Avoid assignments in conditions

.rubocop.yml

@@ -280,7 +280,7 @@ Lint/AmbiguousRegexpLiteral:
   Enabled: true
 
 Lint/AssignmentInCondition:
-  Enabled: false
+  Enabled: true
 
 Lint/BigDecimalNew:
   Enabled: true

app/controllers/users/sessions_controller.rb

@@ -78,7 +78,9 @@ class Users::SessionsController < Sessions::SessionsController
   end
 
   def try_to_authenticate(klass, remember_me = false)
-    if resource = klass.find_for_database_authentication(email: params[:user][:email])
+    resource = klass.find_for_database_authentication(email: params[:user][:email])
+
+    if resource.present?
       if resource.valid_password?(params[:user][:password])
         resource.remember_me = remember_me
         sign_in resource

app/lib/file_size_validator.rb

@@ -7,7 +7,9 @@ class FileSizeValidator < ActiveModel::EachValidator
   RESERVED_OPTIONS  = [:minimum, :maximum, :within, :is, :tokenizer, :too_short, :too_long]
 
   def initialize(options)
-    if range = (options.delete(:in) || options.delete(:within))
+    range = options.delete(:in) || options.delete(:within)
+
+    if range.present?
       raise ArgumentError, ":in and :within must be a Range" if !range.is_a?(Range)
       options[:minimum], options[:maximum] = range.begin, range.end
       options[:maximum] -= 1 if range.exclude_end?