Geocoder.log should always return nil

lib/geocoder/logger.rb

@@ -18,17 +18,19 @@ module Geocoder
     }
 
     def log(level, message)
+      return nil unless valid_level?(level)
+
       logger = Geocoder.config[:logger]
-      return true unless valid_level?(level)
 
       if logger == :kernel
         kernel_log(level, message)
-      elsif logger.respond_to? :add
+      elsif logger.kind_of? ::Logger
         logger.add(SEVERITY[level], message)
       else
         raise Geocoder::ConfigurationError, "Please specify valid logger for Geocoder. " +
         "Logger specified must be :kernel or must respond to `add(level, message)`."
       end
+      nil
     end
 
     private

test/unit/logger_test.rb

@@ -18,13 +18,13 @@ class LoggerTest < GeocoderTestCase
   end
 
   def test_set_logger_logs
-    Geocoder.log(:warn, "should log")
+    assert_equal nil, Geocoder.log(:warn, "should log")
     assert_equal "should log\n", @tempfile.read
   end
 
   def test_set_logger_does_not_log_severity_too_low
     @logger.level = Logger::ERROR
-    assert_equal true, Geocoder.log(:info, "should not log")
+    assert_equal nil, Geocoder.log(:info, "should not log")
     assert_equal "", @tempfile.read
   end
 
@@ -34,4 +34,13 @@ class LoggerTest < GeocoderTestCase
       Geocoder.log(:info, "should raise error")
     end
   end
+
+  def test_set_logger_always_returns_nil
+    assert_equal nil, Geocoder.log(:info, "should log")
+  end
+
+  def test_kernel_logger_always_returns_nil
+    Geocoder.configure(logger: :kernel)
+    assert_equal nil, Geocoder.log(:info, "should log")
+  end
 end