out_copy: test: Assert ignore_if_prev_success function calling

Signed-off-by: Hiroshi Hatake <hatake@clear-code.com>

test/plugin/test_out_copy.rb

@@ -2,8 +2,11 @@
 require 'fluent/test/driver/multi_output'
 require 'fluent/plugin/out_copy'
 require 'fluent/event'
+require 'flexmock/test_unit'
 
 class CopyOutputTest < Test::Unit::TestCase
+  include FlexMock::TestCase
+
   class << self
     def startup
       $LOAD_PATH.unshift File.expand_path(File.join(File.dirname(__FILE__), '..', 'scripts'))
@@ -241,6 +244,16 @@ def test_ignore_if_prev_success
       raise ArgumentError, 'Failed'
     end
 
+    # check ingore_if_prev_success functionality:
+    # 1. output 2 is succeeded.
+    # 2. output 3 is not cailed.
+    flexstub(d.instance.outputs[1]) do |output|
+      output.should_receive(:process).once
+    end
+    flexstub(d.instance.outputs[2]) do |output|
+      output.should_receive(:process).never
+    end
+
     time = Time.parse("2011-01-02 13:14:15 UTC").to_i
     assert_nothing_raised do
       d.run(default_tag: 'test') do