Refactor and add unit tests

Move code that confirms obs file existence or creates symlink to fcst file to
a function so that it can be tested, and the rest of the module test suite can
run without access to the `ssh dir` path.

nowcast/workers/make_ssh_files.py

@@ -180,21 +180,7 @@ def make_ssh_file(parsed_args, config, *args):
         else:
             checklist[run_type].update({"obs": filepath})
 
-    # Confirm that obs files were created. If not, create them by symlinking to fcst file for date
-    earliest_obs_date = (
-        run_date.shift(days=-4) if run_type == "nowcast" else run_date.shift(days=-5)
-    )
-    obs_dates = arrow.Arrow.range("days", earliest_obs_date, run_date.shift(days=-1))
-    for obs_date in obs_dates:
-        obs_file = config["ssh"]["file template"].format(obs_date.datetime)
-        obs_path = ssh_dir / "obs" / obs_file
-        if not obs_path.exists():
-            fcst_relative_path = Path("..", "fcst", obs_file)
-            obs_path.symlink_to(fcst_relative_path)
-            logger.critical(
-                f"{obs_path} was not created; using {fcst_relative_path} instead via symlink"
-            )
-            checklist[run_type].update({"obs": os.fspath(fcst_relative_path)})
+    _ensure_all_files_created(run_date, run_type, ssh_dir, checklist, config)
 
     if parsed_args.text_file is None:
         _render_plot(fig, ax, config)
@@ -371,6 +357,24 @@ def _save_netcdf(day, tc, surges, forecast_flag, textfile, config, lats, lons):
     return filepath
 
 
+def _ensure_all_files_created(run_date, run_type, ssh_dir, checklist, config):
+    """Confirm that obs files were created. If not, create them by symlinking to fcst file for date."""
+    earliest_obs_date = (
+        run_date.shift(days=-4) if run_type == "nowcast" else run_date.shift(days=-5)
+    )
+    obs_dates = arrow.Arrow.range("days", earliest_obs_date, run_date.shift(days=-1))
+    for obs_date in obs_dates:
+        obs_file = config["ssh"]["file template"].format(obs_date.datetime)
+        obs_path = ssh_dir / "obs" / obs_file
+        if not obs_path.exists():
+            fcst_relative_path = Path("..", "fcst", obs_file)
+            obs_path.symlink_to(fcst_relative_path)
+            logger.critical(
+                f"{obs_path} was not created; using {fcst_relative_path} instead via symlink"
+            )
+            checklist[run_type].update({"obs": os.fspath(fcst_relative_path)})
+
+
 def _setup_plot():
     fig = matplotlib.figure.Figure(figsize=(10, 4))
     ax = fig.add_subplot(1, 1, 1)

tests/workers/test_make_ssh_file.py

@@ -231,6 +231,15 @@ def mock_get_lons_lats(config):
 
         monkeypatch.setattr(make_ssh_files, "_get_lons_lats", mock_get_lons_lats)
 
+        def mock_ensure_all_files_created(
+            run_date, run_type, ssh_dir, checklist, config
+        ):
+            pass
+
+        monkeypatch.setattr(
+            make_ssh_files, "_ensure_all_files_created", mock_ensure_all_files_created
+        )
+
         def mock_render_plot(fig, ax, config):
             pass
 
@@ -252,3 +261,48 @@ def mock_render_plot(fig, ax, config):
         csv_file = Path(f"etss.{yyyymmdd}.t{forecast}z.csv")
         expected = {run_type: {"csv": os.fspath(ssh_dir / "txt" / csv_file)}}
         assert checklist == expected
+
+
+@pytest.mark.parametrize(
+    "run_type, run_date",
+    (
+        ("nowcast", arrow.get("2022-10-18")),
+        ("forecast2", arrow.get("2022-10-18")),
+    ),
+)
+class TestMakeSshFile:
+    """Unit tests for _ensure_all_files_created() function."""
+
+    def test_ensure_all_files_created(
+        self, run_type, run_date, config, caplog, tmp_path
+    ):
+        ssh_dir = tmp_path / "sshNeahBay"
+        ssh_dir.mkdir()
+        (ssh_dir / "obs").mkdir()
+        (ssh_dir / "fcst").mkdir()
+        obs_filename_tmpl = "ssh_{:y%Ym%md%d}.nc"
+        earliest_obs_date = (
+            run_date.shift(days=-4)
+            if run_type == "nowcast"
+            else run_date.shift(days=-5)
+        )
+        obs_dates = arrow.Arrow.range(
+            "days", earliest_obs_date, run_date.shift(days=-2)
+        )
+        for obs_date in obs_dates:
+            (ssh_dir / "obs" / obs_filename_tmpl.format(obs_date.datetime)).touch()
+        checklist = {run_type: {}}
+        caplog.set_level(logging.DEBUG)
+
+        make_ssh_files._ensure_all_files_created(
+            run_date, run_type, ssh_dir, checklist, config
+        )
+
+        expected_filename = obs_filename_tmpl.format(run_date.shift(days=-1).datetime)
+        expected_path = ssh_dir / "obs" / expected_filename
+        assert expected_path.is_symlink()
+        assert expected_path.resolve() == ssh_dir / "fcst" / expected_filename
+        assert caplog.records[0].levelname == "CRITICAL"
+        expected = f"{expected_path} was not created; using ../fcst/{expected_filename} instead via symlink"
+        assert caplog.messages[0] == expected
+        assert checklist[run_type]["obs"] == f"../fcst/{expected_filename}"