update to allow passing args to tap

src/tap.coffee

@@ -10,7 +10,11 @@ DEBUG = process.env.NODE_ENV is 'development'
 # Taps into the pipeline and allows user to easily route data through
 # another stream or change content.
 ###
-module.exports = (lambda) ->
+module.exports = () ->
+
+  lambda = arguments[0];
+  lambdaArgs = [].slice.call(arguments, 1);
+
   utils = (tapStream, file) ->
 
     ###
@@ -41,7 +45,7 @@ module.exports = (lambda) ->
 
   modifyFile = (file, enc, cb) ->
     inst = file: file
-    obj = lambda(inst.file, utils(this, inst.file), inst)
+    obj = lambda.apply(null, [inst.file, utils(this, inst.file), inst].concat(lambdaArgs))
 
     next = () =>
       this.push(file)

tests/args.test.coffee

@@ -0,0 +1,36 @@
+fs    = require 'fs'
+path  = require 'path'
+gulp  = require 'gulp'
+tap   = require '../'
+tapTest = require 'tap'
+
+test2 = (file, a, b, test) ->
+  test.ok true
+
+test3 = (file, a, b, test, value) ->
+  if value == "my value"
+    test.ok true
+    test.end()
+  else 
+    test.ok false
+    test.end()
+
+# helper function to get a path relative to the root
+getPath = (rel) -> path.resolve __dirname, '..', rel
+
+tapTest.test "works with passing 0, 1, n args to tap", (test) ->
+
+    test.plan 3
+
+    fixturePath = getPath 'tests/fixtures/'
+
+    gulp.src fixturePath + '/js.js'
+      .pipe tap (file) ->
+        test.ok true
+
+    gulp.src fixturePath + '/js.js'
+      .pipe tap test2, test
+
+    gulp.src fixturePath + '/js.js'
+      .pipe tap test3, test, "my value"
+