From f6465df63077ad2b738c0dd94baaa3cca1a4f2c9 Mon Sep 17 00:00:00 2001
From: Andrew Garrett <2rs2ts@users.noreply.github.com>
Date: Sat, 4 Mar 2017 20:00:25 -0800
Subject: [PATCH] Return CF Stack events in reverse chronological order (#853)

This is how the AWS API works:
http://boto3.readthedocs.io/en/latest/reference/services/cloudformation.html#CloudFormation.Client.describe_stack_events
---
 moto/cloudformation/responses.py                      |  2 +-
 .../test_cloudformation_stack_crud.py                 | 11 ++++++++---
 .../test_cloudformation_stack_crud_boto3.py           | 11 ++++++++---
 3 files changed, 17 insertions(+), 7 deletions(-)

diff --git a/moto/cloudformation/responses.py b/moto/cloudformation/responses.py
index 06d0bbb00..695118319 100644
--- a/moto/cloudformation/responses.py
+++ b/moto/cloudformation/responses.py
@@ -292,7 +292,7 @@ DESCRIBE_STACK_RESOURCES_RESPONSE = """<DescribeStackResourcesResponse>
 DESCRIBE_STACK_EVENTS_RESPONSE = """<DescribeStackEventsResponse xmlns="http://cloudformation.amazonaws.com/doc/2010-05-15/">
   <DescribeStackEventsResult>
     <StackEvents>
-      {% for event in stack.events %}
+      {% for event in stack.events[::-1] %}
       <member>
         <Timestamp>{{ event.timestamp.strftime('%Y-%m-%dT%H:%M:%S.%fZ') }}</Timestamp>
         <ResourceStatus>{{ event.resource_status }}</ResourceStatus>
diff --git a/tests/test_cloudformation/test_cloudformation_stack_crud.py b/tests/test_cloudformation/test_cloudformation_stack_crud.py
index e145ea283..7eb563c42 100644
--- a/tests/test_cloudformation/test_cloudformation_stack_crud.py
+++ b/tests/test_cloudformation/test_cloudformation_stack_crud.py
@@ -509,10 +509,15 @@ def test_describe_stack_events_shows_create_update_and_delete():
     events[-1].resource_type.should.equal("AWS::CloudFormation::Stack")
 
     # testing ordering of stack events without assuming resource events will not exist
+    # the AWS API returns events in reverse chronological order
     stack_events_to_look_for = iter([
-        ("CREATE_IN_PROGRESS", "User Initiated"), ("CREATE_COMPLETE", None),
-        ("UPDATE_IN_PROGRESS", "User Initiated"), ("UPDATE_COMPLETE", None),
-        ("DELETE_IN_PROGRESS", "User Initiated"), ("DELETE_COMPLETE", None)])
+        ("DELETE_COMPLETE", None),
+        ("DELETE_IN_PROGRESS", "User Initiated"),
+        ("UPDATE_COMPLETE", None),
+        ("UPDATE_IN_PROGRESS", "User Initiated"),
+        ("CREATE_COMPLETE", None),
+        ("CREATE_IN_PROGRESS", "User Initiated"),
+    ])
     try:
         for event in events:
             event.stack_id.should.equal(stack_id)
diff --git a/tests/test_cloudformation/test_cloudformation_stack_crud_boto3.py b/tests/test_cloudformation/test_cloudformation_stack_crud_boto3.py
index 97c3e864a..98ed213e5 100644
--- a/tests/test_cloudformation/test_cloudformation_stack_crud_boto3.py
+++ b/tests/test_cloudformation/test_cloudformation_stack_crud_boto3.py
@@ -345,10 +345,15 @@ def test_stack_events():
     events[-1].resource_type.should.equal("AWS::CloudFormation::Stack")
 
     # testing ordering of stack events without assuming resource events will not exist
+    # the AWS API returns events in reverse chronological order
     stack_events_to_look_for = iter([
-        ("CREATE_IN_PROGRESS", "User Initiated"), ("CREATE_COMPLETE", None),
-        ("UPDATE_IN_PROGRESS", "User Initiated"), ("UPDATE_COMPLETE", None),
-        ("DELETE_IN_PROGRESS", "User Initiated"), ("DELETE_COMPLETE", None)])
+        ("DELETE_COMPLETE", None),
+        ("DELETE_IN_PROGRESS", "User Initiated"),
+        ("UPDATE_COMPLETE", None),
+        ("UPDATE_IN_PROGRESS", "User Initiated"),
+        ("CREATE_COMPLETE", None),
+        ("CREATE_IN_PROGRESS", "User Initiated"),
+    ])
     try:
         for event in events:
             event.stack_id.should.equal(stack.stack_id)