resolves #3982 allow NullLogger to be enabled by setting the :logger option to a falsy value (PR #3983)

3 files changed, 15 insertions, 2 deletions

diff --git a/CHANGELOG.adoc b/CHANGELOG.adoc
index 6dfcf37c..00512cc8 100644
--- a/CHANGELOG.adoc
+++ b/CHANGELOG.adoc
@@ -23,6 +23,7 @@ Improvements::
 
   * Extract method to create lexer and formatter in Rouge adapter (#3952)
   * Add support for pygments.rb 2.x (#3969) (*@slonopotamus*)
+  * Allow NullLogger to be enabled by setting the `:logger` option to a falsy value (#3982)
 
 Build / Infrastructure::
 
diff --git a/lib/asciidoctor/load.rb b/lib/asciidoctor/load.rb
index 46d27c70..febe2f15 100644
--- a/lib/asciidoctor/load.rb
+++ b/lib/asciidoctor/load.rb
@@ -20,8 +20,8 @@ module Asciidoctor
         timings.start :read
       end
 
-      if (logger = options[:logger]) && logger != LoggerManager.logger
-        LoggerManager.logger = logger
+      if (options.key? :logger) && (logger = options[:logger]) != LoggerManager.logger
+        LoggerManager.logger = logger || NullLogger.new
       end
 
       if !(attrs = options[:attributes])
diff --git a/test/logger_test.rb b/test/logger_test.rb
index 77a0792e..87d18c75 100644
--- a/test/logger_test.rb
+++ b/test/logger_test.rb
@@ -129,6 +129,18 @@ context 'Logger' do
         Asciidoctor::LoggerManager.logger = old_logger
       end
     end
+
+    test 'should be able to set logger to NullLogger by setting :logger option to a falsy value' do
+      [nil, false].each do |falsy_val|
+        old_logger = Asciidoctor::LoggerManager.logger
+        begin
+          Asciidoctor.load 'contents', logger: falsy_val
+          assert_kind_of Asciidoctor::NullLogger, Asciidoctor::LoggerManager.logger
+        ensure
+          Asciidoctor::LoggerManager.logger = old_logger
+        end
+      end
+    end
   end
 
   context 'Logging' do