Organizing Test Cases
In addition to the TestInitialize and TestMethod attributes that you're used to using when creating automated tests, there's also a TestCategory attribute that you'll find useful as the number of your tests starts to get overwhelming.
Effectively, using TestCategory lets you create a group of tests using any arbitrary system you want. This allows you to create (and run!) groups of tests that you feel are related without having to run every test in a class, a project or a solution. These could be, for examples, all the tests in all your test classes that involve your Customer factory or all the tests that use your repository class.
To use TestCategory, you add it as a separate attribute to a test or combine it with your already existing test attributes. These two sets of code are identical, for example, and assign GetAllTest to the Data category:
[TestMethod, TestCategory("Data")]
public void GetAllTest()
[TestMethod]
[TestCategory("Data")]
public void GetAllTest()
You can also assign a test to multiple categories. These examples tie the GetAllTest test to both the Data and the Customers categories:
[TestMethod, TestCategory("Data"), TestCategory("Customers")]
public void GetAllTest()
[TestMethod]
[TestCategory("Data")]
[TestCategory("Customers")]
public void GetAllTest()
You can run tests in any particular category from Test Explorer. First, though, you must make sure that your tests are in List view: If your Tests are grouped in any way other than Run | Not Run | Failed, then you're not in List view (List view still groups your tests, it just does it in the default grouping of "by result"). The toggle that switches between List and Hierarchical view is the second button in on the Test Explorer toolbar, just to the right of the Run Tests After Build toggle.
Once you're in List view, the Group By toggle (just to the right of the List View toggle) will be enabled. Click the down arrow on the right side of the Goup By toggle and you'll get a list all of the ways you can group your tests. To group by category, you want to pick Traits from this list. Not only will this list all the tests you've assigned to a category, it will list any test to which you haven't assigned a category in a group called No Traits. Right-clicking on a category name will let you run all the tests in that category.
You can also run tests by category using the VsTest.Console or MSTest command-line tools. Those tools also give you an additional ability: You can combine categories with logical operators to either run only those tests that appear in the intersection of the categories you list or run all the tests from all of the categories you list.
Posted by Peter Vogel on 08/01/2018