Extract code from `Namespace#clean_path` for ghost user generation.

1. Create a `Uniquify` class, which generalizes the process of generating unique
   strings, by accepting a function that defines what "uniqueness" means in a
   given context.

2. WIP: Make sure tests for `Namespace` pass, add more if necessary.

3. WIP: Add tests for `Uniquify`

1 files changed, 2 insertions, 8 deletions

diff --git a/app/models/namespace.rb b/app/models/namespace.rb
index bd0336c984a..8cc3c1473e2 100644
--- a/app/models/namespace.rb
+++ b/app/models/namespace.rb
@@ -98,14 +98,8 @@ class Namespace < ActiveRecord::Base
       # Work around that by setting their username to "blank", followed by a counter.
       path = "blank" if path.blank?
 
-      counter = 0
-      base = path
-      while Namespace.find_by_path_or_name(path)
-        counter += 1
-        path = "#{base}#{counter}"
-      end
-
-      path
+      uniquify = Uniquify.new
+      uniquify.string(path, -> (s) { Namespace.find_by_path_or_name(s) })
     end
   end