.NET builder tasks in Bamboo (e.g. NAnt) do not parse test information as part of the task. You must configure a test task (e.g. MSTest Parser), if you want test results from the builder task to be parsed.
To configure a MSTest Parser executable for a task:
Navigate to the task configuration for the job (this will be the default job if creating a new plan).
Click the name of the desired MSTest Parser task, or click Add Task and then MSTest Parser if creating a new task.
Update the task settings:
Task Description — Enter a description of the task, for display in Bamboo.
MBUnit Test Results File — Enter the name of the test results file. The test file must be in MSTest format. For more information on MSTest, see this MSDN page.