Use $stdout instead of STDOUT for the default logdev.

This makes it testable using minitest/rspec IO
assertions/expectations. STDOUT/STDERR should only be used to restore
$stdout/$stderr if something goes haywire. The globals should be used
for everyday use.

Also bolstered an IO test to prevent the output from going to the
rspec result output.

Signed-off-by: Ryan Davis <zenspider@chef.io>

3 files changed, 12 insertions, 5 deletions

diff --git a/lib/mixlib/log.rb b/lib/mixlib/log.rb
index 18cdfd3..599ac57 100644
--- a/lib/mixlib/log.rb
+++ b/lib/mixlib/log.rb
@@ -170,7 +170,7 @@ module Mixlib
 
     def logger_for(*opts)
       if opts.empty?
-        Mixlib::Log::Logger.new(STDOUT)
+        Mixlib::Log::Logger.new($stdout)
       elsif LEVELS.keys.inject(true) { |quacks, level| quacks && opts.first.respond_to?(level) }
         opts.first
       else
diff --git a/lib/mixlib/log/logger.rb b/lib/mixlib/log/logger.rb
index f92d4a2..f227f23 100644
--- a/lib/mixlib/log/logger.rb
+++ b/lib/mixlib/log/logger.rb
@@ -21,7 +21,7 @@ module Mixlib
       #
       # +logdev+::
       #   The log device.  This is a filename (String) or IO object (typically
-      #   +STDOUT+, +STDERR+, or an open file).
+      #   +$stdout+, +$stderr+, or an open file).
       # +shift_age+::
       #   Number of old log files to keep, *or* frequency of rotation (+daily+,
       #   +weekly+ or +monthly+).
diff --git a/spec/mixlib/log_spec.rb b/spec/mixlib/log_spec.rb
index bbf290b..b58c4e2 100644
--- a/spec/mixlib/log_spec.rb
+++ b/spec/mixlib/log_spec.rb
@@ -142,9 +142,14 @@ RSpec.describe Mixlib::Log do
   end
 
   it "should pass other method calls directly to logger" do
-    Logit.level = :debug
-    expect(Logit).to be_debug
-    expect { Logit.debug("Gimme some sugar!") }.to_not raise_error
+    expect do
+      # this needs to be inside of the block because the level setting
+      # is causing the init, which grabs $stderr before rspec replaces
+      # it for output testing.
+      Logit.level = :debug
+      expect(Logit).to be_debug
+      Logit.debug("Gimme some sugar!")
+    end.to output(/DEBUG: Gimme some sugar!/).to_stdout
   end
 
   it "should pass add method calls directly to logger" do
@@ -158,6 +163,7 @@ RSpec.describe Mixlib::Log do
 
   it "should default to STDOUT if init is called with no arguments" do
     logger_mock = Struct.new(:formatter, :level).new
+    # intentionally STDOUT to avoid unfailable test
     expect(Logger).to receive(:new).with(STDOUT).and_return(logger_mock)
     Logit.init
   end
@@ -203,6 +209,7 @@ RSpec.describe Mixlib::Log do
   end
 
   it "should return nil from its logging methods" do
+    # intentionally STDOUT to avoid unfailable test
     expect(Logger).to receive(:new).with(STDOUT) { double("a-quiet-logger").as_null_object }
     Logit.init