Created AS::Testing::Isolation which runs each test case in a separate process.

	This allows for testing rails bootup (files are required, correct constants are
	set, etc...). Currently, this is implemented via forking only, but we will add 
	support for jruby and windows shortly.

2 files changed, 40 insertions, 0 deletions

diff --git a/activesupport/lib/active_support/test_case.rb b/activesupport/lib/active_support/test_case.rb
index bab2a401eb..e99a4854ce 100644
--- a/activesupport/lib/active_support/test_case.rb
+++ b/activesupport/lib/active_support/test_case.rb
@@ -13,6 +13,7 @@ require 'active_support/testing/assertions'
 require 'active_support/testing/deprecation'
 require 'active_support/testing/declarative'
 require 'active_support/testing/pending'
+require 'active_support/testing/isolation'
 
 module ActiveSupport
   class TestCase < ::Test::Unit::TestCase
diff --git a/activesupport/lib/active_support/testing/isolation.rb b/activesupport/lib/active_support/testing/isolation.rb
new file mode 100644
index 0000000000..8b2957fbe1
--- /dev/null
+++ b/activesupport/lib/active_support/testing/isolation.rb
@@ -0,0 +1,39 @@
+module ActiveSupport::Testing
+  class ProxyTestResult
+    def initialize
+      @calls = []
+    end
+
+    def __replay__(result)
+      @calls.each do |name, args|
+        result.send(name, *args)
+      end
+    end
+
+    def method_missing(name, *args)
+      @calls << [name, args]
+    end
+  end
+
+  module Isolation
+    def run(result)
+      yield(Test::Unit::TestCase::STARTED, name)
+
+      read, write = IO.pipe
+
+      pid = fork do
+        # child
+        read.close
+        proxy = ProxyTestResult.new
+        super(proxy) { }
+        write.puts [Marshal.dump(proxy)].pack("m")
+        exit!
+      end
+
+      write.close
+      Marshal.load(read.read.unpack("m")[0]).__replay__(result)
+      Process.wait2(pid)
+      yield(Test::Unit::TestCase::FINISHED, name)
+    end
+  end
+end
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