[ruby/logger] Add support for changing severity using bang methods.

https://github.com/ruby/logger/commit/ae4c6dfcbb

lib/logger.rb

@@ -322,22 +322,37 @@ class Logger
   # +DEBUG+ messages.
   def debug?; @level <= DEBUG; end
 
+  # Sets the severity to DEBUG.
+  def debug!; self.level = DEBUG; end
+
   # Returns +true+ iff the current severity level allows for the printing of
   # +INFO+ messages.
   def info?; @level <= INFO; end
 
+  # Sets the severity to INFO.
+  def info!; self.level = INFO; end
+
   # Returns +true+ iff the current severity level allows for the printing of
   # +WARN+ messages.
   def warn?; @level <= WARN; end
 
+  # Sets the severity to WARN.
+  def warn!; self.level = WARN; end
+
   # Returns +true+ iff the current severity level allows for the printing of
   # +ERROR+ messages.
   def error?; @level <= ERROR; end
 
+  # Sets the severity to ERROR.
+  def error!; self.level = ERROR; end
+
   # Returns +true+ iff the current severity level allows for the printing of
   # +FATAL+ messages.
   def fatal?; @level <= FATAL; end
 
+  # Sets the severity to FATAL.
+  def fatal!; self.level = FATAL; end
+
   #
   # :call-seq:
   #   Logger.new(logdev, shift_age = 0, shift_size = 1048576)

test/logger/test_severity.rb

@@ -13,4 +13,15 @@ class TestLoggerSeverity < Test::Unit::TestCase
     end
     assert_equal(levels.size, Logger::Severity.constants.size)
   end
+  
+  def test_level_assignment
+    logger = Logger.new(nil)
+    
+    Logger::Severity.constants.each do |level|
+      next if level == :UNKNOWN
+      
+      logger.send("#{level.downcase}!")
+      assert(logger.level) == Logger::Severity.const_get(level)
+    end
+  end
 end