Refactor tests that switch RAILS_ENV and RACK_ENV

This cleanup aims to fix a build failure:
https://travis-ci.org/rails/rails/jobs/3515951/#L482

Since travis always have both ENV vars set to "test", a test is failing
where it's expected to output the default env "development", but "test"
is the result due to RACK_ENV being set when we expect it to not be.

By cleaning this duplication we ensure that changing any of these env
variables will pick the right expected value.

1 files changed, 10 insertions, 14 deletions

diff --git a/railties/test/commands/server_test.rb b/railties/test/commands/server_test.rb
index 6a75207ebb..cb57b3c0cd 100644
--- a/railties/test/commands/server_test.rb
+++ b/railties/test/commands/server_test.rb
@@ -1,7 +1,9 @@
 require 'abstract_unit'
+require 'env_helpers'
 require 'rails/commands/server'
 
 class Rails::ServerTest < ActiveSupport::TestCase
+  include EnvHelpers
 
   def test_environment_with_server_option
     args    = ["thin", "-e", "production"]
@@ -25,22 +27,16 @@ class Rails::ServerTest < ActiveSupport::TestCase
   end
 
   def test_environment_with_rails_env
-    rails = ENV['RAILS_ENV']
-    ENV['RAILS_ENV'] = 'production'
-    server = Rails::Server.new
-    assert_equal 'production', server.options[:environment]
-  ensure
-    ENV['RAILS_ENV'] = rails
+    with_rails_env 'production' do
+      server = Rails::Server.new
+      assert_equal 'production', server.options[:environment]
+    end
   end
 
   def test_environment_with_rack_env
-    rack, rails = ENV['RACK_ENV'], ENV['RAILS_ENV']
-    ENV['RAILS_ENV'] = nil
-    ENV['RACK_ENV'] = 'production'
-    server = Rails::Server.new
-    assert_equal 'production', server.options[:environment]
-  ensure
-    ENV['RACK_ENV'] = rack
-    ENV['RAILS_ENV'] = rails
+    with_rack_env 'production' do
+      server = Rails::Server.new
+      assert_equal 'production', server.options[:environment]
+    end
   end
 end