feat: impl text parser support encoding: false (#64)

text parser support with no decoder,
to get buffer instead of string.

lib/text.js

@@ -26,7 +26,7 @@ module.exports = function(req, opts){
   var len = req.headers['content-length'];
   var encoding = req.headers['content-encoding'] || 'identity';
   if (len && encoding === 'identity') opts.length = ~~len;
-  opts.encoding = opts.encoding || 'utf8';
+  opts.encoding = opts.encoding === undefined ? 'utf8': opts.encoding;
   opts.limit = opts.limit || '1mb';
 
   // raw-body returns a Promise when no callback is specified

test/text.js

@@ -2,6 +2,7 @@
 var request = require('supertest');
 var parse = require('..');
 var koa = require('koa');
+var Buffer = require('buffer').Buffer;
 
 describe('parse.text(req, opts)', function(){
   describe('with valid str', function(){
@@ -52,4 +53,21 @@ describe('parse.text(req, opts)', function(){
       .expect(200, done);
     });
   })
+
+  describe('use no encoding', function(){
+    it('should return raw body when opts.returnRawBody = true', function(done){
+      var app = koa();
+
+      app.use(function *(){
+        const requestBody = yield parse.text(this, {encoding: false});
+        this.body = { isBuffer: Buffer.isBuffer(requestBody) };
+      });
+
+      request(app.listen())
+        .post('/')
+        .send('Hello World!')
+        .expect({ isBuffer: true })
+        .expect(200, done);
+    });
+  })
 });