test driver: Return the return value of yield

Fix fluent#1268

lib/fluent/test/driver/base.rb

@@ -140,7 +140,7 @@ def run_actual(timeout: nil, &block)
           end
 
           proc = if block_given?
-                   ->(){ block.call; sleep(0.1) until stop? }
+                   ->(){ value = block.call; sleep(0.1) until stop?; value }
                  else
                    ->(){ sleep(0.1) until stop? }
                  end

lib/fluent/test/driver/output.rb

@@ -41,11 +41,12 @@ def run(flush: true, **kwargs, &block)
         end
 
         def run_actual(**kwargs, &block)
-          super(**kwargs, &block)
+          value = super(**kwargs, &block)
           if @flush_buffer_at_cleanup
             @instance.force_flush
             Timeout.timeout(10){ sleep 0.1 until !@instance.buffer || @instance.buffer.queue.size == 0 }
           end
+          value
         end
 
         def formatted

test/driver/test_filter.rb

@@ -0,0 +1,30 @@
+require_relative '../helper'
+require 'fluent/test/driver/filter'
+
+class NullFilter < Fluent::Plugin::Filter
+  def filter(tag, time, record)
+  end
+end
+
+class TestDriverFilterTest < Test::Unit::TestCase
+  def setup
+    Fluent::Test.setup
+  end
+
+  def create_driver(conf = "")
+    Fluent::Test::Driver::Filter.new(NullFilter).configure(conf)
+  end
+
+  test 'run w/ block returns last evaluated value in block' do
+    d = create_driver
+    value = d.run do
+      :value
+    end
+    assert_equal(value, :value)
+  end
+
+  test 'run w/o block returns nil' do
+    d = create_driver
+    assert_nil(d.run(timeout: 0.01))
+  end
+end

test/driver/test_formatter.rb

@@ -0,0 +1,30 @@
+require_relative '../helper'
+require 'fluent/test/driver/formatter'
+
+class NullFormatter < Fluent::Plugin::Formatter
+  def format(tag, time, record)
+  end
+end
+
+class TestDriverFormatterTest < Test::Unit::TestCase
+  def setup
+    Fluent::Test.setup
+  end
+
+  def create_driver(conf = "")
+    Fluent::Test::Driver::Formatter.new(NullFormatter).configure(conf)
+  end
+
+  test 'run w/ block returns last evaluated value in block' do
+    d = create_driver
+    value = d.run do
+      :value
+    end
+    assert_equal(value, :value)
+  end
+
+  test 'run w/o block returns nil' do
+    d = create_driver
+    assert_nil(d.run(timeout: 0.01))
+  end
+end

test/driver/test_input.rb

@@ -0,0 +1,28 @@
+require_relative '../helper'
+require 'fluent/test/driver/input'
+
+class NullInput < Fluent::Plugin::Input
+end
+
+class TestDriverInputTest < Test::Unit::TestCase
+  def setup
+    Fluent::Test.setup
+  end
+
+  def create_driver(conf = "")
+    Fluent::Test::Driver::Input.new(NullInput).configure(conf)
+  end
+
+  test 'run w/ block returns last evaluated value in block' do
+    d = create_driver
+    value = d.run do
+      :value
+    end
+    assert_equal(value, :value)
+  end
+
+  test 'run w/o block returns nil' do
+    d = create_driver
+    assert_nil(d.run(timeout: 0.01))
+  end
+end

test/driver/test_output.rb

@@ -0,0 +1,26 @@
+require_relative '../helper'
+require 'fluent/test/driver/output'
+require 'fluent/plugin/out_null'
+
+class TestDriverOutputTest < Test::Unit::TestCase
+  def setup
+    Fluent::Test.setup
+  end
+
+  def create_driver(conf = "")
+    Fluent::Test::Driver::Output.new(Fluent::Plugin::NullOutput).configure(conf)
+  end
+
+  test 'run w/ block returns last evaluated value in block' do
+    d = create_driver
+    value = d.run do
+      :value
+    end
+    assert_equal(value, :value)
+  end
+
+  test 'run w/o block returns nil' do
+    d = create_driver
+    assert_nil(d.run(timeout: 0.01))
+  end
+end

test/driver/test_parser.rb

@@ -0,0 +1,31 @@
+require_relative '../helper'
+require 'fluent/test/driver/parser'
+
+class NullParser < Fluent::Plugin::Parser
+  def parse(text)
+    yield nil, nil
+  end
+end
+
+class TestDriverParserTest < Test::Unit::TestCase
+  def setup
+    Fluent::Test.setup
+  end
+
+  def create_driver(conf = "")
+    Fluent::Test::Driver::Parser.new(NullParser).configure(conf)
+  end
+
+  test 'run w/ block returns last evaluated value in block' do
+    d = create_driver
+    value = d.run do
+      :value
+    end
+    assert_equal(value, :value)
+  end
+
+  test 'run w/o block returns nil' do
+    d = create_driver
+    assert_nil(d.run(timeout: 0.01))
+  end
+end