Fixing response with utf-8 BOM can not parse to json (#2419)

* fix: remove byte order marker (UTF-8 BOM) when transform response

* fix: remove BOM only utf-8

* test: utf-8 BOM

* fix: incorrect param name

Co-authored-by: Jay <jasonsaayman@gmail.com>

lib/utils.js

@@ -312,6 +312,19 @@ function extend(a, b, thisArg) {
   return a;
 }
 
+/**
+ * Remove byte order marker. This catches EF BB BF (the UTF-8 BOM)
+ *
+ * @param {string} content with BOM
+ * @return {string} content value without BOM
+ */
+function stripBOM(content) {
+  if (content.charCodeAt(0) === 0xFEFF) {
+    content = content.slice(1);
+  }
+  return content;
+}
+
 module.exports = {
   isArray: isArray,
   isArrayBuffer: isArrayBuffer,
@@ -333,5 +346,6 @@ module.exports = {
   forEach: forEach,
   merge: merge,
   extend: extend,
-  trim: trim
+  trim: trim,
+  stripBOM: stripBOM
 };