Uses Uniquify to calculate Issue#suggested_branch_name

app/models/concerns/uniquify.rb

@@ -3,11 +3,14 @@ class Uniquify
   # 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)
+  def string(base, counter = nil)
     @base = base
-    @counter = nil
+    @counter = counter
 
     increment_counter! while yield(base_string)
     base_string

app/models/issue.rb

@@ -197,10 +197,10 @@ class Issue < ActiveRecord::Base
   def suggested_branch_name
     return to_branch_name unless project.repository.branch_exists?(to_branch_name)
 
-    index = 2
-    index += 1 while project.repository.branch_exists?("#{to_branch_name}-#{index}")
-
-    "#{to_branch_name}-#{index}"
+    start_counting_from = 2
+    Uniquify.new.string(-> (counter) { "#{to_branch_name}-#{counter}" }, start_counting_from) do |suggested_branch_name|
+      project.repository.branch_exists?(suggested_branch_name)
+    end
   end
 
   # Returns boolean if a related branch exists for the current issue

spec/models/concerns/uniquify_spec.rb

@@ -22,6 +22,13 @@ describe Uniquify do
       expect(result).to eq('test_string2')
     end
 
+    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' }
+
+      expect(result).to eq('test_string2')
+    end
+
     it 'allows passing in a base function that defines the location of the counter' do
       result = uniquify.string(-> (counter) { "test_#{counter}_string" }) do |s|
         s == 'test__string'