Add test for new donutQualityTable behavior.

python/lsst/ts/wep/task/calcZernikesTask.py

@@ -349,7 +349,20 @@ def createZkTable(
     def empty(self, qualityTable=None) -> pipeBase.Struct:
         """Return empty results if no donuts are available. If
         it is a result of no quality donuts we still include the
-        quality table results instead of an empty quality table."""
+        quality table results instead of an empty quality table.
+
+        Parameters
+        ----------
+        qualityTable : astropy.table.QTable
+            Quality table created with donut stamp input.
+
+        Returns
+        -------
+        lsst.pipe.base.Struct
+            Empty output tables for zernikes. Empty quality table
+            if no donuts. Otherwise contains quality table
+            with donuts that all failed to pass quality check.
+        """
         qualityTableCols = [
             "SN",
             "ENTROPY",

tests/task/test_calcZernikesTieTaskScienceSensor.py

@@ -225,6 +225,13 @@ def testCalcZernikes(self):
             self.assertIsInstance(struct.outputZernikesRaw, np.ndarray)
             self.assertIsInstance(struct.outputZernikesAvg, np.ndarray)
             self.assertIsInstance(struct.zernikes, QTable)
+        self.assertEqual(len(structNormal.donutQualityTable), 6)
+        self.assertEqual(len(structNull.donutQualityTable), 0)
+
+        self.config.donutStampSelector.maxSelect = 0
+        self.task = CalcZernikesTask(config=self.config)
+        structAllDonutsFail = self.task.run(donutStampsIntra, donutStampsExtra)
+        self.assertEqual(len(structAllDonutsFail.donutQualityTable), 6)
 
     def testGetCombinedZernikes(self):
         testArr = np.zeros((2, 19))