use array instead of map

lib/form_data.js

@@ -15,6 +15,33 @@ module.exports = FormData;
 // make it a Stream
 util.inherits(FormData, CombinedStream);
 
+/**
+ * @param {string} name the entry name
+ * @param {string} value the entry value
+ * @returns {Object}
+ */
+function createEntry(name, value/*, filename*/) {
+  // TODO: handle Blob and File
+  // Related to https://xhr.spec.whatwg.org/#concept-formdata-entry
+
+  // Case 1:
+  // If value is a Blob object and not a File object, then set value to a new
+  // File object, representing the same bytes, whose name attribute value is
+  // "blob".
+
+  // Case 2:
+  // If value is (now) a File object and filename is given, then set value to a
+  // new File object, representing the same bytes, whose name attribute value
+  // is filename.
+
+  var entry = {
+    name: name,
+    value: value,
+  };
+
+  return entry;
+}
+
 /**
  * Create readable "multipart/form-data" streams.
  * Can be used to submit forms
@@ -31,7 +58,7 @@ function FormData(options) {
   this._overheadLength = 0;
   this._valueLength = 0;
   this._valuesToMeasure = [];
-  this._entryList = {};
+  this._entryList = [];
 
   CombinedStream.call(this);
 
@@ -78,18 +105,30 @@ FormData.prototype.append = function(field, value, options) {
   // pass along options.knownLength
   this._trackLength(header, value, options);
 
-  if (!this._entryList[field]) {
-    this._entryList[field] = [];
-  }
-  this._entryList[field].push(value);
+  this._entryList.push(createEntry(field, value));
 };
 
 FormData.prototype.get = function(field) {
-  return this._entryList[field] ? this._entryList[field][0] : null;
+  var foundItem = this._entryList.find(function(item) {
+    return item.name === field;
+  });
+
+  if (!foundItem) {
+    return null;
+  }
+
+  return foundItem.value;
 };
 
 FormData.prototype.getAll = function(field) {
-  return this._entryList[field] || [];
+  return this._entryList
+    .filter(function(item) {
+      return item.name === field;
+    })
+    .map(function(item) {
+      return item.value;
+    })
+  ;
 };
 
 FormData.prototype._trackLength = function(header, value, options) {