[Resolve #1506] Remove unused __eq__ method (#1508)

Way back in 2018, the original team were adding the debug command, and in that context set about to improve the output in some debug circumstances during inspection of Sceptre's internal objects.

In response to #570, a custom __eq__ method was added in df9fc20.

Based on what can be seen of the original implementation of the custom __eq__, it has not been maintained in a long time, other than changes to it that appeared forced on the current maintainers.

A recent change 993ef09 was done to improve the output during cyclical dependency errors. This change introduced a call to nx.find_cycle, a function that explicitly searches for a cycle in the graph. This appears to result in code testing for the equality of nodes in the graph and thus calls to the custom __eq__ method.

The __eq__ method however has been technically broken ever since template_path was made optional. This then results in __eq__ failing. This fails as the code to announce the deprecation of template_path is then executed, which fails if the deprecated setting is not actually in use.

This PR proposes to simply remove __eq__ since it is believed that it is no longer in use by anything. It has been more than 2 years since template_path was deprecrated and made optional, and the fact that this bug has not surfaced until now is good evidence that the code is not otherwise used or needed.

sceptre/stack.py

@@ -354,30 +354,6 @@ def __repr__(self):
     def __str__(self):
         return self.name
 
-    def __eq__(self, stack):
-        # We should not use any resolvable properties in __eq__, since it is used when adding the
-        # Stack to a set, which is done very early in plan resolution. Trying to reference resolvers
-        # before the plan is fully resolved can potentially blow up.
-        return (
-            self.name == stack.name
-            and self.external_name == stack.external_name
-            and self.project_code == stack.project_code
-            and self.template_path == stack.template_path
-            and self.region == stack.region
-            and self.template_key_prefix == stack.template_key_prefix
-            and self.required_version == stack.required_version
-            and self.sceptre_role_session_duration
-            == stack.sceptre_role_session_duration
-            and self.profile == stack.profile
-            and self.dependencies == stack.dependencies
-            and self.protected == stack.protected
-            and self.on_failure == stack.on_failure
-            and self.disable_rollback == stack.disable_rollback
-            and self.stack_timeout == stack.stack_timeout
-            and self.ignore == stack.ignore
-            and self.obsolete == stack.obsolete
-        )
-
     def __hash__(self):
         return hash(str(self))