Make sure that rails test load test in test env

railties/lib/rails/commands.rb

@@ -84,10 +84,9 @@ when 'test'
   $LOAD_PATH.unshift("./test")
   require 'rails/commands/test_runner'
   options = Rails::TestRunner.parse_arguments(ARGV)
+  ENV['RAILS_ENV'] ||= options[:environment] || 'test'
 
   require APP_PATH
-  Rails.application.require_environment!
-  Rails.application.load_tasks
   Rails::TestRunner.start(ARGV, options)
 
 when 'dbconsole'

railties/lib/rails/commands/test_runner.rb

@@ -56,6 +56,10 @@ module Rails
             exit
           end
 
+          opts.on '-e', '--environment NAME', String, 'Specifies the environment to run this test under' do |e|
+            options[:environment] = e
+          end
+
           opts.on '-f', '--fixtures', 'Load fixtures in test/fixtures/ before running the tests' do
             options[:fixtures] = true
           end
@@ -68,8 +72,8 @@ module Rails
             options[:verbose] = true
           end
 
-          opts.on '-n', '--name PATTERN', "Filter test names on pattern (e.g. /foo/)" do |a|
-            options[:filter] = a
+          opts.on '-n', '--name PATTERN', "Filter test names on pattern (e.g. /foo/)" do |n|
+            options[:filter] = n
           end
 
           opts.separator ""
@@ -94,7 +98,9 @@ module Rails
     # Creates a new +TestRunner+ object with a list of test file paths.
     def initialize(files, options)
       @files = files
-      Rake::Task['test:prepare'].invoke
+
+      Rails.application.load_tasks
+      Rake::Task['db:test:load'].invoke
 
       if options.delete(:fixtures)
         if defined?(ActiveRecord::Base)

railties/lib/rails/generators/rails/app/templates/test/test_helper.rb

@@ -1,4 +1,4 @@
-ENV["RAILS_ENV"] = "test"
+ENV["RAILS_ENV"] ||= "test"
 require File.expand_path('../../config/environment', __FILE__)
 require 'rails/test_help'
 

railties/test/application/test_runner_test.rb

@@ -191,6 +191,39 @@ module ApplicationTests
       end
     end
 
+    def test_run_different_environment_using_env_var
+      app_file 'test/unit/env_test.rb', <<-RUBY
+        require 'test_helper'
+
+        class EnvTest < ActiveSupport::TestCase
+          def test_env
+            puts Rails.env
+          end
+        end
+      RUBY
+
+      assert_match /development/, Dir.chdir(app_path) { `RAILS_ENV=development bundle exec rails test test/unit/env_test.rb` }
+    end
+
+    def test_run_different_environment_using_e_tag
+      app_file 'test/unit/env_test.rb', <<-RUBY
+        require 'test_helper'
+
+        class EnvTest < ActiveSupport::TestCase
+          def test_env
+            puts Rails.env
+          end
+        end
+      RUBY
+
+      assert_match /development/, run_test_command('-e development test/unit/env_test.rb')
+    end
+
+    def test_generated_scaffold_works_with_rails_test
+      create_scaffold
+      assert_match /0 failures, 0 errors, 0 skips/, run_test_command('')
+    end
+
     private
       def run_test_command(arguments = 'test/unit/test_test.rb')
         Dir.chdir(app_path) { `bundle exec rails test #{arguments}` }
@@ -211,7 +244,7 @@ module ApplicationTests
             name: Tsubasa Hanekawa
         YAML
 
-        Dir.chdir(app_path) { `bundle exec rake db:migrate` }
+        run_migration
       end
 
       def create_fixture_test(path = :unit, name = 'test')
@@ -251,5 +284,15 @@ module ApplicationTests
           end
         RUBY
       end
+
+      def create_scaffold
+        script 'generate scaffold user name:string'
+        Dir.chdir(app_path) { File.exist?('app/models/user.rb') }
+        run_migration
+      end
+
+      def run_migration
+        Dir.chdir(app_path) { `bundle exec rake db:migrate` }
+      end
   end
 end