adding Johnson.require()

lib/prelude.js

@@ -38,4 +38,19 @@ Johnson.Generator.create = function() {
   return new Johnson.Generator(this);
 }
 
+Johnson.required = {};
+
+Johnson.require = function(file) {
+  if(Johnson.required[file]) return false;
+  for(var directory in Ruby['$LOAD_PATH']) {
+    var filename = directory + "/" + Ruby.File.basename(file, ".js") + ".js";
+    if(Ruby.File['exists?'](filename)) {
+      Johnson.required[file] = true;
+      eval(Ruby.File.read(filename));
+      return true;
+    }
+  }
+  throw FileNotFound;
+}
+
 null; // no need to marshal a result

test/johnson/spidermonkey/js_land_proxy_test.rb

@@ -65,6 +65,21 @@ def setup
       def test_find_constants
         assert_js_equal($LOAD_PATH, "Ruby['$LOAD_PATH']")
       end
+
+      def test_require_twice
+        assert @context.evaluate('Johnson.require("prelude")')
+        assert !@context.evaluate('Johnson.require("prelude")')
+      end
+
+      def test_catch_missing_require
+        assert @context.evaluate("
+          try {
+            Johnson.require('adkfjhasd');
+          } catch(FileNotFound) {
+            true;
+          }
+        ")
+      end
 
       def test_array_gets_returned
         list = [1,2,3,4]