1 files changed, 33 insertions, 0 deletions
diff --git a/activerecord/lib/active_record/dynamic_finder_match.rb b/activerecord/lib/active_record/dynamic_finder_match.rb
new file mode 100644
index 0000000000..4618e777a4
--- /dev/null
+++ b/activerecord/lib/active_record/dynamic_finder_match.rb
@@ -0,0 +1,33 @@
+module ActiveRecord
+  class DynamicFinderMatch
+    def self.match(method)
+      df_match = self.new(method)
+      df_match.finder ? df_match : nil
+    end
+
+    def initialize(method)
+      @finder = :find_initial
+      case method.to_s
+      when /^find_(all_by|by)_([_a-zA-Z]\w*)$/
+        @finder = :find_every if $1 == 'all_by'
+        names = $2
+      when /^find_or_(initialize|create)_by_([_a-zA-Z]\w*)$/
+        @instantiator = $1 == 'initialize' ? :new : :create
+        names = $2
+      else
+        @finder = nil
+      end
+      @attribute_names = names && names.split('_and_')
+    end
+
+    attr_reader :finder, :attribute_names, :instantiator
+
+    def finder?
+      !@finder.nil? && @instantiator.nil?
+    end
+
+    def instantiator?
+      @finder == :find_initial && !@instantiator.nil?
+    end
+  end
+end