As a cross-platform test runner, NCrunch is able to identify the categories of tests as defined by the framework they are expressed in. These categories can be very useful when controlling the behaviour of the continuous test runner through custom engine modes.
Identification of categories is mostly specific to the individual test frameworks. As not all frameworks support categorisation of tests at both fixture and method level, NCrunch introduces a custom attribute, NCrunch.Framework.Category, which can be used to apply categories at both fixture and method level for any test framework.
Category identification for supported test frameworks is as follows:
NCrunch will respect any declaration of NUnit's 'Category' attribute, along with any rules around inheritance and context. NUnit's Category attribute is just as powerful as NCrunch.Framework.Category and as such there is no need to use NCrunch.Framework.Category.
NCrunch makes use of MbUnit's Category attribute in the same manner as NCrunch.Framework.Category and it can be applied at both fixture and method level. As such, NCrunch.Framework.Category is not necessary for MbUnit.
NCrunch recognises MSTest's TestCategory attribute at method level.
NCrunch also makes use of MSTest's 'TestProperty' attribute in order to establish categories.
As a test property has both a name and a value, NCrunch will put both of these together to form the category of the test. For example, the attribute 'TestProperty("MyName", "MyValue")' will place the test under the category 'MyName=MyValue'.
Where the name of the property is 'Category', NCrunch will use only the value of the property to form the category. For example, the attribute 'TestProperty("Category", "MyCategory")' will place the test under the category 'MyCategory'.
MSTest's TestProperty and TestCategory attributes cannot be applied at fixture level, so fixture level categories can only be declared using NCrunch.Framework.Category.
NCrunch makes use of Xunit's 'Trait' attribute in order to establish categories.
As the trait attribute has both a name and a value, NCrunch will apply the same categorisation rules to this attribute as is applied to MSTest's TestProperty attribute (above).
Because the trait attribute can be applied at both fixture level and method level, there is no need to make use of NCrunch.Framework.Category.
NCrunch makes use of MSpec's 'Tags' attribute in order to establish categories.
The 'Tags' attribute can only be applied at fixture level, so categorisation at specification level is only possible through the use of NCrunch.Framework.Category. However, it is worth noting that the runtime behaviour of MSpec requires all specifications for a context/fixture to be run together, so trying to categorise specifications separately may not be very useful.