diff --git a/build b/build
index fc9d2cae..b85b38c1 160000
--- a/build
+++ b/build
@@ -1 +1 @@
-Subproject commit fc9d2cae9fe8e6e95e74c86a31d21caadd8f9f39
+Subproject commit b85b38c1e33e161826f4dd7774ef73aac55e0d14
diff --git a/lib/ace/ext/whitespace_test.js b/lib/ace/ext/whitespace_test.js
new file mode 100644
index 00000000..be4f360f
--- /dev/null
+++ b/lib/ace/ext/whitespace_test.js
@@ -0,0 +1,116 @@
+if (typeof process !== "undefined") {
+    require("amd-loader");
+    require("../test/mockdom");
+}
+
+define(function(require, exports, module) {
+"use strict";
+
+var assert = require("assert");
+var EditSession = require("../edit_session").EditSession;
+var whitespace = require("./whitespace");
+
+// Execution ORDER: test.setUpSuite, setUp, testFn, tearDown, test.tearDownSuite
+module.exports = {
+    timeout: 10000,
+
+    "test tab detection": function(next) {
+        var s = new EditSession([
+            "define({",
+            "\tfoo:1,",
+            "\tbar:2,",
+            "\tbaz:{,",
+            "\t\tx:3",
+            "\t}",
+            "})"
+        ]);
+         
+        var indent = whitespace.$detectIndentation(s.doc.$lines);
+        assert.equal(indent.ch, "\t");
+        assert.equal(indent.length, undefined);
+        
+        s.insert({row: 0, column: 0}, "    ");
+        indent = whitespace.$detectIndentation(s.doc.$lines);
+        assert.equal(indent.ch, "\t");
+        assert.equal(indent.length, 4);
+        
+        s.setValue("");
+        indent = whitespace.$detectIndentation(s.doc.$lines);
+        assert.ok(!indent);
+        
+        next();
+    },
+
+    "test empty session": function(next) {
+        var s = new EditSession([
+            "define({",
+            "foo:1,",
+            "})"
+        ]);
+        var indent = whitespace.$detectIndentation(s.doc.$lines);
+        assert.ok(!indent);
+        s.insert({row: 1, column: 0}, "    x\n    ");
+        
+        indent = whitespace.$detectIndentation(s.doc.$lines);
+        assert.equal(indent.ch, " ");
+        assert.equal(indent.length, 4);
+        
+        next();
+    },
+    
+    "!test one line": function(next) {
+        var s = new EditSession([
+            "define({",
+            "    foo:1,",
+            "})"
+        ]);
+        var indent = whitespace.$detectIndentation(s.doc.$lines);
+        assert.equal(indent.ch, " ");
+        assert.equal(indent.length, 4);
+        
+        next();
+    },
+    
+    "test 1 width indents": function(next) {
+        var s = new EditSession([
+            "define({",
+            "    foo:1,",
+            "})",
+            "define({",
+            "    bar:1,",
+            "})",
+            "     t",
+            "      t",
+            "     t",
+            "      t",
+            "     t",
+            "      t",
+            "     t",
+            "      t"
+        ]);
+        var indent = whitespace.$detectIndentation(s.doc.$lines);
+        // assert.equal(indent.ch, " ");
+        // assert.equal(indent.length, 4);
+        
+        s = new EditSession([
+            "{",
+            " foo:1,",
+            " bar: {",
+            "  baz:2",
+            " }",
+            "}"
+        ]);
+        indent = whitespace.$detectIndentation(s.doc.$lines);
+        assert.equal(indent.ch, " ");
+        assert.equal(indent.length, 1);
+        
+        next();
+    },
+
+};
+
+});
+
+if (typeof module !== "undefined" && module === require.main) {
+    require("asyncjs").test.testcase(module.exports).exec();
+}