Improve test runner's Minitest integration.

This also adds free mix and matching of directories, files and lines filters.
Like so:

bin/rails test models/post_test.rb test/integration models/person_test.rb:26

You can also mix in a traditional Minitest filter:

bin/rails test test/integration -n /check_it_out/

1 files changed, 28 insertions, 0 deletions

diff --git a/railties/lib/rails/test_unit/test_requirer.rb b/railties/lib/rails/test_unit/test_requirer.rb
new file mode 100644
index 0000000000..84c2256729
--- /dev/null
+++ b/railties/lib/rails/test_unit/test_requirer.rb
@@ -0,0 +1,28 @@
+require 'active_support/core_ext/object/blank'
+require 'rake/file_list'
+
+module Rails
+  class TestRequirer # :nodoc:
+    class << self
+      def require_files(patterns)
+        patterns = expand_patterns(patterns)
+
+        Rake::FileList[patterns.compact.presence || 'test/**/*_test.rb'].to_a.each do |file|
+          require File.expand_path(file)
+        end
+      end
+
+      private
+        def expand_patterns(patterns)
+          patterns.map do |arg|
+            arg = arg.gsub(/:(\d+)?$/, '')
+            if Dir.exist?(arg)
+              "#{arg}/**/*_test.rb"
+            elsif File.file?(arg)
+              arg
+            end
+          end
+        end
+    end
+  end
+end