delete tags when their resource is deleted

moto/events/models.py

@@ -143,6 +143,8 @@ class EventsBackend(BaseBackend):
 
     def delete_rule(self, name):
         self.rules_order.pop(self.rules_order.index(name))
+        arn = self.rules.get(name).arn
+        self.tagger.delete_all_tags_for_resource(arn)
         return self.rules.pop(name) is not None
 
     def describe_rule(self, name):

moto/utilities/tagging_service.py

@@ -12,6 +12,9 @@ class TaggingService:
                 result.append({self.keyName: k, self.valueName: v})
         return {self.tagName: result}
 
+    def delete_all_tags_for_resource(self, arn):
+        del self.tags[arn]
+
     def tag_resource(self, arn, tags):
         if arn not in self.tags:
             self.tags[arn] = {}

tests/test_utilities/test_tagging_service.py

@@ -19,6 +19,7 @@ def test_create_tag():
 
     expected.should.be.equal(actual)
 
+
 def test_create_tag_without_value():
     svc = TaggingService()
     tags = [{"Key": "key_key"}]
@@ -28,6 +29,7 @@ def test_create_tag_without_value():
 
     expected.should.be.equal(actual)
 
+
 def test_delete_tag_using_names():
     svc = TaggingService()
     tags = [{"Key": "key_key", "Value": "value_value"}]
@@ -37,6 +39,19 @@ def test_delete_tag_using_names():
 
     {"Tags": []}.should.be.equal(result)
 
+
+def test_delete_all_tags_for_resource():
+    svc = TaggingService()
+    tags = [{"Key": "key_key", "Value": "value_value"}]
+    tags2 = [{"Key": "key_key2", "Value": "value_value2"}]
+    svc.tag_resource("arn", tags)
+    svc.tag_resource("arn", tags2)
+    svc.delete_all_tags_for_resource("arn")
+    result = svc.list_tags_for_resource("arn")
+
+    {"Tags": []}.should.be.equal(result)
+
+
 def test_list_empty_delete():
     svc = TaggingService()
     svc.untag_resource_using_names("arn", ["key_key"])
@@ -44,6 +59,7 @@ def test_list_empty_delete():
 
     {"Tags": []}.should.be.equal(result)
 
+
 def test_delete_tag_using_tags():
     svc = TaggingService()
     tags = [{"Key": "key_key", "Value": "value_value"}]
@@ -61,4 +77,3 @@ def test_extract_tag_names():
     expected = ["key1", "key2"]
 
     expected.should.be.equal(actual)
-