Expose ieCompat option present in LESS 1.4.0

For more information
less/less.js#1190

Closes gh-53.

Gruntfile.js

@@ -62,6 +62,24 @@ module.exports = function(grunt) {
           'tmp/yuicompress.css': ['test/fixtures/style.less']
         }
       },
+      ieCompatTrue: {
+        options: {
+          paths: ['test/fixtures/include'],
+          ieCompat: true
+        },
+        files: {
+          'tmp/ieCompatTrue.css': ['test/fixtures/ieCompat.less']
+        }
+      },
+      ieCompatFalse: {
+        options: {
+          paths: ['test/fixtures/include'],
+          ieCompat: false
+        },
+        files: {
+          'tmp/ieCompatFalse.css': ['test/fixtures/ieCompat.less']
+        }
+      },
       nofiles: {
       },
       nomatchedfiles: {

README.md

@@ -46,6 +46,14 @@ Default: False
 
 Compress output using cssmin.js
 
+#### ieCompat
+Type: `Boolean`
+Default: true
+
+Enforce the css output is compatible with Internet Explorer 8.
+
+For example, the [data-uri](https://github.com/cloudhead/less.js/pull/1086) function encodes a file in base64 encoding and embeds it into the generated CSS files as a data-URI. Because Internet Explorer 8 limits `data-uri`s to 32KB, the [ieCompat](https://github.com/cloudhead/less.js/pull/1190) option prevents `less` from exceeding this.
+
 #### optimization
 Type: `Integer`
 Default: null
@@ -107,4 +115,4 @@ less: {
 
 Task submitted by [Tyler Kellen](http://goingslowly.com/)
 
-*This file was generated on Sun Jun 09 2013 09:38:44.*
+*This file was generated on Tue Jun 11 2013 16:04:30.*

docs/less-options.md

@@ -18,6 +18,14 @@ Default: False
 
 Compress output using cssmin.js
 
+## ieCompat
+Type: `Boolean`
+Default: true
+
+Enforce the css output is compatible with Internet Explorer 8.
+
+For example, the [data-uri](https://github.com/cloudhead/less.js/pull/1086) function encodes a file in base64 encoding and embeds it into the generated CSS files as a data-URI. Because Internet Explorer 8 limits `data-uri`s to 32KB, the [ieCompat](https://github.com/cloudhead/less.js/pull/1190) option prevents `less` from exceeding this.
+
 ## optimization
 Type: `Integer`
 Default: null

tasks/less.js

@@ -15,7 +15,7 @@ module.exports = function(grunt) {
 
   var lessOptions = {
     parse: ['paths', 'optimization', 'filename', 'strictImports', 'dumpLineNumbers'],
-    render: ['compress', 'yuicompress']
+    render: ['compress', 'yuicompress', 'ieCompat']
   };
 
   grunt.registerMultiTask('less', 'Compile LESS files to CSS', function() {

test/expected/ieCompatTrue.css

@@ -0,0 +1,5 @@
+body {
+  width: 288px;
+  height: 288px;
+  background: transparent url('include/bob.jpg') 0 0 no-repeat;
+}

test/fixtures/ieCompat.less

@@ -0,0 +1,5 @@
+body {
+	width: 288px;
+	height: 288px;
+	background: transparent data-uri('include/bob.jpg') 0 0 no-repeat;
+}

test/less_test.js

@@ -48,6 +48,23 @@ exports.less = {
     var expected = grunt.file.read('test/expected/yuicompress.css');
     test.equal(expected, actual, 'should yuicompress output when yuicompress option is true');
 
+    test.done();
+  },
+  ieCompat: function(test) {
+    'use strict';
+
+	var actual, expected;
+
+    test.expect(2);
+
+	actual = grunt.file.read('tmp/ieCompatFalse.css');
+	expected = grunt.file.read('test/expected/ieCompatFalse.css');
+    test.equal(expected, actual, 'should generate data-uris no matter the size when ieCompat option is true');
+
+	actual = grunt.file.read('tmp/ieCompatTrue.css');
+	expected = grunt.file.read('test/expected/ieCompatTrue.css');
+    test.equal(expected, actual, 'should generate data-uris only when under the 32KB mark for Internet Explorer 8');
+
     test.done();
   }
 };