Add a Rake task to push merged reports to Coveralls

Rakefile

@@ -28,6 +28,18 @@ end
 
 task :env do
   ENV["ADAPTER"] = nil
+  ENV["COVERAGE"] = "true"
+end
+
+task :coveralls do
+  require "simplecov"
+  require "coveralls"
+
+  Coveralls::SimpleCov::Formatter.new.format(SimpleCov.result)
+end
+
+Rake::Task[:spec].enhance do
+  Rake::Task[:coveralls].invoke
 end
 
 task default: :spec

spec/spec_helper.rb

@@ -1,17 +1,11 @@
-require "simplecov"
-require "coveralls"
-
-SimpleCov.formatter = SimpleCov::Formatter::MultiFormatter[
-  SimpleCov::Formatter::HTMLFormatter,
-  Coveralls::SimpleCov::Formatter
-]
-
 adapter, gemfile = ENV["ADAPTER"], ENV["BUNDLE_GEMFILE"]
 adapter ||= gemfile && gemfile[%r(gemfiles/(.*?)/)] && $1
 
-SimpleCov.command_name(adapter)
-SimpleCov.start do
-  add_filter("spec")
+if ENV["COVERAGE"]
+  require "simplecov"
+
+  SimpleCov.command_name(adapter)
+  SimpleCov.start { add_filter("spec") }
 end
 
 require "periscope"