add tests for both the stream

src/test/progress-stream-test.js

@@ -0,0 +1,25 @@
+/* global it:false */
+/* global describe:false */
+
+'use strict';
+
+const expect = require('expect.js'),
+    fs = require('fs'),
+    ProgressStream = require('../progress-stream.js'),
+    stream = require('stream');
+
+describe('progress stream', function () {
+    it('can create stream', function (done) {
+        const input = fs.createReadStream(`${__dirname}/progress-stream-test.js`);
+        const progress = new ProgressStream({ interval: 1000 });
+        const output = fs.createWriteStream('/dev/null');
+
+        stream.pipeline(input, progress, output, function (error) {
+            expect(error).to.not.be.ok();
+            const size = fs.statSync(`${__dirname}/progress-stream-test.js`).size;
+            expect(progress._transferred).to.be(size);
+
+            done();
+        });
+    });
+});