Why put parentheses on TestMethod attribute in UnitTest

Question

In lots of tutorials for UnitTesting, the way to mark a TestMethod was different. I saw these options:

[TestMethod] 
[TestMethod()]

What is the difference?

Answer 1

With and without brackets its exactly the same:

[TestMethod] 
[TestMethod()]

The empty brackets just call the default constructor of that attribute that has no parameters. So does [TestMethod]. Both call the default constructor.

This would be different:

[TestMethod(SomeParameter)]

And [Test] is an attribute that comes from NUnit library and is different from the .Net [TestMethod] attribute.

Answer 2

The empty parentheses are redundant, the two lines are equivalent. Tools such as ReSharper would give you the option of removing this redundancy from your code.

Answer 3

[TestMethod] 
[TestMethod()]

Both are same but when Visual Studio auto generate test method it comes with [TestMethod()]