Lat/lon rules

CHANGES.md

@@ -4,6 +4,8 @@
 
 - Added more rules
   - core rule "flags"
+  - core rule "lon-coordinate"
+  - core rule "lat-coordinate"
   - core rule "time-coordinate"  (#15)
   - xcube rule "time-naming"  (#15)
 

docs/rule-ref.md

@@ -30,6 +30,20 @@ Grid mappings, if any, shall have valid grid mapping coordinate variables.
 
 Contained in:  `all`-:material-lightning-bolt: `recommended`-:material-lightning-bolt:
 
+### :material-bug: `lat-coordinate`
+
+Latitude coordinate should have standard units and standard names.
+[More information.](https://cfconventions.org/cf-conventions/cf-conventions.html#latitude-coordinate)
+
+Contained in:  `all`-:material-lightning-bolt:
+
+### :material-bug: `lon-coordinate`
+
+Longitude coordinate should have standard units and standard names.
+[More information.](https://cfconventions.org/cf-conventions/cf-conventions.html#longitude-coordinate)
+
+Contained in:  `all`-:material-lightning-bolt:
+
 ### :material-lightbulb: `no-empty-attrs`
 
 Every dataset element should have metadata that describes it.

notebooks/mkdataset.py

@@ -13,10 +13,18 @@ def make_dataset() -> xr.Dataset:
         attrs=dict(title="SST-Climatology Subset"),
         coords={
             "x": xr.DataArray(
-                np.linspace(-180, 180, nx), dims="x", attrs={"units": "degrees"}
+                np.linspace(-180, 180, nx), dims="x", attrs={
+                    "standard_name": "longitude",
+                    "long_name": "longitude",
+                    "units": "degrees_east"
+                }
             ),
             "y": xr.DataArray(
-                np.linspace(-90, 90, ny), dims="y", attrs={"units": "degrees"}
+                np.linspace(-90, 90, ny), dims="y", attrs={
+                    "standard_name": "latitude",
+                    "long_name": "latitude",
+                    "units": "degrees_north"
+                }
             ),
             "time": xr.DataArray(
                 [365 * i for i in range(nt)],
@@ -55,6 +63,10 @@ def make_dataset() -> xr.Dataset:
 def make_dataset_with_issues() -> xr.Dataset:
     """Create a dataset that produces issues with xrlint core rules."""
     invalid_ds = make_dataset()
+    invalid_ds.x.attrs["units"] = "degrees"
+    invalid_ds.x.attrs["axis"] = "x"
+    del invalid_ds.y.attrs["standard_name"]
+    invalid_ds.y.attrs["axis"] = "y"
     invalid_ds.time.attrs["units"] = "days since 2020-01-01 ß0:000:00"
     invalid_ds.attrs = {}
     invalid_ds.sst.attrs["units"] = 1

tests/plugins/core/rules/test_lat_lon_coordinate.py

@@ -0,0 +1,111 @@
+import numpy as np
+import xarray as xr
+
+from xrlint.plugins.core.rules.lat_lon_coordinate import LatCoordinate
+from xrlint.plugins.core.rules.lat_lon_coordinate import LonCoordinate
+from xrlint.testing import RuleTest
+from xrlint.testing import RuleTester
+
+valid_dataset_0 = xr.Dataset()
+valid_dataset_1 = xr.Dataset(
+    coords={
+        "lat": xr.DataArray(
+            np.array([3, 4, 5]),
+            dims="lat",
+            attrs={
+                "units": "degrees_north",
+                "standard_name": "latitude",
+                "long_name": "latitude",
+            },
+        ),
+        "lon": xr.DataArray(
+            np.array([-2, -1, 0, 1]),
+            dims="lon",
+            attrs={
+                "units": "degrees_east",
+                "standard_name": "longitude",
+                "long_name": "longitude",
+            },
+        ),
+    },
+    data_vars={
+        "mask": xr.DataArray(
+            [[10, 20, 30, 40], [30, 40, 50, 60], [50, 60, 70, 80]], dims=("lat", "lon")
+        )
+    },
+)
+
+# Valid, because the coord names doesn't matter as long their metadata is ok
+valid_dataset_2 = valid_dataset_1.rename_vars({"lon": "x", "lat": "y"})
+
+# Valid, because the coord units have aliases
+valid_dataset_3 = valid_dataset_1.copy()
+valid_dataset_3.lat.attrs["units"] = "degreeN"
+valid_dataset_3.lon.attrs["units"] = "degreeE"
+
+# Valid, because the coord units have aliases
+valid_dataset_4 = valid_dataset_1.copy()
+del valid_dataset_4.lat.attrs["standard_name"]
+del valid_dataset_4.lon.attrs["standard_name"]
+valid_dataset_4.lat.attrs["axis"] = "Y"
+valid_dataset_4.lon.attrs["axis"] = "X"
+
+invalid_lat_dataset_0 = valid_dataset_1.copy()
+del invalid_lat_dataset_0.lat.attrs["standard_name"]
+
+invalid_lon_dataset_0 = valid_dataset_1.copy()
+del invalid_lon_dataset_0.lon.attrs["units"]
+
+invalid_lat_dataset_1 = valid_dataset_1.copy()
+invalid_lat_dataset_1.lat.attrs["units"] = "deg"
+
+invalid_lon_dataset_1 = valid_dataset_1.copy()
+invalid_lon_dataset_1.lon.attrs["long_name"] = "poo"
+
+invalid_lat_dataset_2 = valid_dataset_1.copy()
+del invalid_lat_dataset_2.lat.attrs["standard_name"]
+invalid_lat_dataset_2.lat.attrs["axis"] = "y"  # should be "Y"
+
+invalid_lon_dataset_2 = valid_dataset_1.copy()
+del invalid_lon_dataset_2.lon.attrs["standard_name"]
+invalid_lon_dataset_2.lon.attrs["axis"] = "x"  # should be "X"
+
+LatCoordsTest = RuleTester.define_test(
+    "lat-coordinate",
+    LatCoordinate,
+    valid=[
+        RuleTest(dataset=valid_dataset_0),
+        RuleTest(dataset=valid_dataset_1),
+        RuleTest(dataset=valid_dataset_2),
+        RuleTest(dataset=valid_dataset_3),
+        RuleTest(dataset=valid_dataset_4),
+        RuleTest(dataset=invalid_lon_dataset_0),
+        RuleTest(dataset=invalid_lon_dataset_1),
+        RuleTest(dataset=invalid_lon_dataset_2),
+    ],
+    invalid=[
+        RuleTest(dataset=invalid_lat_dataset_0),
+        RuleTest(dataset=invalid_lat_dataset_1),
+        RuleTest(dataset=invalid_lat_dataset_2),
+    ],
+)
+
+LonCoordsTest = RuleTester.define_test(
+    "lon-coordinate",
+    LonCoordinate,
+    valid=[
+        RuleTest(dataset=valid_dataset_0),
+        RuleTest(dataset=valid_dataset_1),
+        RuleTest(dataset=valid_dataset_2),
+        RuleTest(dataset=valid_dataset_3),
+        RuleTest(dataset=valid_dataset_4),
+        RuleTest(dataset=invalid_lat_dataset_0),
+        RuleTest(dataset=invalid_lat_dataset_1),
+        RuleTest(dataset=invalid_lat_dataset_2),
+    ],
+    invalid=[
+        RuleTest(dataset=invalid_lon_dataset_0),
+        RuleTest(dataset=invalid_lon_dataset_1),
+        RuleTest(dataset=invalid_lon_dataset_2),
+    ],
+)

tests/plugins/core/test_plugin.py

@@ -4,27 +4,38 @@
 
 
 class ExportPluginTest(TestCase):
-    def test_configs_complete(self):
-        _plugin = export_plugin()
-        self.assertEqual(
-            {
-                "all",
-                "recommended",
-            },
-            set(_plugin.configs.keys()),
-        )
-
     def test_rules_complete(self):
-        _plugin = export_plugin()
+        plugin = export_plugin()
         self.assertEqual(
             {
                 "coords-for-dims",
                 "dataset-title-attr",
-                "grid-mappings",
                 "flags",
+                "grid-mappings",
+                "lat-coordinate",
+                "lon-coordinate",
                 "no-empty-attrs",
                 "time-coordinate",
                 "var-units-attr",
             },
-            set(_plugin.rules.keys()),
+            set(plugin.rules.keys()),
+        )
+
+    def test_configs_complete(self):
+        plugin = export_plugin()
+        self.assertEqual(
+            {
+                "all",
+                "recommended",
+            },
+            set(plugin.configs.keys()),
+        )
+        all_rule_names = set(plugin.rules.keys())
+        self.assertEqual(
+            all_rule_names,
+            set(plugin.configs["all"].rules.keys()),
+        )
+        self.assertEqual(
+            all_rule_names,
+            set(plugin.configs["recommended"].rules.keys()),
         )

tests/plugins/xcube/test_plugin.py

@@ -4,18 +4,9 @@
 
 
 class ExportPluginTest(TestCase):
-    def test_configs_complete(self):
-        _plugin = export_plugin()
-        self.assertEqual(
-            {
-                "all",
-                "recommended",
-            },
-            set(_plugin.configs.keys()),
-        )
 
     def test_rules_complete(self):
-        _plugin = export_plugin()
+        plugin = export_plugin()
         self.assertEqual(
             {
                 "any-spatial-data-var",
@@ -27,5 +18,24 @@ def test_rules_complete(self):
                 "single-grid-mapping",
                 "time-naming",
             },
-            set(_plugin.rules.keys()),
+            set(plugin.rules.keys()),
+        )
+
+    def test_configs_complete(self):
+        plugin = export_plugin()
+        self.assertEqual(
+            {
+                "all",
+                "recommended",
+            },
+            set(plugin.configs.keys()),
+        )
+        all_rule_names = set(f"xcube/{k}" for k in plugin.rules.keys())
+        self.assertEqual(
+            all_rule_names,
+            set(plugin.configs["all"].rules.keys()),
+        )
+        self.assertEqual(
+            all_rule_names,
+            set(plugin.configs["recommended"].rules.keys()),
         )

xrlint/plugins/core/__init__.py

@@ -14,7 +14,10 @@ def export_plugin() -> Plugin:
             "rules": {
                 "coords-for-dims": "error",
                 "dataset-title-attr": "warn",
+                "flags": "error",
                 "grid-mappings": "error",
+                "lat-coordinate": "error",
+                "lon-coordinate": "error",
                 "no-empty-attrs": "warn",
                 "time-coordinate": "error",
                 "var-units-attr": "warn",