Load fixtures only when running suites, or -f

* `rails test -f` will run the test suites with all fixtures loaded
* New application will now generated without `fixtures :all` line
  enabled by default.

railties/CHANGELOG.md

@@ -19,6 +19,14 @@
 
     *Terence Lee*
 
+*   Rails now generate a `test/test_helper.rb` file with `fixtures :all` commented out by default,
+    since we don't want to force loading all fixtures for user when a single test is run. However,
+    fixtures are still going to be loaded automatically for test suites.
+
+    To force all fixtures to be create in your database, use `rails test -f` to run your test.
+
+    *Prem Sichanugrist*
+
 *   Add `rails test` command to run the test suite
 
     To run the whole test suite:

railties/lib/rails/commands/test_runner.rb

@@ -9,7 +9,10 @@ module Rails
       # of file to a new +TestRunner+ object, then invoke the evaluation. If
       # the argument is not a test suite name, it will be treated as a file
       # name and passed to the +TestRunner+ instance right away.
-      def start(files, options)
+      def start(files, options = {})
+        original_fixtures_options = options.delete(:fixtures)
+        options[:fixtures] = true
+
         case files.first
         when nil
           new(Dir['test/**/*_test.rb'], options).run
@@ -28,6 +31,7 @@ module Rails
         when 'integration'
           new(Dir['test/integration/**/*_test.rb'], options).run
         else
+          options[:fixtures] = original_fixtures_options
           new(files, options).run
         end
       end
@@ -52,6 +56,10 @@ module Rails
             exit
           end
 
+          opts.on '-f', '--fixtures', 'Load fixtures in test/fixtures/ before running the tests' do
+            options[:fixtures] = true
+          end
+
           opts.on '-s', '--seed SEED', Integer, "Sets random seed" do |m|
             options[:seed] = m.to_i
           end
@@ -87,6 +95,15 @@ module Rails
     def initialize(files, options)
       @files = files
       Rake::Task['test:prepare'].invoke
+
+      if options.delete(:fixtures)
+        if defined?(ActiveRecord::Base)
+          ActiveSupport::TestCase.send :include, ActiveRecord::TestFixtures
+          ActiveSupport::TestCase.fixture_path = "#{Rails.root}/test/fixtures/"
+          ActiveSupport::TestCase.fixtures :all
+        end
+      end
+
       MiniTest::Unit.runner.options = options
       MiniTest::Unit.output = SilentUntilSyncStream.new(MiniTest::Unit.output)
     end

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

@@ -6,11 +6,12 @@ class ActiveSupport::TestCase
 <% unless  options[:skip_active_record] -%>
   ActiveRecord::Migration.check_pending!
 
-  # Setup all fixtures in test/fixtures/*.yml for all tests in alphabetical order.
+  # Uncomment the `fixtures` line below to setup all fixtures in test/fixtures/*.yml for all tests
+  # in alphabetical order.
   #
   # Note: You'll currently still have to declare fixtures explicitly in integration tests
   # -- they do not yet inherit this setting
-  fixtures :all
+  # fixtures :all
 
 <% end  -%>
   # Add more helper methods to be used by all tests here...

railties/test/application/test_runner_test.rb

@@ -1,4 +1,5 @@
 require 'isolation/abstract_unit'
+require 'active_support/core_ext/string/strip'
 
 module ApplicationTests
   class TestRunnerTest < ActiveSupport::TestCase
@@ -170,11 +171,61 @@ module ApplicationTests
       end
     end
 
+    def test_not_load_fixtures_when_running_single_test
+      create_model_with_fixture
+      create_fixture_test :models, 'user'
+      assert_match /0 users/, run_test_command('test/models/user_test.rb')
+      assert_match /3 users/, run_test_command('test/models/user_test.rb -f')
+    end
+
+    def test_load_fixtures_when_running_test_suites
+      create_model_with_fixture
+      types = [:models, :helpers, [:units, :unit], :controllers, :mailers,
+        [:functionals, :functional], :integration]
+
+      types.each do |type, directory|
+        directory ||= type
+        create_fixture_test directory
+        assert_match /3 users/, run_test_command(type)
+        Dir.chdir(app_path) { FileUtils.rm_f "test/#{directory}" }
+      end
+    end
+
     private
       def run_test_command(arguments = 'test/unit/test_test.rb')
         Dir.chdir(app_path) { `bundle exec rails test #{arguments}` }
       end
 
+      def create_model_with_fixture
+        script 'generate model user name:string'
+
+        app_file 'test/fixtures/users.yml', <<-YAML.strip_heredoc
+          vampire:
+            id: 1
+            name: Koyomi Araragi
+          crab:
+            id: 2
+            name: Senjougahara Hitagi
+          cat:
+            id: 3
+            name: Tsubasa Hanekawa
+        YAML
+
+        Dir.chdir(app_path) { `bundle exec rake db:migrate` }
+      end
+
+      def create_fixture_test(path = :unit, name = 'test')
+        app_file "test/#{path}/#{name}_test.rb", <<-RUBY
+          require 'test_helper'
+
+          class #{name.camelize}Test < ActiveSupport::TestCase
+            def test_fixture
+              puts "\#{User.count} users (\#{__FILE__})"
+            end
+          end
+        RUBY
+      end
+
       def create_schema
         app_file 'db/schema.rb', ''
       end