Add test and fix failed test

Plugins that override `filter_stream` don't need check,
because they may not call `filter` or `filter_with_time`

test/compat/test_calls_super.rb

@@ -32,12 +32,14 @@ def shutdown; end
   end
   class DummyGoodFilter < Fluent::Filter
     def configure(conf); super; end
+    def filter(tag, time, record); end
     def start; super; end
     def before_shutdown; super; end
     def shutdown; super; end
   end
   class DummyBadFilter < Fluent::Filter
     def configure(conf); super; end
+    def filter(tag, time, record); end
     def start; end
     def before_shutdown; end
     def shutdown; end

test/test_filter.rb

@@ -23,17 +23,57 @@ def emit(klass, msgs, conf = '')
   end
 
   sub_test_case 'configure' do
-    test 'check default' do
-      assert_nothing_raised { create_driver }
+    test 'check to implement `filter` method' do
+      klass = Class.new(Fluent::Filter) do |c|
+        def filter(tag, time, record); end
+      end
+
+      assert_nothing_raised do
+        klass.new
+      end
+    end
+
+    test 'check to implement `filter_with_time` method' do
+      klass = Class.new(Fluent::Filter) do |c|
+        def filter_with_time(tag, time, record); end
+      end
+
+      assert_nothing_raised do
+        klass.new
+      end
+    end
+
+    test 'DO NOT check when implement `filter_stream`' do
+      klass = Class.new(Fluent::Filter) do |c|
+        def filter_stream(tag, es); end
+      end
+
+      assert_nothing_raised do
+        klass.new
+      end
     end
-  end
 
-  sub_test_case 'filter' do
     test 'NotImplementedError' do
-      not_implemented_filter = Class.new(Fluent::Filter)
-      assert_raise(NotImplementedError) { emit(not_implemented_filter, ['foo']) }
+      klass = Class.new(Fluent::Filter)
+
+      assert_raise NotImplementedError do
+        klass.new
+      end
+    end
+
+    test 'duplicated method implementation' do
+      klass = Class.new(Fluent::Filter) do |c|
+        def filter(tag, time, record); end
+        def filter_with_time(tag, time, record); end
+      end
+
+      assert_raise do
+        klass.new
+      end
     end
+  end
 
+  sub_test_case 'filter' do
     test 'null filter' do
       null_filter = Class.new(Fluent::Filter) do |c|
         def filter(tag, time, record)
@@ -61,6 +101,7 @@ def filter(tag, time, record)
         def filter_stream(tag, es)
           MultiEventStream.new
         end
+        def filter(tag, time, record); record; end
       end
       es = emit(null_filter, ['foo'])
       assert_equal(0, es.instance_variable_get(:@record_array).size)
@@ -71,6 +112,7 @@ def filter_stream(tag, es)
         def filter_stream(tag, es)
           es
         end
+        def filter(tag, time, record); record; end
       end
       es = emit(pass_filter, ['foo'])
       assert_equal(1, es.instance_variable_get(:@record_array).size)