fix: Add custom rubocop rules for email fetch (#8987)

rubocop/custom_cop_location.rb

@@ -0,0 +1,18 @@
+require 'rubocop'
+
+# enforce rubocop custom rules to only be added in the `rubocop` directory
+class CustomCopLocation < RuboCop::Cop::Base
+  MSG = 'Custom cops should be added in the `rubocop` directory.'.freeze
+
+  def on_send(node)
+    return unless node.source.include?('require \'rubocop\'')
+
+    # convert the full path to relative
+    full_path = processed_source.file_path
+    relative_path = Pathname.new(full_path).relative_path_from(Pathname.new(Dir.pwd)).to_s
+
+    return if relative_path.start_with?('rubocop')
+
+    add_offense(node, message: MSG)
+  end
+end

rubocop/use_from_email.rb

@@ -0,0 +1,16 @@
+require 'rubocop'
+
+# Enforces use of from_email for email attribute lookups
+class UseFromEmail < RuboCop::Cop::Base
+  MSG = 'Use `from_email` for email lookups to ensure case insensitivity.'.freeze
+
+  def_node_matcher :find_by_email?, <<~PATTERN
+    (send _ :find_by (hash (pair (sym :email) _)))
+  PATTERN
+
+  def on_send(node)
+    return unless find_by_email?(node)
+
+    add_offense(node, message: MSG)
+  end
+end