refactor: some refactoring in mfs

Author: niinpatel

src/mfs.js

@@ -63,7 +63,7 @@ module.exports = function (options) {
     const readableStream = ipfs.files.readReadableStream(readPath)
 
     readableStream.on('error', (error) => {
-      if (error.toString().indexOf('does not exist') > -1 || error.toString().indexOf('Not a directory') > -1) {
+      if (isNotFoundError(error)) {
         error.notFound = true
       }
     })
@@ -80,15 +80,15 @@ module.exports = function (options) {
 
     log(`stat ${statPath}`)
     ipfs.files.stat(statPath, {}, (error) => {
-      if (error) {
-        if (error.toString().indexOf('does not exist') > -1 || error.toString().indexOf('Not a directory') > -1) {
-          return cb(null, false)
-        }
+      if (!error) {
+        return cb(null, true)
+      }
 
-        return cb(error)
+      if (isNotFoundError(error)) {
+        return cb(null, false)
       }
 
-      cb(null, true)
+      return cb(error)
     })
   }
 
@@ -111,3 +111,7 @@ function noop () {}
 function normalisePath (path) {
   return path.replace(/\/(\/)+/g, '/')
 }
+
+function isNotFoundError (error) {
+  return error.toString().indexOf('does not exist') > -1 || error.toString().indexOf('Not a directory') > -1
+}