fix actionmailer concern type errors with RBI

Author: ndbroadbent

lib/rails_structured_logging/action_mailer/error_handling.rb

@@ -15,10 +15,6 @@ module ErrorHandling
       extend ActiveSupport::Concern
 
       included do
-        # Tell Sorbet that 'self' in this context has rescue_from available
-        # This is because the including class will have ActiveSupport::Rescuable mixed in
-        T.cast(self, T.all(Module, T.class_of(ActiveSupport::Rescuable)))
-
         # NOTE: rescue_from handlers are checked in reverse order.
         # The handler that was defined last is checked first, so put
         # more specific handlers at the end.

sorbet/config

@@ -2,3 +2,4 @@
 .
 --ignore=tmp/
 --ignore=vendor/
+--enable-experimental-requires-ancestor

sorbet/rbi/overrides/rails_structured_logging/action_mailer/error_handling.rbi

@@ -0,0 +1,10 @@
+# typed: true
+
+module RailsStructuredLogging::ActionMailer::ErrorHandling
+  extend T::Helpers
+
+  # Tell Sorbet that we are including this module into ActionMailer::Base
+  # and we have the rescue_from class methods available
+  requires_ancestor { ::ActionMailer::Base }
+  extend ::ActiveSupport::Rescuable::ClassMethods
+end