Load SimpleCov before rspec to collect coverage correctly

.simplecov_spawn.rb

@@ -6,6 +6,10 @@
 
   SimpleCov.command_name 'spawn'
   SimpleCov.at_fork.call(Process.pid)
-  SimpleCov.formatter SimpleCov::Formatter::CoberturaFormatter
-  SimpleCov.start
+  SimpleCov.formatter SimpleCov::Formatter::MultiFormatter.new([
+    SimpleCov::Formatter::CoberturaFormatter,
+  ])
+  SimpleCov.start do |pid|
+    add_filter "/spec/"
+  end
 end

scripts/rspec

@@ -0,0 +1,10 @@
+#!/usr/bin/env ruby
+
+# (The MIT License)
+# Copyright (c) 2012 Chad Humphries, David Chelimsky, Myron Marston
+# Copyright (c) 2009 Chad Humphries, David Chelimsky
+# Copyright (c) 2006 David Chelimsky, The RSpec Development Team
+# Copyright (c) 2005 Steven Baker
+
+require 'rspec/core'
+RSpec::Core::Runner.invoke

scripts/rspec_with_simplecov

@@ -0,0 +1,48 @@
+#!/usr/bin/env ruby
+
+# (The MIT License)
+# Copyright (c) 2012 Chad Humphries, David Chelimsky, Myron Marston
+# Copyright (c) 2009 Chad Humphries, David Chelimsky
+# Copyright (c) 2006 David Chelimsky, The RSpec Development Team
+# Copyright (c) 2005 Steven Baker
+
+# Turn on verbose to make sure we not generating any ruby warning
+$VERBOSE = true
+
+# So our "did they run the rspec command?" detection logic thinks
+# that we run `rspec`.
+$0 = "rspec"
+
+# This is necessary for when `--standalone` is being used.
+$:.unshift File.expand_path '../../bundle', __FILE__
+
+# For the travis build we put the bundle directory up a directory
+# so it can be shared among the repos for faster bundle installs.
+$:.unshift File.expand_path '../../../bundle', __FILE__
+
+require 'bundler/setup'
+
+# To use simplecov while running rspec-core's test suite, we must
+# load simplecov _before_ loading any of rspec-core's files.
+# So, this executable exists purely as a wrapper script that
+# first loads simplecov, and then loads rspec.
+begin
+  # Simplecov emits some ruby warnings when loaded, so silence them.
+  old_verbose, $VERBOSE = $VERBOSE, false
+
+  unless ENV['NO_COVERAGE'] || RUBY_VERSION < '1.9.3'
+    require 'simplecov'
+
+    SimpleCov.start do
+      add_filter "./bundle/"
+      add_filter "./tmp/"
+      add_filter "./spec/"
+      minimum_coverage(RUBY_PLATFORM == 'java' ? 94 : 97)
+    end
+  end
+rescue LoadError
+ensure
+  $VERBOSE = old_verbose
+end
+
+load File.expand_path("../rspec", __FILE__)

spec/spec_helper.rb

@@ -14,7 +14,10 @@ def assert_run(*args)
   end
 
   def run_tests(*args, command:, openapi: false, output: :yaml)
-    env = { 'OPENAPI' => ('1' if openapi), 'OPENAPI_OUTPUT' => output.to_s }.compact
+    env = {
+      'OPENAPI' => ('1' if openapi),
+      'OPENAPI_OUTPUT' => output.to_s,
+    }.compact
     Bundler.public_send(Bundler.respond_to?(:with_unbundled_env) ? :with_unbundled_env : :with_clean_env) do
       Dir.chdir(repo_root) do
         assert_run env, 'bundle', 'exec', command, '-r./.simplecov_spawn', *args
@@ -23,7 +26,7 @@ def run_tests(*args, command:, openapi: false, output: :yaml)
   end
 
   def rspec(*args, openapi: false, output: :yaml)
-    run_tests(*args, command: 'rspec', openapi: openapi, output: output)
+    run_tests(*args, command: 'scripts/rspec_with_simplecov', openapi: openapi, output: output)
   end
 
   def minitest(*args, openapi: false, output: :yaml)