Allow BroadcastLogger to pass through kwargs

When BroadcastLogger is applied to a logger implementation that takes
kwargs, a developer invoking a logging message while passing kwargs will
run into

    ArgumentError: wrong number of arguments (given 2, expected 0..1)

This error is confusing since the 'correct' arguments are passed, and
BroadcastLogger's splat unexpectedly converts the kwargs into a hash
and passes that hash along as a second argument instead of forwarding
along the method arguments unchanged.

Author: soulcutter

activesupport/lib/active_support/broadcast_logger.rb

@@ -113,33 +113,33 @@ def <<(message)
       dispatch { |logger| logger.<<(message) }
     end
 
-    def add(*args, &block)
-      dispatch { |logger| logger.add(*args, &block) }
+    def add(...)
+      dispatch { |logger| logger.add(...) }
     end
     alias_method :log, :add
 
-    def debug(*args, &block)
-      dispatch { |logger| logger.debug(*args, &block) }
+    def debug(...)
+      dispatch { |logger| logger.debug(...) }
     end
 
-    def info(*args, &block)
-      dispatch { |logger| logger.info(*args, &block) }
+    def info(...)
+      dispatch { |logger| logger.info(...) }
     end
 
-    def warn(*args, &block)
-      dispatch { |logger| logger.warn(*args, &block) }
+    def warn(...)
+      dispatch { |logger| logger.warn(...) }
     end
 
-    def error(*args, &block)
-      dispatch { |logger| logger.error(*args, &block) }
+    def error(...)
+      dispatch { |logger| logger.error(...) }
     end
 
-    def fatal(*args, &block)
-      dispatch { |logger| logger.fatal(*args, &block) }
+    def fatal(...)
+      dispatch { |logger| logger.fatal(...) }
     end
 
-    def unknown(*args, &block)
-      dispatch { |logger| logger.unknown(*args, &block) }
+    def unknown(...)
+      dispatch { |logger| logger.unknown(...) }
     end
 
     def formatter=(formatter)

activesupport/test/broadcast_logger_test.rb

@@ -307,6 +307,25 @@ def info(msg, &block)
       assert_equal true, @logger.error("Hello")
     end
 
+    Logger::Severity.constants.each do |level_name|
+      method = level_name.downcase
+      level = Logger::Severity.const_get(level_name)
+
+      test "##{method} delegates keyword arguments to loggers" do
+        logger = BroadcastLogger.new(KwargsAcceptingLogger.new)
+
+        logger.public_send(method, "Hello", foo: "bar")
+        assert_equal [[level, "{:foo=>\"bar\"} Hello", nil]], logger.broadcasts.sole.adds
+      end
+    end
+
+    test "#add delegates keyword arguments to the loggers" do
+      logger = BroadcastLogger.new(KwargsAcceptingLogger.new)
+
+      logger.add(::Logger::INFO, "Hello", foo: "bar")
+      assert_equal [[::Logger::INFO, "{:foo=>\"bar\"} Hello", nil]], logger.broadcasts.sole.adds
+    end
+
     class CustomLogger
       attr_reader :adds, :closed, :chevrons
       attr_accessor :level, :progname, :formatter, :local_level
@@ -401,5 +420,19 @@ class FakeLogger < CustomLogger
       # methods, so we need to redefine them
       attr_accessor :level, :local_level
     end
+
+    class KwargsAcceptingLogger < CustomLogger
+      Logger::Severity.constants.each do |level_name|
+        method = level_name.downcase
+        define_method(method) do |message, **kwargs|
+          add(Logger::Severity.const_get(level_name), "#{kwargs.inspect} #{message}")
+        end
+      end
+
+      def add(severity, message = nil, **kwargs)
+        return super(severity, "#{kwargs.inspect} #{message}") if kwargs.present?
+        super
+      end
+    end
   end
 end