The file.expand 'filter' option can now be either a string or a funct…

…ion.

* The string has to be a valid a fs.Stats method name.
* The function is synchronous, accepts a relative filepath, and should return true or false.

lib/grunt/file.js

@@ -116,8 +116,12 @@ file.expand = function() {
     matches = matches.filter(function(filepath) {
       filepath = path.join(options.cwd, filepath);
       try {
-        // If the file is of the right type and exists, this should work.
-        return fs.statSync(filepath)[options.filter]();
+        if (typeof options.filter === 'function') {
+          return options.filter(filepath);
+        } else {
+          // If the file is of the right type and exists, this should work.
+          return fs.statSync(filepath)[options.filter]();
+        }
       } catch(e) {
         // Otherwise, it's probably not the right type.
         return false;

test/grunt/file_test.js

@@ -144,7 +144,7 @@ exports['file.expand*'] = {
     test.done();
   },
   'filter': function(test) {
-    test.expect(4);
+    test.expect(5);
     test.deepEqual(grunt.file.expand({filter: 'isFile'}, '**d*/**'), [
       'deep/deep.txt',
       'deep/deeper/deeper.txt',
@@ -155,6 +155,10 @@ exports['file.expand*'] = {
       'deep/deeper',
       'deep/deeper/deepest'
     ], 'should match directories only.');
+    test.deepEqual(grunt.file.expand({filter: function(filepath) { return (/deepest/).test(filepath); }}, '**'), [
+      'deep/deeper/deepest',
+      'deep/deeper/deepest/deepest.txt',
+    ], 'should filter arbitrarily.');
     test.deepEqual(grunt.file.expand({filter: 'isFile'}, 'js', 'css'), [], 'should fail to match.');
     test.deepEqual(grunt.file.expand({filter: 'isDirectory'}, '**/*.js'), [], 'should fail to match.');
     test.done();