1 files changed, 30 insertions, 0 deletions
diff --git a/app/models/concerns/uniquify.rb b/app/models/concerns/uniquify.rb
new file mode 100644
index 00000000000..a7fe5951b6e
--- /dev/null
+++ b/app/models/concerns/uniquify.rb
@@ -0,0 +1,30 @@
+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.
+  #
+  # If `base` is a function/proc, we expect that calling it with a
+  # candidate counter returns a string to test/return.
+  def string(base)
+    @base = base
+    @counter = nil
+
+    increment_counter! while yield(base_string)
+    base_string
+  end
+
+  private
+
+  def base_string
+    if @base.respond_to?(:call)
+      @base.call(@counter)
+    else
+      "#{@base}#{@counter}"
+    end
+  end
+
+  def increment_counter!
+    @counter ||= 0
+    @counter += 1
+  end
+end