Add logger.push_tags and .pop_tags to complement logger.tagged

3 files changed, 59 insertions, 14 deletions

diff --git a/activesupport/CHANGELOG.md b/activesupport/CHANGELOG.md
index 05a573076e..e8b7392777 100644
--- a/activesupport/CHANGELOG.md
+++ b/activesupport/CHANGELOG.md
@@ -1,5 +1,19 @@
 ## Rails 4.0.0 (unreleased) ##
 
+*   Add logger.push_tags and .pop_tags to complement logger.tagged:
+
+        class Job
+          def before
+            Rails.logger.push_tags :jobs, self.class.name
+          end
+
+          def after
+            Rails.logger.pop_tags 2
+          end
+        end
+
+    *Jeremy Kemper*
+
 *   Allow delegation to the class using the `:class` keyword, replacing
     `self.class` usage:
 
diff --git a/activesupport/lib/active_support/tagged_logging.rb b/activesupport/lib/active_support/tagged_logging.rb
index 6d1ecabcbd..8af6fa4ba7 100644
--- a/activesupport/lib/active_support/tagged_logging.rb
+++ b/activesupport/lib/active_support/tagged_logging.rb
@@ -20,7 +20,24 @@ module ActiveSupport
         super(severity, timestamp, progname, "#{tags_text}#{msg}")
       end
 
-      def clear!
+      def tagged(*tags)
+        new_tags = push_tags *tags
+        yield self
+      ensure
+        pop_tags new_tags.size
+      end
+
+      def push_tags(*tags)
+        tags.flatten.reject(&:blank?).tap do |new_tags|
+          current_tags.concat new_tags
+        end
+      end
+
+      def pop_tags(size = 1)
+        current_tags.pop size
+      end
+
+      def clear_tags!
         current_tags.clear
       end
 
@@ -29,12 +46,12 @@ module ActiveSupport
       end
 
       private
-      def tags_text
-        tags = current_tags
-        if tags.any?
-          tags.collect { |tag| "[#{tag}] " }.join
+        def tags_text
+          tags = current_tags
+          if tags.any?
+            tags.collect { |tag| "[#{tag}] " }.join
+          end
         end
-      end
     end
 
     def self.new(logger)
@@ -42,17 +59,14 @@ module ActiveSupport
       logger.extend(self)
     end
 
-    def tagged(*new_tags)
-      tags     = formatter.current_tags
-      new_tags = new_tags.flatten.reject(&:blank?)
-      tags.concat new_tags
-      yield self
-    ensure
-      tags.pop(new_tags.size)
+    delegate :push_tags, :pop_tags, :clear_tags!, to: :formatter
+
+    def tagged(*tags)
+      formatter.tagged(*tags) { yield self }
     end
 
     def flush
-      formatter.clear!
+      clear_tags!
       super if defined?(super)
     end
   end
diff --git a/activesupport/test/tagged_logging_test.rb b/activesupport/test/tagged_logging_test.rb
index 43cf1a8e4f..fa045baa28 100644
--- a/activesupport/test/tagged_logging_test.rb
+++ b/activesupport/test/tagged_logging_test.rb
@@ -29,6 +29,23 @@ class TaggedLoggingTest < ActiveSupport::TestCase
     assert_equal "[BCX] [Jason] [New] Funky time\n", @output.string
   end
 
+  test "tagged are flattened" do
+    @logger.tagged("BCX", %w(Jason New)) { @logger.info "Funky time" }
+    assert_equal "[BCX] [Jason] [New] Funky time\n", @output.string
+  end
+
+  test "push and pop tags directly" do
+    assert_equal %w(A B C), @logger.push_tags('A', ['B', '  ', ['C']])
+    @logger.info 'a'
+    assert_equal %w(C), @logger.pop_tags
+    @logger.info 'b'
+    assert_equal %w(B), @logger.pop_tags(1)
+    @logger.info 'c'
+    assert_equal [], @logger.clear_tags!
+    @logger.info 'd'
+    assert_equal "[A] [B] [C] a\n[A] [B] b\n[A] c\nd\n", @output.string
+  end
+
   test "does not strip message content" do
     @logger.info "  Hello"
     assert_equal "  Hello\n", @output.string