use directories for structure

node_modules/replace-ext/index.js

@@ -0,0 +1,33 @@
+'use strict';
+
+var path = require('path');
+
+function replaceExt(npath, ext) {
+  if (typeof npath !== 'string') {
+    return npath;
+  }
+
+  if (npath.length === 0) {
+    return npath;
+  }
+
+  var nFileName = path.basename(npath, path.extname(npath)) + ext;
+  var nFilepath = path.join(path.dirname(npath), nFileName);
+
+  // Because `path.join` removes the head './' from the given path.
+  // This removal can cause a problem when passing the result to `require` or
+  // `import`.
+  if (startsWithSingleDot(npath)) {
+    return '.' + path.sep + nFilepath;
+  }
+
+  return nFilepath;
+}
+
+function startsWithSingleDot(fpath) {
+  var first2chars = fpath.slice(0, 2);
+  return (first2chars === '.' + path.sep) ||
+         (first2chars === './');
+}
+
+module.exports = replaceExt;