chore: prepare for docs sidebar

lib/load/utils.js

@@ -1,4 +1,6 @@
 const path = require('path');
+const fm = require('front-matter');
+const escapeStringRegexp = require('escape-string-regexp');
 const fs = require('fs-extra');
 
 const genPath = path.resolve(__dirname, '../core/generated');
@@ -40,9 +42,40 @@ function fileToComponentName(file) {
   return ext ? ext.toUpperCase() + str : str;
 }
 
+function idx(target, keyPaths) {
+  return (
+    target &&
+    (Array.isArray(keyPaths)
+      ? keyPaths.reduce((obj, key) => obj && obj[key], target)
+      : target[keyPaths])
+  );
+}
+
+function getSubFolder(file, refDir) {
+  const separator = escapeStringRegexp(path.sep);
+  const baseDir = escapeStringRegexp(path.basename(refDir));
+  const regexSubFolder = new RegExp(
+    `${baseDir}${separator}(.*?)${separator}.*`
+  );
+  const match = regexSubFolder.exec(file);
+  return match && match[1];
+}
+
+function parse(fileString) {
+  if (!fm.test(fileString)) {
+    return {metadata: null, content: fileString};
+  }
+  const {attributes: metadata, body: content} = fm(fileString);
+
+  return {metadata, content};
+}
+
 module.exports = {
   encodePath,
   generate,
   fileToPath,
-  fileToComponentName
+  fileToComponentName,
+  getSubFolder,
+  idx,
+  parse
 };