Allow unset crs (#2031)

* allow unset crs
in the spirit of the comment on the above line https://github.com/geopython/pygeoapi/blob/75f87393365b17245d8dd6ba88196636f922b445/pygeoapi/provider/parquet.py#L127 , allow 'crs' to be unset and set default.

* set the correct default CRS
per the geoparquet standard

* add test for parquet file with no crs in metadata

Author: danielsparing

pygeoapi/provider/parquet.py

@@ -125,8 +125,8 @@ def __init__(self, provider_def):
             geo_metadata = json.loads(self.ds.schema.metadata[b'geo'])
             geom_column = geo_metadata['primary_column']
             # if the CRS is not set default to EPSG:4326, per geoparquet spec
-            self.crs = (geo_metadata['columns'][geom_column]['crs']
-                        or 'EPSG:4326')
+            self.crs = (geo_metadata['columns'][geom_column].get('crs')
+                        or 'OGC:CRS84')
 
     def _read_parquet(self, return_scanner=False, **kwargs):
         """

tests/data/random_nocrs.parquet

@@ -40,6 +40,9 @@
 path_nogeom = get_test_file_path(
     'data/random_nogeom.parquet')
 
+path_nocrs = get_test_file_path(
+    'data/random_nocrs.parquet')
+
 
 @pytest.fixture()
 def config_parquet():
@@ -70,6 +73,22 @@ def config_parquet_nogeom_notime():
     }
 
 
+@pytest.fixture()
+def config_parquet_nocrs():
+    return {
+        'name': 'ParquetNoCrs',
+        'type': 'feature',
+        'data': {
+            'source_type': 'Parquet',
+            'source': path_nocrs,
+        },
+        'id_field': 'id',
+        'time_field': 'time',
+        'x_field': 'lon',
+        'y_field': 'lat',
+    }
+
+
 def test_get_fields(config_parquet):
     """Testing field types"""
 
@@ -209,3 +228,13 @@ def test_query_nogeom(config_parquet_nogeom_notime):
     assert len(feature_collection.get('features')) > 0
     for feature in feature_collection['features']:
         assert feature.get('geometry') is None
+
+
+def test_query_nocrs(config_parquet_nocrs):
+    """Testing a parquet provider without CRS"""
+
+    p = ParquetProvider(config_parquet_nocrs)
+    results = p.get_fields()
+    assert results['lat']['type'] == 'number'
+    assert results['lon']['format'] == 'double'
+    assert results['time']['format'] == 'date-time'