Use rr instead of flexmock

[cosmo0920]

I try to use rr instead of flexmock in tests.
In most cases, using rr is slightly readable than flexmock.

Current status

• test_filter_stdout
• test_output
• test_in_tail
• use mock instead of stub as much as possible

Question

• Should we completely replace flexmock with rr?
  • test_z_refresh_watchers's test case is hard to replace flexmock with rr. → Done.

[cosmo0920]

This test case does not replace flexmock with rr completely.
For now, work in progress.

[kou]

What is the problem?

[cosmo0920]

What is the problem?

Here is a test failure log:

test_z_refresh_watchers:                                                                        F
=================================================================================================================================================================================================
Failure:
  new("test/plugin/data/2010/01/20100102-030406.log", 0, #<RR::DoubleDefinitions::DoubleDefinition:0x007fd273d4c4c8>, anything, true, 1000, anything, anything, anything)
  Called 0 times.
  Expected 1 times.
test_z_refresh_watchers(TailInputTest)
/Users/hhatake/Github/fluentd/test/plugin/test_in_tail.rb:514:in `block (2 levels) in test_z_refresh_watchers'
     511: 
     512:       stub(Fluent::NewTailInput::TailWatcher) do |watcherclass|
     513:         file_position_entry = stub(Fluent::NewTailInput::FilePositionEntry)
  => 514:         watcherclass.new('test/plugin/data/2010/01/20100102-030406.log', EX_RORATE_WAIT, file_position_entry, anything, true, 1000, anything, anything, anything).once do
     515:           mock('TailWatcher') do |watcher|
     516:             watcher.attach(anything).once
     517:             watcher.__send__(:unwatched=).at_least(0)
/Users/hhatake/Github/fluentd/test/plugin/test_in_tail.rb:512:in `block in test_z_refresh_watchers'
/Users/hhatake/Github/fluentd/test/plugin/test_in_tail.rb:490:in `test_z_refresh_watchers'
=================================================================================================================================================================================================
: (0.022009)

[kou]

Your usage is wrong. Use the following patch:

diff --git a/test/plugin/test_in_tail.rb b/test/plugin/test_in_tail.rb
index d9b6086..80dceca 100644
--- a/test/plugin/test_in_tail.rb
+++ b/test/plugin/test_in_tail.rb
@@ -488,19 +488,33 @@ class TailInputTest < Test::Unit::TestCase
     end

     stub(Time) do |timeclass|
-      timeclass.now.returns(Time.new(2010, 1, 2, 3, 4, 5), Time.new(2010, 1, 2, 3, 4, 6), Time.new(2010, 1, 2, 3, 4, 7))
+      nows = [
+        Time.new(2010, 1, 2, 3, 4, 5),
+        Time.new(2010, 1, 2, 3, 4, 6),
+        Time.new(2010, 1, 2, 3, 4, 7),
+      ]
+      timeclass.now do
+        nows.shift
+      end

       stub(Fluent::NewTailInput::TailWatcher) do |watcherclass|
         EX_PATHS.each do |path|
-          file_position_entry = stub(Fluent::NewTailInput::FilePositionEntry)
-          watcherclass.new(path, EX_RORATE_WAIT, file_position_entry, anything, true, 1000, anything, anything).once do
+          new = watcherclass.new(path,
+                                 EX_RORATE_WAIT,
+                                 is_a(Fluent::TailInput::FilePositionEntry),
+                                 anything,
+                                 true,
+                                 1000,
+                                 anything,
+                                 anything) do
             mock('TailWatcher') do |watcher|
               watcher.attach(anything).once
-              watcher.__send__(:unwatched=).at_least(0)
+              watcher.__send__(:unwatched=, true).at_least(0)
               watcher.line_buffer.at_least(0)
               watcher.close.at_least(0)
             end
           end
+          new.once
         end
         plugin.refresh_watchers
       end
@@ -510,14 +524,21 @@ class TailInputTest < Test::Unit::TestCase
       end

       stub(Fluent::NewTailInput::TailWatcher) do |watcherclass|
-        file_position_entry = stub(Fluent::NewTailInput::FilePositionEntry)
-        watcherclass.new('test/plugin/data/2010/01/20100102-030406.log', EX_RORATE_WAIT, file_position_entry, anything, true, 1000, anything, anything, anything).once do
+        new = watcherclass.new('test/plugin/data/2010/01/20100102-030406.log',
+                               EX_RORATE_WAIT,
+                               is_a(Fluent::TailInput::FilePositionEntry),
+                               anything,
+                               true,
+                               1000,
+                               anything,
+                               anything) do
           mock('TailWatcher') do |watcher|
             watcher.attach(anything).once
-            watcher.__send__(:unwatched=).at_least(0)
+            watcher.__send__(:unwatched=, true).at_least(0)
             watcher.line_buffer.at_least(0)
           end
         end
+        new.once
         plugin.refresh_watchers
       end

1. timeclass.now.returns(now1, now2, now3) doesn't define a stub that returns now1, then now2 and then now3. The stub always returns now1.
2. stub(Fluent::NewTailInput::FilePositionEntry) doesn't mean that any FilePositionEntry instances. Use is_a(Fluent::TailInput::FilePositionEntry).
3. watcherclass.new.once do ... end is wrong. do ... end is a block for once not new.
4. watcher.__send__(:unwatched=).at_least(0) misses an expected argument of #unwatched=.
5. The number of arguments of the second watcherclass.new is wrong. It passes 9 arguments but new is called with 8 arguments.

By the way, you should use mock instead of stub to check expected behavior. stub is used just for stub. It means that stub just provides features for running a test. It doesn't check anything. mock is used for checking behaviors. Search "stub mock difference" on Web search engine for details.

[tagomoris]

Replacing flexmock with rr simply looks not good for me.
Anyway, it's a bit late to reconsider this point, and now we have a problem about rr.
#1115