TestCase
========

Base test case class for Slicer testing.

Test cases inherit from TestCase and implement setup, run, verify, and teardown methods.
Tests call Slicer API directly - no wrapper classes are provided.

Classes
-------

.. py:class:: Assertion

   Result of a test assertion.


.. py:class:: TestResult

   Result of running a single test case.

   **Methods:**

   .. py:method:: failed_assertions()

      Return only failed assertions.


.. py:class:: TestCaseInfo

   Information about a registered test case.


.. py:class:: TestCase
   :bases: ABC

   Base class for all test cases.
   
   Test cases implement:
   - setup(): Prepare test environment (load data, create nodes)
   - run(): Execute the test (paint, change parameters, etc.)
   - verify(): Check results with assertions
   - teardown(): Clean up (optional)
   
   Tests call Slicer functions directly. The TestContext provides only
   test-specific utilities (screenshots, timing, assertions) - not wrappers
   for Slicer API.
   
   Example:
       class TestAlgorithmWatershed(TestCase):
           name = "algorithm_watershed"
           description = "Test watershed algorithm on brain tissue"
           category = "algorithm"
   
           def setup(self, ctx: TestContext):
               import SampleData
               self.volume = SampleData.downloadSample("MRHead")
   
           def run(self, ctx: TestContext):
               ctx.screenshot("001_before", "Before painting")
               # Call Slicer/effect methods directly
               self._apply_paint()
               ctx.screenshot("002_after", "After painting")
   
           def verify(self, ctx: TestContext):
               voxel_count = self._count_voxels()
               ctx.assert_greater(voxel_count, 100, "Should segment tissue")

   **Methods:**

   .. py:method:: __init__()

      Initialize test case.

   .. py:method:: setup()

      Set up test environment.

   .. py:method:: run()

      Execute the test actions.

   .. py:method:: verify()

      Verify test results with assertions.

   .. py:method:: teardown()

      Clean up after test (optional).


Functions
---------

.. py:function:: failed_assertions()

   Return only failed assertions.

.. py:function:: setup()

   Set up test environment.
   
   Called before run(). Load sample data, create segmentation nodes,
   configure the effect. Call Slicer API directly.
   
   Args:
       ctx: Test context for screenshots, timing, assertions.

.. py:function:: run()

   Execute the test actions.
   
   Perform the main test operations: paint with the brush, change
   parameters, interact with UI. Call Slicer API directly.
   
   Args:
       ctx: Test context for screenshots, timing, assertions.

.. py:function:: verify()

   Verify test results with assertions.
   
   Check that the test produced expected results. Use ctx.assert_*
   methods to record pass/fail conditions.
   
   Args:
       ctx: Test context for screenshots, timing, assertions.

.. py:function:: teardown()

   Clean up after test (optional).
   
   Override to perform cleanup. Called after verify(), even if
   verify() raised an exception.
   
   Args:
       ctx: Test context for screenshots, timing, assertions.