Issue 87 - Added fs.fsync() as a no-op, and added tests. Modified docume...

src/filesystem/implementation.js

@@ -1528,6 +1528,15 @@ define(function(require) {
     unlink_node(context, path, standard_check_result_cb(callback));
   }
 
+  function fsync(fs, context, fd, callback) {
+    var ofd = fs.openFiles[fd];
+    if(!ofd) {
+      callback(new Errors.EBADF());
+    } else {
+      callback();
+    }
+  }
+
   function read(fs, context, fd, buffer, offset, length, position, callback) {
     // Follow how node.js does this
     function wrapped_cb(err, bytesRead) {
@@ -1898,6 +1907,7 @@ define(function(require) {
     stat: stat,
     fstat: fstat,
     link: link,
+    fsync: fsync,
     read: read,
     readFile: readFile,
     write: write,

src/filesystem/interface.js

@@ -222,6 +222,7 @@ define(function(require) {
     'fstat',
     'link',
     'unlink',
+    'fsync',
     'read',
     'readFile',
     'write',

tests/spec/fs.fsync.spec.js

@@ -0,0 +1,33 @@
+define(["Filer", "util"], function(Filer, util) {
+
+  describe('fs.fsync', function() {
+    beforeEach(util.setup);
+    afterEach(util.cleanup);
+
+    it('should be a function', function() {
+      var fs = util.fs();
+      expect(fs.fsync).to.be.a('function');
+    });
+
+    it('should return error when fd is invalid', function() {
+      var fs = util.fs();
+      fs.fsync(1, function(error){
+      	expect(error).to.exist;
+      });
+    });
+
+    it('should not error if the fd is valid', function(done) {
+      var fs = util.fs();
+      fs.writeFile('/myfile', 'the contents', function(error) {
+        if(error) throw error;
+        fs.open('/myfile', 'r', function(error, fd) {
+          if(error) throw error;
+          fs.fsync(fd, function(error) {
+            expect(error).to.not.exist;
+            done();
+          });
+        });
+      });
+    });
+  });
+});

tests/test-manifest.js

@@ -17,6 +17,7 @@ define([
   "spec/fs.readdir.spec",
   "spec/fs.rmdir.spec",
   "spec/fs.open.spec",
+  "spec/fs.fsync.spec",
   "spec/fs.write.spec",
   "spec/fs.writeFile-readFile.spec",
   "spec/fs.appendFile.spec",