test: parametrize two clean duplicated-test clusters

tests/waterdata_test.py

@@ -1024,21 +1024,20 @@ def test_string_returned_unchanged(self):
         # Note: no hyphen requirement here — that's monitoring_location_id-specific.
         assert _normalize_str_iterable("dog", "parameter_code") == "dog"
 
-    def test_list_returned_unchanged(self):
-        assert _normalize_str_iterable(["00060", "00010"], "p") == ["00060", "00010"]
-
-    def test_tuple_normalizes_to_list(self):
-        result = _normalize_str_iterable(("00060", "00010"), "p")
-        assert result == ["00060", "00010"]
-        assert isinstance(result, list)
-
-    def test_pandas_series_normalizes_to_list(self):
-        result = _normalize_str_iterable(pd.Series(["00060", "00010"]), "p")
-        assert result == ["00060", "00010"]
-        assert isinstance(result, list)
-
-    def test_numpy_array_normalizes_to_list(self):
-        result = _normalize_str_iterable(np.array(["00060", "00010"]), "p")
+    @pytest.mark.parametrize(
+        "value",
+        [
+            ["00060", "00010"],
+            ("00060", "00010"),
+            pd.Series(["00060", "00010"]),
+            np.array(["00060", "00010"]),
+        ],
+        ids=["list", "tuple", "series", "ndarray"],
+    )
+    def test_iterable_normalizes_to_list(self, value):
+        """Any iterable of strings (list / tuple / Series / ndarray) comes back
+        as a plain ``list``."""
+        result = _normalize_str_iterable(value, "p")
         assert result == ["00060", "00010"]
         assert isinstance(result, list)
 

tests/waterdata_utils_test.py

@@ -671,64 +671,49 @@ def test_arrange_cols_keeps_geometry_when_present():
 # --- _format_api_dates -------------------------------------------------------
 
 
-def test_format_api_dates_iso8601_with_z():
-    """ISO 8601 datetimes with a 'Z' suffix must be parsed, not dropped to None."""
-    assert _format_api_dates("2018-02-12T23:20:50Z") == "2018-02-12T23:20:50Z"
-
-
-def test_format_api_dates_iso8601_with_fractional_seconds():
-    assert _format_api_dates("2018-02-12T23:20:50.123Z") == "2018-02-12T23:20:50Z"
-
-
-def test_format_api_dates_iso8601_with_offset():
-    """Numeric offsets must be converted to UTC."""
-    assert _format_api_dates("2018-02-12T19:20:50-04:00") == "2018-02-12T23:20:50Z"
-
-
-def test_format_api_dates_iso8601_pair():
-    """A list of two ISO 8601 datetimes must be parsed into a UTC interval."""
-    result = _format_api_dates(["2018-02-12T23:20:50Z", "2018-03-18T12:31:12Z"])
-    assert result == "2018-02-12T23:20:50Z/2018-03-18T12:31:12Z"
-
-
-def test_format_api_dates_passthrough_interval():
-    assert _format_api_dates("2018-02-12T00:00:00Z/..") == "2018-02-12T00:00:00Z/.."
-
-
-def test_format_api_dates_passthrough_duration():
-    assert _format_api_dates("P7D") == "P7D"
-
-
-def test_format_api_dates_passthrough_time_only_duration():
-    """ISO 8601 time-only durations (PT...) are passed through unchanged."""
-    assert _format_api_dates("PT36H") == "PT36H"
-
-
-def test_format_api_dates_word_with_p_is_not_a_duration():
-    """Strings containing the letter 'p' must not be misclassified as durations."""
-    assert _format_api_dates("Apr") is None
-
-
-def test_format_api_dates_date_only():
-    assert _format_api_dates("2024-01-01", date=True) == "2024-01-01"
-
-
-def test_format_api_dates_date_only_pair():
-    assert (
-        _format_api_dates(["2024-01-01", "2024-02-01"], date=True)
-        == "2024-01-01/2024-02-01"
-    )
-
-
-def test_format_api_dates_space_separated_still_works():
-    """The legacy space-separated format must still parse."""
-    assert _format_api_dates("2024-01-01 00:00:00", date=True) == "2024-01-01"
-
-
-def test_format_api_dates_open_ended_range_with_none():
-    """A None / NaN endpoint becomes '..' in the output range."""
-    assert _format_api_dates(["2024-01-01", None], date=True) == "2024-01-01/.."
-    assert _format_api_dates([None, "2024-01-01"], date=True) == "../2024-01-01"
+@pytest.mark.parametrize(
+    "value, date, expected",
+    [
+        ("2018-02-12T23:20:50Z", False, "2018-02-12T23:20:50Z"),
+        ("2018-02-12T23:20:50.123Z", False, "2018-02-12T23:20:50Z"),
+        ("2018-02-12T19:20:50-04:00", False, "2018-02-12T23:20:50Z"),
+        (
+            ["2018-02-12T23:20:50Z", "2018-03-18T12:31:12Z"],
+            False,
+            "2018-02-12T23:20:50Z/2018-03-18T12:31:12Z",
+        ),
+        ("2018-02-12T00:00:00Z/..", False, "2018-02-12T00:00:00Z/.."),
+        ("P7D", False, "P7D"),
+        ("PT36H", False, "PT36H"),
+        ("Apr", False, None),
+        ("2024-01-01", True, "2024-01-01"),
+        (["2024-01-01", "2024-02-01"], True, "2024-01-01/2024-02-01"),
+        ("2024-01-01 00:00:00", True, "2024-01-01"),
+        (["2024-01-01", None], True, "2024-01-01/.."),
+        ([None, "2024-01-01"], True, "../2024-01-01"),
+    ],
+    ids=[
+        "iso8601_z",
+        "fractional_seconds",
+        "offset_to_utc",
+        "iso8601_pair_to_interval",
+        "passthrough_interval",
+        "passthrough_duration",
+        "time_only_duration",
+        "word_with_p_not_duration",
+        "date_only",
+        "date_only_pair",
+        "space_separated",
+        "open_ended_none_end",
+        "open_ended_none_start",
+    ],
+)
+def test_format_api_dates(value, date, expected):
+    """``_format_api_dates`` normalizes ISO 8601 datetimes to UTC (dropping
+    fractional seconds, converting offsets), joins a pair into an interval,
+    passes durations / intervals through unchanged, renders a None endpoint as
+    ``..``, and returns None for a non-date word (e.g. ``"Apr"``)."""
+    assert _format_api_dates(value, date=date) == expected
 
 
 def test_format_api_dates_rejects_mapping():