Use to-arraybuffer instead of manual conversion

This fixes some more edge cases when converting from a Buffer to
an ArrayBuffer.

Additionally, compared v2.0.5, this avoids an unnecessary copy
when sending data in a request body.

Author: jhiesey

lib/request.js

@@ -3,6 +3,7 @@ var capability = require('./capability')
 var inherits = require('inherits')
 var response = require('./response')
 var stream = require('stream')
+var toArrayBuffer = require('to-arraybuffer')
 
 var IncomingMessage = response.IncomingMessage
 var rStates = response.readyStates
@@ -96,15 +97,7 @@ ClientRequest.prototype._onFinish = function () {
 	if (opts.method === 'POST' || opts.method === 'PUT' || opts.method === 'PATCH') {
 		if (capability.blobConstructor) {
 			body = new global.Blob(self._body.map(function (buffer) {
-				if (buffer instanceof Uint8Array) {
-					return buffer
-				} else {
-					var buf = new Uint8Array(buffer.length)
-					for (var i = 0, len = buf.length; i < len; i++) {
-						buf[i] = buffer[i]
-					}
-					return buf
-				}
+				return toArrayBuffer(buffer)
 			}), {
 				type: (headersObj['content-type'] || {}).value || ''
 			})

package.json

@@ -25,6 +25,7 @@
   "dependencies": {
     "builtin-status-codes": "^1.0.0",
     "inherits": "^2.0.1",
+    "to-arraybuffer": "^1.0.0",
     "xtend": "^4.0.0"
   },
   "devDependencies": {