Support for binary and JSON response data (responseType other than 'text')

.editorconfig

@@ -0,0 +1,9 @@
+# http://editorconfig.org
+root                     = true
+[*]
+indent_style             = space
+indent_size              = 2
+end_of_line              = lf
+charset                  = utf-8
+trim_trailing_whitespace = true
+insert_final_newline     = true

lib/index.js

@@ -24,7 +24,11 @@ var supportedResponseTypes = Object.freeze({
   /** Text response (implicit) */
   '': true,
   /** Text response */
-  'text': true
+  'text': true,
+  /** Binary-data response */
+  'arraybuffer': true,
+  /** JSON response */
+  'json': true
 });
 
 /**
@@ -139,6 +143,14 @@ module.exports = function () {
    * @type {?String}
    */
   this._responseText = null;
+
+  /**
+   * @see https://developer.mozilla.org/en-US/docs/Web/API/XMLHttpRequest/response
+   *
+   * @private
+   * @type {ArrayBuffer | String | Object}
+   */
+  this._response = null;
 };
 
 /** @alias module:node-http-xhr */
@@ -297,7 +309,17 @@ NodeHttpXHR.prototype = Object.create(
           throw new Error('Unsupported responseType "' + type + '"');
         }
 
-        return this._responseText;
+        switch (type) {
+        case '':
+        case 'text':
+          return this._responseText;
+        case 'json':
+          return JSON.parse(this._responseText);
+        case 'arraybuffer':
+          return this._response.buffer;
+        default:
+          throw new Error('Assertion failed: unsupported response-type: ' + type);
+        }
       }
     },
     /**
@@ -308,10 +330,19 @@ NodeHttpXHR.prototype = Object.create(
      * This will be incomplete until the response actually finishes.
      *
      * @type {?String}
+     * @throws when `response` not a String
      * @readonly
      */
     responseText: {
-      get: function getResponseText() { return this._responseText; }
+      get: function getResponseText() {
+
+        // @see https://developer.mozilla.org/en-US/docs/Web/API/XMLHttpRequest/responseText#Exceptions
+        if (this._responseType !== 'text' && this._responseType !== '') {
+          throw new Error('InvalidStateError: Response-type is ' + this._responseType);
+        }
+
+        return this._responseText;
+      }
     },
     /**
      * Indicates whether or not cross-site `Access-Control` requests should be
@@ -469,13 +500,33 @@ NodeHttpXHR.prototype.send = function (data) {
     this._resp = resp;
     this._responseText = '';
 
-    resp.setEncoding('utf8');
+    // var contentType = resp.headers['content-type'];
+    // TODO: adjust responseType from content-type header if applicable
+
+    // from Node API docs: The encoding argument is optional and only applies when chunk is a string. Defaults to 'utf8'.
+    if (this._responseType === 'text' || this._responseType === '') {
+      resp.setEncoding('utf8');
+    }
+
     resp.on('data', function onData(chunk) {
-      this._responseText += chunk;
+
+      if (typeof chunk === 'string') {
+        this._responseText += chunk;
+      } else if (typeof chunk === 'object') {
+        if (!(chunk instanceof Buffer)) {
+          throw new Error('Assertion failed: Response-data should be of `Buffer` type');
+        }
+        if (this._response) {
+          this._response = Buffer.concat([this._response, chunk]);
+        } else {
+          this._response = chunk;
+        }
+      }
 
       if (this.readyState !== this.LOADING) {
         this._setReadyState(this.LOADING);
       }
+
     }.bind(this));
 
     resp.on('end', function onEnd() {

test/index.test.js

@@ -413,6 +413,31 @@ function describeXHRProps() {
     });
 
     describe('#responseType', function () {
+
+      it('supports binary data (arraybuffer responseType)', function (done) {
+
+        var responseData = new Buffer(909);
+
+        var binaryScope = nock('http://example.com')
+          .get('/music.mp3')
+          .reply(200, responseData, {
+            'Content-Type': 'audio/mpeg'
+          });
+
+        req.responseType = 'arraybuffer';
+        req.open('GET', 'http://example.com/music.mp3');
+        req.send();
+
+        req.onload = function () {
+
+          assume(req.responseType).equals('arraybuffer');
+          assume(req.response).equals(responseData.buffer);
+
+          binaryScope.done();
+          done();
+        };
+      });
+
       it('intially is `\'\'`', function () {
         assume(req.responseType).equals('');
       });