Adding support for URLSearchParams

lib/utils.js

@@ -142,6 +142,24 @@ function isStream(val) {
   return isObject(val) && isFunction(val.pipe);
 }
 
+/**
+ * Determine if a value is a URLSearchParams object
+ *
+ * @param {Object} val The value to test
+ * @returns {boolean} True if value is a URLSearchParams object, otherwise false
+ */
+function isURLSearchParams(val) {
+  // Object.prototype.toString will return [object Object] for a polyfill
+  // Hence, we have to use duck typing
+  return toString.call(val) === '[object URLSearchParams]' || (
+    isObject(val) &&
+    isFunction(val.append) &&
+    isFunction(val.delete) &&
+    isFunction(val.get) &&
+    isFunction(val.set)
+  );
+}
+
 /**
  * Trim excess whitespace off the beginning and end of a string
  *
@@ -259,6 +277,7 @@ module.exports = {
   isBlob: isBlob,
   isFunction: isFunction,
   isStream: isStream,
+  isURLSearchParams: isURLSearchParams,
   isStandardBrowserEnv: isStandardBrowserEnv,
   forEach: forEach,
   merge: merge,