Add sns.tag_resource

moto/sns/exceptions.py

@@ -10,6 +10,14 @@ class SNSNotFoundError(RESTError):
             "NotFound", message)
 
 
+class ResourceNotFoundError(RESTError):
+    code = 404
+
+    def __init__(self):
+        super(ResourceNotFoundError, self).__init__(
+            'ResourceNotFound', 'Resource does not exist')
+
+
 class DuplicateSnsEndpointError(RESTError):
     code = 400
 
@@ -42,6 +50,14 @@ class InvalidParameterValue(RESTError):
             "InvalidParameterValue", message)
 
 
+class TagLimitExceededError(RESTError):
+    code = 400
+
+    def __init__(self):
+        super(TagLimitExceededError, self).__init__(
+            'TagLimitExceeded', 'Could not complete request: tag quota of per resource exceeded')
+
+
 class InternalError(RESTError):
     code = 500
 

moto/sns/models.py

@@ -18,7 +18,7 @@ from moto.awslambda import lambda_backends
 
 from .exceptions import (
     SNSNotFoundError, DuplicateSnsEndpointError, SnsEndpointDisabled, SNSInvalidParameter,
-    InvalidParameterValue, InternalError
+    InvalidParameterValue, InternalError, ResourceNotFoundError, TagLimitExceededError
 )
 from .utils import make_arn_for_topic, make_arn_for_subscription
 
@@ -504,8 +504,23 @@ class SNSBackend(BaseBackend):
                 raise SNSInvalidParameter("Invalid parameter: FilterPolicy: Match value must be String, number, true, false, or null")
 
     def list_tags_for_resource(self, resource_arn):
+        if resource_arn not in self.topics:
+            raise ResourceNotFoundError
+
         return self.topics[resource_arn]._tags
 
+    def tag_resource(self, resource_arn, tags):
+        if resource_arn not in self.topics:
+            raise ResourceNotFoundError
+
+        updated_tags = self.topics[resource_arn]._tags.copy()
+        updated_tags.update(tags)
+
+        if len(updated_tags) > 50:
+            raise TagLimitExceededError
+
+        self.topics[resource_arn]._tags = updated_tags
+
 
 sns_backends = {}
 for region in Session().get_available_regions('sns'):

moto/sns/responses.py

@@ -699,15 +699,19 @@ class SNSResponse(BaseResponse):
     def list_tags_for_resource(self):
         arn = self._get_param('ResourceArn')
 
-        if arn not in self.backend.topics:
-            error_response = self._error('ResourceNotFound', 'Resource does not exist')
-            return error_response, dict(status=404)
-
         result = self.backend.list_tags_for_resource(arn)
 
         template = self.response_template(LIST_TAGS_FOR_RESOURCE_TEMPLATE)
         return template.render(tags=result)
 
+    def tag_resource(self):
+        arn = self._get_param('ResourceArn')
+        tags = self._get_tags()
+
+        self.backend.tag_resource(arn, tags)
+
+        return self.response_template(TAG_RESOURCE_TEMPLATE).render()
+
 
 CREATE_TOPIC_TEMPLATE = """<CreateTopicResponse xmlns="http://sns.amazonaws.com/doc/2010-03-31/">
      <CreateTopicResult>
@@ -1105,3 +1109,10 @@ LIST_TAGS_FOR_RESOURCE_TEMPLATE = """<ListTagsForResourceResponse xmlns="http://
     <RequestId>97fa763f-861b-5223-a946-20251f2a42e2</RequestId>
   </ResponseMetadata>
 </ListTagsForResourceResponse>"""
+
+TAG_RESOURCE_TEMPLATE = """<TagResourceResponse xmlns="http://sns.amazonaws.com/doc/2010-03-31/">
+    <TagResourceResult/>
+    <ResponseMetadata>
+        <RequestId>fd4ab1da-692f-50a7-95ad-e7c665877d98</RequestId>
+    </ResponseMetadata>
+</TagResourceResponse>"""