lib/logger.rb: allow specifying log level via Logger.newfeature/logger-constructor-level

* lib/logger.rb (initialize): Allow specifying log severity level in
  constructor. Logger.new(*args, level: lev) becomes effectively same as
  Logger.new(*args).tap { |l| l.level = lev }.
* test/logger/test_logger.rb: Add test for this.

1 files changed, 7 insertions, 0 deletions

diff --git a/test/logger/test_logger.rb b/test/logger/test_logger.rb
index 836d3b30f4..fea7aa0613 100644
--- a/test/logger/test_logger.rb
+++ b/test/logger/test_logger.rb
@@ -292,4 +292,11 @@ class TestLogger < Test::Unit::TestCase
     r.close
     assert_equal("msg2\n\n", msg)
   end
+
+  def test_initialize_specify_level
+    logger = Logger.new(STDERR) # default value
+    assert_equal(Logger::DEBUG, logger.level)
+    logger = Logger.new(STDERR, level: :info)
+    assert_equal(Logger::INFO, logger.level)
+  end
 end