Tweak build option internals and add test template files.

Former-commit-id: ed5ec6ed7886a066c8c727de19dc0fe6548a276d

build/post-compile.js

@@ -56,13 +56,16 @@
   // expose `postprocess`
   if (module != require.main) {
     module.exports = postprocess;
-  } else {
+  }
+  else {
     // read the Lo-Dash source file from the first argument if the script
     // was invoked directly (e.g. `node post-compile.js source.js`) and write to
     // the same file
     (function() {
-      var source = fs.readFileSync(process.argv[2], 'utf8');
-      fs.writeFileSync(process.argv[2], postprocess(source), 'utf8');
+      var filePath = process.argv[2],
+          source = fs.readFileSync(filePath, 'utf8');
+
+      fs.writeFileSync(filePath, postprocess(source), 'utf8');
     }());
   }
 }());