style(rubocop): fix all safe auto correctable offenses

app/models/additional_route_endpoint.rb

@@ -13,22 +13,21 @@
 class AdditionalRouteEndpoint < ApplicationRecord
 
   belongs_to :route
-  belongs_to :endpoint, :polymorphic => true
+  belongs_to :endpoint, polymorphic: true
 
   validate :validate_endpoint_belongs_to_server
   validate :validate_wildcard
   validate :validate_uniqueness
 
   def self.find_by_endpoint(endpoint)
-    class_name, id = endpoint.split('#', 2)
+    class_name, id = endpoint.split("#", 2)
     unless Route::ENDPOINT_TYPES.include?(class_name)
       raise Postal::Error, "Invalid endpoint class name '#{class_name}'"
     end
-    if uuid = class_name.constantize.find_by_uuid(id)
-      where(:endpoint_type => class_name, :endpoint_id => uuid).first
-    else
-      nil
-    end
+
+    return unless uuid = class_name.constantize.find_by_uuid(id)
+
+    where(endpoint_type: class_name, endpoint_id: uuid).first
   end
 
   def _endpoint
@@ -38,39 +37,37 @@ class AdditionalRouteEndpoint < ApplicationRecord
   def _endpoint=(value)
     if value.blank?
       self.endpoint = nil
-    else
-      if value =~ /\#/
-        class_name, id = value.split('#', 2)
-        unless Route::ENDPOINT_TYPES.include?(class_name)
-          raise Postal::Error, "Invalid endpoint class name '#{class_name}'"
-        end
-        self.endpoint = class_name.constantize.find_by_uuid(id)
-      else
-        self.endpoint = nil
+    elsif value =~ /\#/
+      class_name, id = value.split("#", 2)
+      unless Route::ENDPOINT_TYPES.include?(class_name)
+        raise Postal::Error, "Invalid endpoint class name '#{class_name}'"
       end
+
+      self.endpoint = class_name.constantize.find_by_uuid(id)
+    else
+      self.endpoint = nil
     end
   end
 
   private
 
   def validate_endpoint_belongs_to_server
-    if self.endpoint && self.endpoint&.server != self.route.server
-      errors.add :endpoint, :invalid
-    end
+    return unless endpoint && endpoint&.server != route.server
+
+    errors.add :endpoint, :invalid
   end
 
   def validate_uniqueness
-    if self.endpoint == self.route.endpoint
-      errors.add :base, "You can only add an endpoint to a route once"
-    end
+    return unless endpoint == route.endpoint
+
+    errors.add :base, "You can only add an endpoint to a route once"
   end
 
   def validate_wildcard
-    if self.route.wildcard?
-      if self.endpoint_type == 'SMTPEndpoint' || self.endpoint_type == 'AddressEndpoint'
-        errors.add :base, "SMTP or address endpoints are not permitted on wildcard routes"
-      end
-    end
+    return unless route.wildcard?
+    return unless endpoint_type == "SMTPEndpoint" || endpoint_type == "AddressEndpoint"
+
+    errors.add :base, "SMTP or address endpoints are not permitted on wildcard routes"
   end
 
 end