diff --git a/app/controllers/default/units_controller.rb b/app/controllers/default/units_controller.rb
index 8108fd8..1dabae9 100644
--- a/app/controllers/default/units_controller.rb
+++ b/app/controllers/default/units_controller.rb
@@ -12,7 +12,7 @@ class Default::UnitsController < ApplicationController
   end
 
   def index
-    @units = current_user.units.defaults_diff.includes(:base).includes(:subunits).ordered
+    @units = current_user.units.defaults_diff.includes(:base, :subunits).ordered
   end
 
   def import
diff --git a/app/controllers/measurements_controller.rb b/app/controllers/measurements_controller.rb
index 0c3ccd6..22ce980 100644
--- a/app/controllers/measurements_controller.rb
+++ b/app/controllers/measurements_controller.rb
@@ -21,10 +21,10 @@ class MeasurementsController < ApplicationController
     quantities -= @prev_quantities
     @readouts = current_user.readouts.build(quantities.map { |q| {quantity: q} })
 
-    all_quantities = @prev_qantities + quantities
+    all_quantities = @prev_quantities + quantities
     @closest_ancestor = current_user.quantities
       .common_ancestors(all_quantities.map(&:parent_id)).first
-    all_quantites << @closest_ancestor if @closest_ancestor
+    all_quantities << @closest_ancestor if @closest_ancestor
 
     @units = current_user.units.ordered
   end
diff --git a/app/controllers/quantities_controller.rb b/app/controllers/quantities_controller.rb
index 1808672..5c0c5ba 100644
--- a/app/controllers/quantities_controller.rb
+++ b/app/controllers/quantities_controller.rb
@@ -9,7 +9,7 @@ class QuantitiesController < ApplicationController
   end
 
   def index
-    @quantities = current_user.quantities.ordered.includes(:parent).includes(:subquantities)
+    @quantities = current_user.quantities.ordered.includes(:parent, :subquantities)
   end
 
   def new
diff --git a/app/controllers/units_controller.rb b/app/controllers/units_controller.rb
index 9803058..d3c6b30 100644
--- a/app/controllers/units_controller.rb
+++ b/app/controllers/units_controller.rb
@@ -9,7 +9,7 @@ class UnitsController < ApplicationController
   end
 
   def index
-    @units = current_user.units.ordered.includes(:base).includes(:subunits)
+    @units = current_user.units.ordered.includes(:base, :subunits)
   end
 
   def new
diff --git a/app/controllers/users_controller.rb b/app/controllers/users_controller.rb
index 4bf7ac4..2c55b94 100644
--- a/app/controllers/users_controller.rb
+++ b/app/controllers/users_controller.rb
@@ -26,6 +26,7 @@ class UsersController < ApplicationController
     raise ParameterInvalid unless allow_disguise?(@user)
     session[:revert_to_id] = current_user.id
     bypass_sign_in(@user)
+    # TODO: add flash with disguised username?
     redirect_to root_url
   end
 
diff --git a/app/helpers/application_helper.rb b/app/helpers/application_helper.rb
index 4d06158..004d24c 100644
--- a/app/helpers/application_helper.rb
+++ b/app/helpers/application_helper.rb
@@ -22,7 +22,7 @@ module ApplicationHelper
     def form_for(&block)
       @template.content_tag(:table, class: "centered") { yield(self) } +
       # Display leftover error messages (there shouldn't be any)
-      @template.content_tag(:div, @object&.errors.full_messages.join(@template.tag :br))
+      @template.content_tag(:div, @object&.errors.full_messages.join(@template.tag(:br)))
     end
 
     private
@@ -38,20 +38,21 @@ module ApplicationHelper
     end
 
     def label_for(method, options = {})
-      return "" if (options[:label] == false)
+      return '' if options[:label] == false
+
       text = options.delete(:label)
       text ||= @object.class.human_attribute_name(method).capitalize
-
       classes = @template.class_names(required: options[:required],
                                       error: @object&.errors[method].present?)
+      label = label(method, "#{text}:", class: classes)
+      hint = options.delete(:hint)
 
-      label(method, text+":", class: classes) +
-        (@template.tag(:br) + @template.content_tag(:em, options.delete(:hint)) if options[:hint])
+      label + (@template.tag(:br) + @template.content_tag(:em, hint) if hint)
     end
   end
 
   def labelled_form_for(record, options = {}, &block)
-    options = options.deep_merge builder: LabelledFormBuilder, data: {turbo: false}
+    options = options.deep_merge(builder: LabelledFormBuilder, data: {turbo: false})
     form_for(record, **options) { |f| f.form_for(&block) }
   end
 
@@ -75,12 +76,14 @@ module ApplicationHelper
 
     def number_field(method, options = {})
       value = object.public_send(method)
-      if value.is_a? BigDecimal
+      if value.is_a?(BigDecimal)
         options[:value] = value.to_scientific
         type = object.class.type_for_attribute(method)
         options[:step] ||= BigDecimal(10).power(-type.scale)
-        options[:max] ||= BigDecimal(10).power(type.precision - type.scale) - options[:step]
-        options[:min] = options[:min] == :step ? options[:step] : options[:min] || -options[:max]
+        options[:max] ||= BigDecimal(10).power(type.precision - type.scale) -
+          options[:step]
+        options[:min] = options[:min] == :step ? options[:step] : options[:min]
+        options[:min] ||= -options[:max]
       end
       super
     end
@@ -107,20 +110,21 @@ module ApplicationHelper
     # skip_default_ids causes turbo to generate unique ID for element with
     # [autofocus].  Otherwise IDs are not unique when multiple forms are open
     # and the first input gets focus.
-    record_object, options = nil, record_object if record_object.is_a? Hash
-    options.merge! builder: TabularFormBuilder, skip_default_ids: true
+    record_object, options = nil, record_object if record_object.is_a?(Hash)
+    options.merge!(builder: TabularFormBuilder, skip_default_ids: true)
     render_errors(record_object || record_name)
     fields_for(record_name, record_object, **options, &block)
   end
 
   def tabular_form_with(**options, &block)
-    options = options.deep_merge builder: TabularFormBuilder, html: {autocomplete: 'off'}
+    options = options.deep_merge(builder: TabularFormBuilder,
+                                 html: {autocomplete: 'off'})
     form_with(**options, &block)
   end
 
   def svg_tag(source, options = {})
     content_tag :svg, options do
-      tag.use href: image_path(source + ".svg") + "#icon"
+      tag.use(href: "#{image_path(source + ".svg")}#icon")
     end
   end