Initial commit

lib/duplicate_remover.rb

@@ -0,0 +1,36 @@
+# Updates an attribute for a given model to ensure it is unique
+class DuplicateRemover
+  ERROR_MESSAGE_WHEN_INVALID = "has already been taken"
+
+  def initialize(record, attribute)
+    @record = record
+    @attribute = attribute
+    @original_attribute_value = record.send(attribute)
+    @current_index = 2
+  end
+
+  def perform!
+    while duplicate?
+      record.send("#{attribute}=", new_name)
+      increment_index
+    end
+
+    record.save!
+  end
+
+  private
+
+  attr_reader :attribute, :current_index, :original_attribute_value, :record
+
+  def duplicate?
+    !record.valid? && record.errors[attribute].include?(ERROR_MESSAGE_WHEN_INVALID)
+  end
+
+  def increment_index
+    @current_index += 1
+  end
+
+  def new_name
+    [original_attribute_value, "(#{current_index})"].join(" ")
+  end
+end