Merge pull request #26 from YetiOr/master

No need in Duplex stream. Rewrite to Readable.

lib/index.js

@@ -1,13 +1,13 @@
 var fs = require('fs'),
     path = require('path'),
     bemNaming = require('bem-naming'),
-    PassThrough = require('stream').PassThrough,
+    Readable = require('stream').Readable,
     schemes = require('./schemes');
 
 module.exports = function (levels, options) {
     options || (options = {});
 
-    var output = new PassThrough({ objectMode: true }),
+    var output = new Readable({ objectMode: true }),
         defaultScheme = options.scheme || schemes.nested,
         defaultNaming = options.naming ? bemNaming(options.naming) : bemNaming;
 
@@ -27,7 +27,7 @@ module.exports = function (levels, options) {
     });
 
     function add(obj) {
-        output.write(obj);
+        output.push(obj);
     }
 
     function scan(level, callback) {
@@ -72,22 +72,16 @@ module.exports = function (levels, options) {
         }
     }
 
-    var n = 0,
-        l = levels.length;
+    var n = levels.length;
 
-    if (l === 0) {
-        output.end();
-    } else {
-        for (var i = 0; i < l; ++i) {
-            scan(levels[i], scancb);
-        }
-    }
+    output._read = function () {
+        n || output.push(null);
 
-    function scancb(err) {
-        err && output.emit('error', err);
-
-        ++n === l && output.end();
-    }
+        levels.length && scan(levels.shift(), function (err) {
+            err && output.emit('error', err);
+            --n || output.push(null);
+        });
+    };
 
     return output;
 };

test/schemes/flat.test.js

@@ -22,11 +22,12 @@ describe('flat scheme', function () {
     it('must throw error if levels is not found', function (done) {
         var walker = walk(['not-existing-level']);
 
-        walker.on('error', function (err) {
-            err.must.throw();
-            done();
-        })
-        .resume();
+        walker
+            .on('error', function (err) {
+                err.must.throw();
+                done();
+            })
+            .resume();
     });
 
     describe('ignore', function () {

test/schemes/nested.test.js

@@ -22,11 +22,12 @@ describe('nested scheme', function () {
     it('must throw error if levels is not found', function (done) {
         var walker = walk(['not-existing-level']);
 
-        walker.on('error', function (err) {
-            err.must.throw();
-            done();
-        })
-        .resume();
+        walker
+            .on('error', function (err) {
+                err.must.throw();
+                done();
+            })
+            .resume();
     });
 
     describe('ignore', function () {