Add an output method for the chgres_cube driver (#674)

* Add output method

* Update src/uwtools/drivers/chgres_cube.py

Use lowercase key

Co-authored-by: Paul Madden <136389411+maddenp-noaa@users.noreply.github.com>

* Change key to lowercase

---------

Co-authored-by: Paul Madden <136389411+maddenp-noaa@users.noreply.github.com>

src/uwtools/drivers/chgres_cube.py

@@ -110,5 +110,14 @@ def driver_name(cls) -> str:
         """
         return STR.chgrescube
 
+    @property
+    def output(self) -> dict[str, list[str]]:
+        """
+        Returns a description of the file(s) created when this component runs.
+        """
+        output_types = ["atm", "sfc"]
+        paths = [f"{self.rundir}/out.{t}.tile7.nc" for t in output_types]
+        return {"netcdffiles": paths}
+
 
 set_driver_docstring(ChgresCube)

src/uwtools/tests/drivers/test_chgres_cube.py

@@ -10,11 +10,10 @@
 
 import f90nml  # type: ignore
 from iotaa import refs
-from pytest import fixture, mark, raises
+from pytest import fixture, mark
 
 from uwtools.drivers.chgres_cube import ChgresCube
 from uwtools.drivers.driver import Driver
-from uwtools.exceptions import UWNotImplementedError
 from uwtools.logging import log
 from uwtools.scheduler import Slurm
 from uwtools.tests.support import logged, regex_logged
@@ -107,7 +106,6 @@ def leadtime():
         "_scheduler",
         "_validate",
         "_write_runscript",
-        "output",
         "run",
     ],
 )
@@ -150,9 +148,9 @@ def test_ChgresCube_namelist_file_missing_base_file(caplog, driverobj):
 
 
 def test_ChgresCube_output(driverobj):
-    with raises(UWNotImplementedError) as e:
-        assert driverobj.output
-    assert str(e.value) == "The output() method is not yet implemented for this driver"
+    files = ["out.atm.tile7.nc", "out.sfc.tile7.nc"]
+    expected = {"netcdffiles": [str(driverobj.rundir / file) for file in files]}
+    assert driverobj.output == expected
 
 
 def test_ChgresCube_provisioned_rundir(driverobj):