Extract ExecJS::Runtime

lib/execjs.rb

@@ -3,6 +3,7 @@ module ExecJS
   class RuntimeError    < Error; end
   class ProgramError    < Error; end
 
+  autoload :Runtime,  "execjs/runtime"
   autoload :Runtimes, "execjs/runtimes"
 
   def self.exec(source)
@@ -14,6 +15,6 @@ module ExecJS
   end
 
   def self.runtime
-    @runtime ||= Runtimes::Node
+    @runtime ||= Runtimes::Node.new
   end
 end

lib/execjs/runtime.rb

@@ -0,0 +1,54 @@
+require "json"
+require "tempfile"
+
+module ExecJS
+  class Runtime
+    def exec(source)
+      compile_to_tempfile(source) do |file|
+        extract_result(exec_runtime(file.path))
+      end
+    end
+
+    def eval(source)
+      if /\S/ =~ source
+        exec("return eval(#{"(#{source})".to_json})")
+      end
+    end
+
+    protected
+      def compile(source)
+        runner_source.sub('#{source}', source)
+      end
+
+      def runner_source
+        @runner_source ||= IO.read(runner_path)
+      end
+
+      def compile_to_tempfile(source)
+        tempfile = Tempfile.open("execjs")
+        tempfile.write compile(source)
+        tempfile.close
+        yield tempfile
+      ensure
+        tempfile.close!
+      end
+
+      def exec_runtime(filename)
+        output = `#{command(filename)} 2>&1`
+        if $?.success?
+          output
+        else
+          raise RuntimeError, output
+        end
+      end
+
+      def extract_result(output)
+        status, value = output.empty? ? [] : JSON.parse(output)
+        if status == "ok"
+          value
+        else
+          raise ProgramError, value
+        end
+      end
+  end
+end

lib/execjs/runtimes/node.rb

@@ -1,57 +1,12 @@
-require "json"
-require "tempfile"
-
 module ExecJS
   module Runtimes
-    module Node
-      extend self
-
-      def exec(source)
-        compile_to_tempfile(source) do |file|
-          extract_result(exec_runtime("node #{file.path}"))
-        end
+    class Node < Runtime
+      def command(filename)
+        "node #{filename}"
       end
 
-      def eval(source)
-        if /\S/ =~ source
-          exec("return eval(#{"(#{source})".to_json})")
-        end
-      end
-
-      protected
-        def compile_to_tempfile(source)
-          tempfile = Tempfile.open("execjs")
-          tempfile.write compile(source)
-          tempfile.close
-          yield tempfile
-        ensure
-          tempfile.close!
-        end
-
-        def compile(source)
-          wrapper.sub('#{source}', source)
-        end
-
-        def wrapper
-          @wrapper ||= IO.read(File.expand_path('../node.js', __FILE__))
-        end
-
-        def exec_runtime(command)
-          output = `#{command} 2>&1`
-          if $?.success?
-            output
-          else
-            raise RuntimeError, output
-          end
-        end
-
-        def extract_result(output)
-          status, value = output.empty? ? [] : JSON.parse(output)
-          if status == "ok"
-            value
-          else
-            raise ProgramError, value
-          end
+      def runner_path
+        File.expand_path('../node.js', __FILE__)
       end
     end
   end

test/test_node_runtime.rb

@@ -3,7 +3,7 @@ require "test/unit"
 
 class TestNodeRuntime < Test::Unit::TestCase
   def setup
-    @runtime = ExecJS::Runtimes::Node
+    @runtime = ExecJS::Runtimes::Node.new
   end
 
   def test_exec