Code quality (#525)

* prefer template literals

* avoid self = this

* prefer template literals

* split default options into separate file for clarity

lib/default_options.js

@@ -0,0 +1,11 @@
+const defaultOptions = {
+    maxFields: 1000,
+    maxFieldsSize: 20 * 1024 * 1024,
+    maxFileSize: 200 * 1024 * 1024,
+    keepExtensions: false,
+    encoding: 'utf-8',
+    hash: false,
+    multiples: false,
+};
+
+exports.defaultOptions = defaultOptions;

lib/file.js

@@ -52,34 +52,32 @@ File.prototype.toJSON = function() {
 };
 
 File.prototype.toString = function () {
-  return "File:" + this.name + ", Path:" + this.path;
+  return `File: ${this.name}, Path: ${this.path}`;
 };
 
 File.prototype.write = function(buffer, cb) {
-  var self = this;
-  if (self.hash) {
-    self.hash.update(buffer);
+  if (this.hash) {
+    this.hash.update(buffer);
   }
 
   if (this._writeStream.closed) {
     return cb();
   }
 
-  this._writeStream.write(buffer, function() {
-    self.lastModifiedDate = new Date();
-    self.size += buffer.length;
-    self.emit('progress', self.size);
+  this._writeStream.write(buffer, () => {
+    this.lastModifiedDate = new Date();
+    this.size += buffer.length;
+    this.emit('progress', this.size);
     cb();
   });
 };
 
 File.prototype.end = function(cb) {
-  var self = this;
-  if (self.hash) {
-    self.hash = self.hash.digest('hex');
+  if (this.hash) {
+    this.hash = this.hash.digest('hex');
   }
-  this._writeStream.end(function() {
-    self.emit('end');
+  this._writeStream.end(() => {
+    this.emit('end');
     cb();
   });
 };