Add `rails test` command to run the test suite

To run the whole test suite:

    $ rails test

To run the test file(s):

    $ rails test test/unit/foo_test.rb [test/unit/bar_test.rb ...]

To run the test suite

    $ rails test [models,helpers,units,controllers,mailers,...]

For more information, see `rails test --help`.

This command will eventually replacing `rake test:*`, and `rake test`
command will actually invoking `rails test` instead.

2 files changed, 107 insertions, 0 deletions

diff --git a/railties/lib/rails/commands.rb b/railties/lib/rails/commands.rb
index aacde52cfc..c76af7d01f 100644
--- a/railties/lib/rails/commands.rb
+++ b/railties/lib/rails/commands.rb
@@ -5,6 +5,7 @@ aliases = {
   "d"  => "destroy",
   "c"  => "console",
   "s"  => "server",
+  "t"  => "test",
   "db" => "dbconsole",
   "r"  => "runner"
 }
@@ -16,6 +17,7 @@ The most common rails commands are:
  generate    Generate new code (short-cut alias: "g")
  console     Start the Rails console (short-cut alias: "c")
  server      Start the Rails server (short-cut alias: "s")
+ test        Running the test file (short-cut alias: "t")
  dbconsole   Start a console for the database specified in config/database.yml
              (short-cut alias: "db")
  new         Create a new Rails application. "rails new my_app" creates a
@@ -78,6 +80,19 @@ when 'server'
     server.start
   end
 
+when 'test'
+  $LOAD_PATH.unshift("./test")
+  require 'rails/commands/test_runner'
+  if ["-h", "--help"].include?(ARGV.first)
+    Rails::TestRunner.help_message
+    exit
+  else
+    require APP_PATH
+    Rails.application.require_environment!
+    Rails.application.load_tasks
+    Rails::TestRunner.start(ARGV)
+  end
+
 when 'dbconsole'
   require 'rails/commands/dbconsole'
   Rails::DBConsole.start
diff --git a/railties/lib/rails/commands/test_runner.rb b/railties/lib/rails/commands/test_runner.rb
new file mode 100644
index 0000000000..a65b508505
--- /dev/null
+++ b/railties/lib/rails/commands/test_runner.rb
@@ -0,0 +1,92 @@
+require 'optparse'
+require 'minitest/unit'
+
+module Rails
+  # Handling the all the logic behind +rails test+ command.
+  class TestRunner
+    class << self
+      # Parse the test suite name from the arguments array and pass in a list
+      # 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(arguments)
+        case arguments.first
+        when nil
+          new(Dir['test/**/*_test.rb']).run
+        when 'models'
+          new(Dir['test/models/**/*_test.rb']).run
+        when 'helpers'
+          new(Dir['test/helpers/**/*_test.rb']).run
+        when 'units'
+          new(Dir['test/{models,helpers,unit}/**/*_test.rb']).run
+        when 'controllers'
+          new(Dir['test/controllers/**/*_test.rb']).run
+        when 'mailers'
+          new(Dir['test/mailers/**/*_test.rb']).run
+        when 'functionals'
+          new(Dir['test/{controllers,mailers,functional}/**/*_test.rb']).run
+        when 'integration'
+          new(Dir['test/integration/**/*_test.rb']).run
+        else
+          new(arguments).run
+        end
+      end
+
+      # Print out the help message which listed all of the test suite names.
+      def help_message
+        puts "Usage: rails test [path to test file(s) or test suite type]"
+        puts ""
+        puts "Run single test file, or a test suite, under Rails'"
+        puts "environment. If the file name(s) or suit name is omitted,"
+        puts "Rails will run all the test suites."
+        puts ""
+        puts "Support types of test suites:"
+        puts "-------------------------------------------------------------"
+        puts "* models (test/models/**/*)"
+        puts "* helpers (test/helpers/**/*)"
+        puts "* units (test/{models,helpers,unit}/**/*"
+        puts "* controllers (test/controllers/**/*)"
+        puts "* mailers (test/mailers/**/*)"
+        puts "* functionals (test/{controllers,mailers,functional}/**/*)"
+        puts "* integration (test/integration/**/*)"
+        puts "-------------------------------------------------------------"
+      end
+    end
+
+    # Create a new +TestRunner+ object with a list of test file paths.
+    def initialize(files)
+      @files = files
+      Rake::Task['test:prepare'].invoke
+      MiniTest::Unit.output = SilentUntilSyncStream.new(MiniTest::Unit.output)
+    end
+
+    # Run the test files by evaluate each of them.
+    def run
+      @files.each { |filename| load(filename) }
+    end
+
+    # A null stream object which ignores everything until +sync+ has been set
+    # to true. This is only to be used to silence unnecessary output from
+    # MiniTest, as MiniTest calls +output.sync = true+ right before output the
+    # first test result.
+    class SilentUntilSyncStream < File
+      # Create a +SilentUntilSyncStream+ object by given a stream object that
+      # this stream should set +MiniTest::Unit.output+ to after +sync+ has been
+      # set to true.
+      def initialize(target_stream)
+        @target_stream = target_stream
+        super(File::NULL, 'w')
+      end
+
+      # Swap +MiniTest::Unit.output+ to another stream when +sync+ is true.
+      def sync=(sync)
+        if sync
+          @target_stream.sync = true
+          MiniTest::Unit.output = @target_stream
+        end
+
+        super
+      end
+    end
+  end
+end