Multi Formatter

README.md

@@ -414,18 +414,12 @@ being an instance of SimpleCov::Result. Do whatever your wish with that!
 
 ## Using multiple formatters
 
-There is currently no built-in support for this, but you could help yourself with a wrapper class:
+Configure the formatter to use built-in MultiFormatter:
 
-    class SimpleCov::Formatter::MergedFormatter
-      def format(result)
-         SimpleCov::Formatter::HTMLFormatter.new.format(result)
-         SimpleCov::Formatter::CSVFormatter.new.format(result)
-      end
-    end
-
-Then configure the formatter to use the new merger:
-
-    SimpleCov.formatter = SimpleCov::Formatter::MergedFormatter
+    SimpleCov.formatter = SimpleCov::Formatter::MultiFormatter[
+      SimpleCov::Formatter::HTMLFormatter,
+      SimpleCov::Formatter::CSVFormatter,
+    ]
 
 ## Available formatters
 

features/config_formatters.feature

@@ -0,0 +1,52 @@
+@test_unit @config
+Feature:
+
+  The formatter for test coverage can be customized
+  with the SimpleCov.formatter setting. There are two
+  built-in formatters:
+    SimpleCov::Formatter::SimpleFormatter is a simple
+    formatter returning a string of all files with
+    theirs coverages.
+    SimpleCov::Formatter::MultiFormatter is a formatter
+    used to call multiple formatters at once.
+
+  Scenario: With SimpleFormatter
+    Given SimpleCov for Test/Unit is configured with:
+      """
+      require 'simplecov'
+      SimpleCov.formatter = SimpleCov::Formatter::SimpleFormatter
+      SimpleCov.at_exit do
+        puts SimpleCov.result.format!
+      end
+      SimpleCov.start do
+        add_group 'Libs', 'lib/faked_project/'
+      end
+      """
+
+    When I successfully run `bundle exec rake test`
+    Then the output should contain "lib/faked_project/meta_magic.rb (coverage: 100.0%)"
+
+  Scenario: With MultiFormatter
+    Given SimpleCov for Test/Unit is configured with:
+      """
+      require 'simplecov'
+      SimpleCov.formatter = SimpleCov::Formatter::MultiFormatter[
+        SimpleCov::Formatter::SimpleFormatter,
+        Class.new do
+          def format(result)
+            raise "Unable to format"
+          end
+        end
+      ]
+
+      SimpleCov.at_exit do
+        puts SimpleCov.result.format!.join
+      end
+      SimpleCov.start do
+        add_group 'Libs', 'lib/faked_project/'
+      end
+      """
+
+    When I successfully run `bundle exec rake test`
+    Then the output should contain "lib/faked_project/meta_magic.rb (coverage: 100.0%)"
+    And the output should match /Formatter [^\s]* failed with RuntimeError: Unable to format/

lib/simplecov/formatter.rb

@@ -5,3 +5,4 @@ module Formatter
 end
 
 require 'simplecov/formatter/simple_formatter'
+require 'simplecov/formatter/multi_formatter'

lib/simplecov/formatter/multi_formatter.rb

@@ -0,0 +1,25 @@
+class SimpleCov::Formatter::MultiFormatter
+  def self.[](*args)
+    Class.new(self) do
+      define_method :formatters do
+        @formatters ||= args
+      end
+    end
+  end
+
+  def format(result)
+    formatters.map do |formatter|
+      begin
+        formatter.new.format(result)
+      rescue => e
+        STDERR.puts("Formatter #{formatter} failed with #{e.class}: #{e.message} (#{e.backtrace.first})")
+        nil
+      end
+    end
+  end
+
+  def formatters
+    @formatters ||= []
+  end
+
+end

test/test_result.rb

@@ -111,6 +111,21 @@ class TestResult < Test::Unit::TestCase
             assert_equal String, @result.format!.class
           end
         end
+
+        context "and multi formatter being used" do
+          setup do
+            SimpleCov.formatter = SimpleCov::Formatter::MultiFormatter[
+              SimpleCov::Formatter::SimpleFormatter,
+              SimpleCov::Formatter::SimpleFormatter,
+            ]
+          end
+
+          should "return an array containing formatted string with result.format!" do
+            formated = @result.format!
+            assert_equal 2, formated.count
+            assert_equal String, formated.first.class
+          end
+        end
       end
 
       context "with groups set up that do not match all files" do