+    )
+    attrs['Attributes']['RawMessageDelivery'].should.equal('true')
+    attrs['Attributes']['DeliveryPolicy'].should.equal(delivery_policy)
+
+    # not existing subscription
+    with assert_raises(ClientError):
+        conn.set_subscription_attributes(
+            SubscriptionArn='invalid',
+            AttributeName='RawMessageDelivery',
+            AttributeValue='true'
+        )
+    with assert_raises(ClientError):
+        attrs = conn.get_subscription_attributes(
+            SubscriptionArn='invalid'
+        )
+
+
+    # invalid attr name
+    with assert_raises(ClientError):
+        conn.set_subscription_attributes(
+            SubscriptionArn=subscription_arn,
+            AttributeName='InvalidName',
+            AttributeValue='true'
+        )