From 394e9fff83faf3cffb0f428fd0cd757e67467020 Mon Sep 17 00:00:00 2001
From: GoalSmashers <jakub@goalsmashers.com>
Date: Tue, 10 Dec 2013 10:18:08 +0100
Subject: [PATCH] Adds an optional callback to CleanCSS#minify method.

---
 History.md          |  1 +
 lib/clean.js        |  6 ++++--
 test/module-test.js | 24 ++++++++++++++++++++++++
 3 files changed, 29 insertions(+), 2 deletions(-)

diff --git a/History.md b/History.md
index 7894e7da..82d5d924 100644
--- a/History.md
+++ b/History.md
@@ -1,6 +1,7 @@
 [2.1.0 / 2013-xx-xx (UNRELEASED)](https://github.com/GoalSmashers/clean-css/compare/v2.0.0...HEAD)
 ==================
 
+* Adds an optional callback to minify method.
 * Deprecates --selectors-merge-mode / selectorsMergeMode in favor to --compatibility / compatibility.
 * Skips empty removal if advanced processing is enabled.
 * Fixed issue [#160](https://github.com/GoalSmashers/clean-css/issues/160) - re-runs optimizer until a clean pass.
diff --git a/lib/clean.js b/lib/clean.js
index 187aaa53..2c3b03f2 100644
--- a/lib/clean.js
+++ b/lib/clean.js
@@ -51,7 +51,7 @@ var CleanCSS = module.exports = function CleanCSS(options) {
   this.lineBreak = process.platform == 'win32' ? '\r\n' : '\n';
 };
 
-CleanCSS.prototype.minify = function(data) {
+CleanCSS.prototype.minify = function(data, callback) {
   var startedAt;
   var stats = this.stats;
   var options = this.options;
@@ -348,5 +348,7 @@ CleanCSS.prototype.minify = function(data) {
     stats.minifiedSize = data.length;
   }
 
-  return data;
+  return callback ?
+    callback.call(this, this.context.errors.length > 0 ? this.context.errors : null, data) :
+    data;
 };
diff --git a/test/module-test.js b/test/module-test.js
index b485ae56..8cce9fa3 100644
--- a/test/module-test.js
+++ b/test/module-test.js
@@ -40,6 +40,30 @@ vows.describe('module tests').addBatch({
       delete CleanCSS.prototype.foo;
     }
   },
+  'with callback passed and no errors': {
+    topic: function() {
+      new CleanCSS().minify('a{color:#f00}', this.callback);
+    },
+    'should correctly set context': function() {
+      assert.equal(true, this instanceof CleanCSS);
+    },
+    'should yield no error': function(errors, minified) {
+      /* jshint unused: false */
+      assert.equal(errors, null);
+    },
+    'should yield minified data': function(errors, minified) {
+      assert.equal(minified, 'a{color:red}');
+    }
+  },
+  'with callback passed and one error': {
+    topic: function() {
+      new CleanCSS().minify('@import "missing.css";', this.callback);
+    },
+    'should yield no error and minify': function(errors, minified) {
+      /* jshint unused: false */
+      assert.equal(errors.length, 1);
+    }
+  },
   'no debug': {
     topic: function() {
       var minifier = new CleanCSS();
-- 
2.34.1