Added progress emitter

README.md

@@ -7,10 +7,15 @@ var Counter = require('passthrough-counter')
 
 var stream = fs.createReadStream('package.json')
 var output = fs.createWriteStream('package.json.gz')
+var counter = new Counter();
+
+counter.on('progress', function (length) {
+  // current chunk length
+});
 
 stream
 .pipe(zlib.createGzip())
-.pipe(Counter)
+.pipe(counter)
 .once('finish', function () {
   console.log('final gzipped length is ' + this.length)
 })
@@ -28,6 +33,10 @@ stream
 The total number of bytes pass through the stream.
 You can check this once `finish` is emitted.
 
+### {Event} progress(length)
+
+Event with chunk length emitted each time chunk is received
+
 ## License
 
 The MIT License (MIT)

index.js

@@ -16,5 +16,6 @@ function Counter(options) {
 Counter.prototype._transform = function (chunk, encoding, callback) {
   this.length += chunk.length
   this.push(chunk)
+  this.emit('progress', chunk.length);
   callback()
 }

package.json

@@ -1,7 +1,7 @@
 {
   "name": "passthrough-counter",
   "description": "Get the total buffer length of a stream.",
-  "version": "1.0.0",
+  "version": "1.0.1",
   "author": "Jonathan Ong <[email protected]> (http://jongleberry.com)",
   "license": "MIT",
   "repository": "stream-utils/passthrough-counter",

test/test.js

@@ -18,4 +18,20 @@ describe('Passthrough Counter', function () {
     })
     .resume()
   })
+
+  it('should have progress', function(done) {
+    var stream = fs.createReadStream(pack)
+    var counter = Counter()
+    var currentLength = 0
+
+    counter.on('progress', function (length) {
+      currentLength += length;
+    })
+
+    stream.pipe(counter)
+    .once('finish', function() {
+      assert.equal(currentLength, length);
+      done();
+    });
+  })
 })