Add test for fsPromises.rmdir() when dir not empty and dir is a file, Fix Issue 474 (#510)

* Saving files before refreshing line endings

* Adding test case for returning an error if the path is not a directory

* Add return for fsPromises, and few other small fixes

* Fix promises, and few done parameter

* Update fs.rmdir.spec.js

tests/spec/fs.rmdir.spec.js

@@ -121,3 +121,34 @@ describe('fs.rmdir', function() {
       });
   });
 });
+
+describe('fs.promises.rmdir', function(){
+  beforeEach(util.setup);
+  afterEach(util.cleanup);
+
+  it('should return an error if the directory is not empty', function() {
+    var fs = util.fs();
+    var fsPromises = fs.promises;
+
+    return fsPromises.mkdir('/tmp')
+      .then(() => fsPromises.mkdir('/tmp/mydir'))
+      .then(() => fsPromises.rmdir('/'))
+      .catch(error => {
+        expect(error).to.exist;
+        expect(error.code).to.equal('EBUSY');
+      });
+  });
+ 
+  it('should return an error if the path is not a directory', function() {
+    var fs = util.fs();
+    var fsPromises = fs.promises;
+
+    return fsPromises.mkdir('/tmp')
+      .then(() => fsPromises.writeFile('/tmp/myfile','Hello World'))
+      .then(() => fsPromises.rmdir('/tmp/myfile'))
+      .catch(error => {
+        expect(error).to.exist;
+        expect(error.code).to.equal('ENOTDIR');
+      });
+  });
+});