Add SimpleCov coverage set up for gRPC ruby

src/ruby/.rspec

 -I.
+--require spec_helper

src/ruby/Rakefile

@@ -26,6 +26,7 @@ namespace :suite do
   SPEC_SUITES.each do |suite|
     desc "Run all specs in the #{suite[:title]} spec suite"
     RSpec::Core::RakeTask.new(suite[:id]) do |t|
+      ENV['COVERAGE_NAME'] = suite[:id].to_s
       spec_files = []
       suite[:files].each { |f| spec_files += Dir[f] } if suite[:files]
 

src/ruby/grpc.gemspec

@@ -27,6 +27,7 @@ Gem::Specification.new do |s|
   s.add_dependency 'minitest', '~> 5.4'  # reqd for interop tests
   s.add_dependency 'xray', '~> 1.1'
 
+  s.add_development_dependency 'simplecov', '~> 0.9'
   s.add_development_dependency 'bundler', '~> 1.9'
   s.add_development_dependency 'rake', '~> 10.4'
   s.add_development_dependency 'rake-compiler', '~> 0.9'

src/ruby/spec/spec_helper.rb

@@ -35,14 +35,18 @@ $LOAD_PATH.unshift(spec_dir)
 $LOAD_PATH.unshift(lib_dir)
 $LOAD_PATH.uniq!
 
-require 'faraday'
+# set up coverage
+require 'simplecov'
+SimpleCov.start do
+  add_filter 'spec'
+  add_filter 'bin'
+  SimpleCov.command_name ENV['COVERAGE_NAME']
+end if ENV['COVERAGE_NAME']
+
 require 'rspec'
 require 'logging'
 require 'rspec/logging_helper'
 
-# Allow Faraday to support test stubs
-Faraday::Adapter.load_middleware(:test)
-
 # Configure RSpec to capture log messages for each test. The output from the
 # logs will be stored in the @log_output variable. It is a StringIO instance.
 RSpec.configure do |config|