1 files changed, 7 insertions, 14 deletions
diff --git a/lib/minitest/mock.rb b/lib/minitest/mock.rb
index 99f7992aa9..4871e8b183 100644
--- a/lib/minitest/mock.rb
+++ b/lib/minitest/mock.rb
@@ -14,7 +14,14 @@ module MiniTest
     end
 
     def expect(name, retval, args=[])
+      n, r = name, retval # for the closure below
       @expected_calls[name] = { :retval => retval, :args => args }
+      self.class.__send__ :remove_method, name if respond_to? name
+      self.class.__send__(:define_method, name) { |*x|
+        raise ArgumentError unless @expected_calls[n][:args].size == x.size
+        @actual_calls[n] << { :retval => r, :args => x }
+        retval
+      }
       self
     end
 
@@ -27,19 +34,5 @@ module MiniTest
       end
       true
     end
-
-    def method_missing(sym, *args)
-      raise NoMethodError unless @expected_calls.has_key?(sym)
-      raise ArgumentError unless @expected_calls[sym][:args].size == args.size
-      retval = @expected_calls[sym][:retval]
-      @actual_calls[sym] << { :retval => retval, :args => args }
-      retval
-    end
-
-    alias :original_respond_to? :respond_to?
-    def respond_to?(sym)
-      return true if @expected_calls.has_key?(sym)
-      return original_respond_to?(sym)
-    end
   end
 end