add coverage report, set COVERAGE=1 in env when running specs

spec/spec_helper.rb

@@ -1,5 +1,6 @@
 # This file is copied to spec/ when you run 'rails generate rspec:install'
 ENV["RAILS_ENV"] ||= 'test'
+require 'support/coverage' # needs to be first
 require File.expand_path("../../config/environment", __FILE__)
 require 'rspec/rails'
 require 'rspec/autorun'

spec/support/coverage.rb

@@ -0,0 +1,14 @@
+# optional test coverage
+# needs to be loaded first, e.g. add a require at top of spec_helper
+if ENV['COVERAGE']
+  require 'simplecov'
+  SimpleCov.start do
+    add_filter '/spec/'
+    add_filter '/test/'
+    add_group 'Models', '/app/models/'
+    add_group 'Controllers', '/app/controllers/'
+    add_group 'Helpers', '/app/helpers/'
+    add_group 'Documents', '/app/documents/'
+    add_group 'Libraries', '/lib/'
+  end
+end