perf: remove argument reassignment

.eslintrc

@@ -1,3 +1,6 @@
 {
-  "extends": "standard"
+  "extends": "standard",
+  "rules": {
+    "no-param-reassign": "error"
+  }
 }

HISTORY.md

@@ -2,6 +2,7 @@ unreleased
 ==========
 
   * deps: [email protected]
+  * perf: remove argument reassignment
 
 1.18.1 / 2017-09-12
 ===================

lib/read.js

@@ -74,20 +74,25 @@ function read (req, res, next, parse, debug, options) {
 
   // read body
   debug('read body')
-  getBody(stream, opts, function (err, body) {
-    if (err) {
-      // echo back charset
-      if (err.type === 'encoding.unsupported') {
-        err = createError(415, 'unsupported charset "' + encoding.toUpperCase() + '"', {
+  getBody(stream, opts, function (error, body) {
+    if (error) {
+      var _error
+
+      if (error.type === 'encoding.unsupported') {
+        // echo back charset
+        _error = createError(415, 'unsupported charset "' + encoding.toUpperCase() + '"', {
           charset: encoding.toLowerCase(),
           type: 'charset.unsupported'
         })
+      } else {
+        // set status code on error
+        _error = createError(400, error)
       }
 
       // read off entire request
       stream.resume()
       onFinished(req, function onfinished () {
-        next(createError(400, err))
+        next(createError(400, _error))
       })
       return
     }