Allow retrieving extra properties in oracle provider (#1544)

* Implement extra_properties in oracle Provider

These can be used to configure additional database-computed fields
in the config file which are returned on `get` and `query` calls

* Allow mandating properties which are not part of the output

Previously, properties which were not requested for the output
were not part of `fields`, which means that they were not passed
in to the provider as filter properties for e.g. `query()`.

This commit adds them there and introduces a new variable
`filtered_fields`, which is used for limiting the output of queries.

There is also some minor refactoring, but the existing and also the
newly written tests should avoid regressions.

* Restore previous behavior for default arguments

tests/test_oracle_provider.py

@@ -32,6 +32,7 @@
 
 import os
 import pytest
+from pygeoapi.provider.base import ProviderInvalidQueryError
 from pygeoapi.provider.oracle import OracleProvider
 
 USERNAME = os.environ.get("PYGEOAPI_ORACLE_USER", "geo_test")
@@ -202,6 +203,14 @@ def config_properties(config):
     }
 
 
+@pytest.fixture()
+def config_extra_properties(config):
+    return {
+        **config,
+        "extra_properties": ["'Here the name is ' || name || '!' as tooltip"],
+    }
+
+
 @pytest.fixture()
 def create_geojson():
     return {
@@ -332,15 +341,18 @@ def test_get_fields_properties(config_properties):
     Test get_fields with subset of columns.
     Test of property configuration.
     """
+    # NOTE: properties does not influence fields because
+    #       the fields are also used for filtering
     expected_fields = {
         "id": {"type": "NUMBER"},
         "name": {"type": "VARCHAR2"},
         "wiki_link": {"type": "VARCHAR2"},
+        "area": {"type": "NUMBER"},
+        "volume": {"type": "NUMBER"},
     }
 
     provider = OracleProvider(config_properties)
     provided_fields = provider.get_fields()
-    print(provided_fields)
 
     assert provided_fields == expected_fields
     assert provider.fields == expected_fields
@@ -356,6 +368,15 @@ def test_query_with_property_filter(config):
     assert features[0].get("id") == 12
 
 
+def test_query_with_extra_properties(config_extra_properties):
+    p = OracleProvider(config_extra_properties)
+
+    feature_collection = p.query(properties=[("name", "Aral Sea")])
+    features = feature_collection.get("features")
+
+    assert features[0]["properties"]["tooltip"] == "Here the name is Aral Sea!"
+
+
 def test_query_bbox(config):
     """Test query with a specified bounding box"""
     p = OracleProvider(config)
@@ -407,6 +428,17 @@ def test_get(config):
     assert result.get("next") == 6
 
 
+def test_get_with_extra_properties(config_extra_properties):
+    """Test simple get"""
+    p = OracleProvider(config_extra_properties)
+    result = p.get(5)
+
+    assert (
+        result["properties"]["tooltip"] ==
+        "Here the name is L. Erie!"
+    )
+
+
 def test_create(config, create_geojson):
     """Test simple create"""
     p = OracleProvider(config)
@@ -557,3 +589,30 @@ def test_create_point(config, create_point_geojson):
     data = p.get(28)
 
     assert data.get("geometry").get("type") == "Point"
+
+
+def test_query_can_mandate_properties_which_are_not_returned(config):
+    config = {
+        **config,
+        # 'name' has to be filtered, but only 'wiki_link' is returned
+        "properties": ["id", "wiki_link"],
+        "mandatory_properties": ["name"]
+    }
+
+    p = OracleProvider(config)
+    result = p.query(properties=[("name", "Aral Sea")])
+
+    (feature,) = result['features']
+    # id is handled separately, so only wiki link and not name must be here
+    assert feature['properties'].keys() == {"wiki_link"}
+
+
+def test_query_mandatory_properties_must_be_specified(config):
+    config = {
+        **config,
+        "mandatory_properties": ["name"]
+    }
+
+    p = OracleProvider(config)
+    with pytest.raises(ProviderInvalidQueryError):
+        p.query(properties=[("id", "123")])