1 files changed, 55 insertions, 27 deletions

diff --git a/activerecord/lib/active_record/dynamic_finder_match.rb b/activerecord/lib/active_record/dynamic_finder_match.rb
index b309df9b1b..38dbbef5fc 100644
--- a/activerecord/lib/active_record/dynamic_finder_match.rb
+++ b/activerecord/lib/active_record/dynamic_finder_match.rb
@@ -6,33 +6,23 @@ module ActiveRecord
   #
   class DynamicFinderMatch
     def self.match(method)
-      finder       = :first
-      bang         = false
-      instantiator = nil
-
-      case method.to_s
-      when /^find_(all_|last_)?by_([_a-zA-Z]\w*)$/
-        finder = :last if $1 == 'last_'
-        finder = :all if $1 == 'all_'
-        names = $2
-      when /^find_by_([_a-zA-Z]\w*)\!$/
-        bang = true
-        names = $1
-      when /^find_or_(initialize|create)_by_([_a-zA-Z]\w*)$/
-        instantiator = $1 == 'initialize' ? :new : :create
-        names = $2
-      else
-        return nil
+      method = method.to_s
+      klass = [FindBy, FindByBang, FindOrInitializeCreateBy].find do |_klass|
+        _klass.matches?(method)
       end
+      klass.new(method) if klass
+    end
 
-      new(finder, instantiator, bang, names.split('_and_'))
+    def self.matches?(method)
+      method =~ self::METHOD_PATTERN
     end
 
-    def initialize(finder, instantiator, bang, attribute_names)
-      @finder          = finder
-      @instantiator    = instantiator
-      @bang            = bang
-      @attribute_names = attribute_names
+    def initialize(method)
+      @finder = :first
+      @instantiator = nil
+      match_data = method.match(self.class::METHOD_PATTERN)
+      @attribute_names = match_data[-1].split("_and_")
+      initialize_from_match_data(match_data)
     end
 
     attr_reader :finder, :attribute_names, :instantiator
@@ -41,16 +31,54 @@ module ActiveRecord
       @finder && !@instantiator
     end
 
+    def creator?
+      @finder == :first && @instantiator == :create
+    end
+
     def instantiator?
-      @finder == :first && @instantiator
+      @instantiator
     end
 
-    def creator?
-      @finder == :first && @instantiator == :create
+    def bang?
+      false
+    end
+
+    def valid_arguments?(arguments)
+      arguments.size >= @attribute_names.size
     end
 
+    private
+
+    def initialize_from_match_data(match_data)
+    end
+  end
+
+  class FindBy < DynamicFinderMatch
+    METHOD_PATTERN = /^find_(all_|last_)?by_([_a-zA-Z]\w*)$/
+
+    def initialize_from_match_data(match_data)
+      @finder = :last if match_data[1] == 'last_'
+      @finder = :all if match_data[1] == 'all_'
+    end
+  end
+
+  class FindByBang < DynamicFinderMatch
+    METHOD_PATTERN = /^find_by_([_a-zA-Z]\w*)\!$/
+
     def bang?
-      @bang
+      true
+    end
+  end
+
+  class FindOrInitializeCreateBy < DynamicFinderMatch
+    METHOD_PATTERN = /^find_or_(initialize|create)_by_([_a-zA-Z]\w*)$/
+
+    def initialize_from_match_data(match_data)
+      @instantiator = match_data[1] == 'initialize' ? :new : :create
+    end
+
+    def valid_arguments?(arguments)
+      arguments.size == 1 && arguments.first.is_a?(Hash) || super
     end
   end
 end