chore(getSize): rewrite in ES5 (#24)

lib/api/getSize.js

+var BigInt = require('../tools/bigint');
+var request = require('../tools/smb2-forge').request;
+
+module.exports = function getSize(path, cb) {
+  var connection = this;
+  request('open', { path: path }, connection, function(err, file) {
+    if (err != null) {
+      return cb(err);
+    }
+    request('close', file, connection, function() {
+      cb(null, BigInt.fromBuffer(file.EndofFile).toNumber());
+    });
+  });
+};

lib/api/src/getSize.js

-import { request } from '../tools/smb2-forge';
-
-export default function(path, cb) {
-  request('open', { path }, this, (err, file) => {
-    if (err) {
-      if (err.code === 'STATUS_OBJECT_NAME_NOT_FOUND') {
-        err.code = 'ENOENT';
-      }
-      cb(err);
-    } else {
-      let fileLength = 0;
-      for (let i = 0; i < file.EndofFile.length; i++) {
-        fileLength += file.EndofFile[i] * Math.pow(2, i * 8);
-      }
-      cb(null, fileLength);
-    }
-  });
-}