Moves Uniquify counter in the initializer

app/models/concerns/uniquify.rb

+# Uniquify
+#
+# Return a version of the given 'base' string that is unique
+# by appending a counter to it. Uniqueness is determined by
+# repeated calls to the passed block.
+#
+# You can pass an initial value for the counter, if not given
+# counting starts from 1.
+#
+# If `base` is a function/proc, we expect that calling it with a
+# candidate counter returns a string to test/return.
 class Uniquify
-  # Return a version of the given 'base' string that is unique
-  # by appending a counter to it. Uniqueness is determined by
-  # repeated calls to the passed block.
-  #
-  # You can pass an initial value for the counter, if not given
-  # counting starts from 1.
-  #
-  # If `base` is a function/proc, we expect that calling it with a
-  # candidate counter returns a string to test/return.
-  def string(base, counter = nil)
-    @base = base
+  def initialize(counter = nil)
     @counter = counter
+  end
+
+  def string(base)
+    @base = base
 
     increment_counter! while yield(base_string)
     base_string

app/models/issue.rb

@@ -198,7 +198,7 @@ class Issue < ActiveRecord::Base
     return to_branch_name unless project.repository.branch_exists?(to_branch_name)
 
     start_counting_from = 2
-    Uniquify.new.string(-> (counter) { "#{to_branch_name}-#{counter}" }, start_counting_from) do |suggested_branch_name|
+    Uniquify.new(start_counting_from).string(-> (counter) { "#{to_branch_name}-#{counter}" }) do |suggested_branch_name|
       project.repository.branch_exists?(suggested_branch_name)
     end
   end

spec/models/concerns/uniquify_spec.rb

@@ -24,7 +24,9 @@ describe Uniquify do
 
     it 'allows to pass an initial value for the counter' do
       start_counting_from = 2
-      result = uniquify.string('test_string', start_counting_from) { |s| s == 'test_string' }
+      uniquify = described_class.new(start_counting_from)
+
+      result = uniquify.string('test_string') { |s| s == 'test_string' }
 
       expect(result).to eq('test_string2')
     end