#223: Add tests for DatabaseFilterUtilities

test/db/test_database_filter_utilities.py

@@ -0,0 +1,104 @@
+import pytest
+
+from datagateway_api.common.database.filters import DatabaseFilterUtilities
+from datagateway_api.common.database.helpers import ReadQuery
+from datagateway_api.common.exceptions import FilterError
+from datagateway_api.common.helpers import get_entity_object_from_name
+
+
+class TestDatabaseFilterUtilities:
+    @pytest.mark.parametrize(
+        "input_field, expected_fields",
+        [
+            pytest.param("name", ("name", None, None), id="Unrelated field"),
+            pytest.param(
+                "facility.daysUntilRelease",
+                ("facility", "daysUntilRelease", None),
+                id="Related field matching ICAT schema name",
+            ),
+            pytest.param(
+                "FACILITY.daysUntilRelease",
+                ("FACILITY", "daysUntilRelease", None),
+                id="Related field matching database format (uppercase)",
+            ),
+            pytest.param(
+                "user.investigationUsers.role",
+                ("user", "investigationUsers", "role"),
+                id="Related related field (2 levels deep)",
+            ),
+        ],
+    )
+    def test_valid_extract_filter_fields(self, input_field, expected_fields):
+        test_utility = DatabaseFilterUtilities()
+        test_utility._extract_filter_fields(input_field)
+
+        assert test_utility.field == expected_fields[0]
+        assert test_utility.related_field == expected_fields[1]
+        assert test_utility.related_related_field == expected_fields[2]
+
+    def test_invalid_extract_filter_fields(self):
+        test_utility = DatabaseFilterUtilities()
+
+        with pytest.raises(ValueError):
+            test_utility._extract_filter_fields(
+                "user.investigationUsers.investigation.summary",
+            )
+
+    @pytest.mark.parametrize(
+        "input_field",
+        [
+            pytest.param("name", id="No related fields"),
+            pytest.param("facility.daysUntilRelease", id="Related field"),
+            pytest.param(
+                "investigationUsers.user.fullName", id="Related related field",
+            ),
+        ],
+    )
+    def test_valid_add_query_join(
+        self, flask_test_app_db, input_field,
+    ):
+        table = get_entity_object_from_name("Investigation")
+
+        test_utility = DatabaseFilterUtilities()
+        test_utility._extract_filter_fields(input_field)
+
+        expected_query = ReadQuery(table)
+        if test_utility.related_related_field:
+            expected_table = get_entity_object_from_name(test_utility.related_field)
+
+            included_table = get_entity_object_from_name(test_utility.field)
+            expected_query.base_query = expected_query.base_query.join(
+                included_table,
+            ).join(expected_table)
+        elif test_utility.related_field:
+            expected_table = get_entity_object_from_name(test_utility.field)
+
+            expected_query = ReadQuery(table)
+            expected_query.base_query = expected_query.base_query.join(expected_table)
+        else:
+            expected_table = table
+
+        with ReadQuery(table) as test_query:
+            output_field = test_utility._add_query_join(test_query)
+
+        # Check the JOIN has been applied
+        assert str(test_query.base_query) == str(expected_query.base_query)
+
+        # Check the output is correct
+        field_name_to_fetch = input_field.split(".")[-1]
+        assert output_field == getattr(expected_table, field_name_to_fetch)
+
+    def test_valid_get_field(self, flask_test_app_db):
+        table = get_entity_object_from_name("Investigation")
+
+        test_utility = DatabaseFilterUtilities()
+        field = test_utility._get_field(table, "name")
+
+        assert field == table.name
+
+    def test_invalid_get_field(self, flask_test_app_db):
+        table = get_entity_object_from_name("Investigation")
+
+        test_utility = DatabaseFilterUtilities()
+        with pytest.raises(FilterError):
+            test_utility._get_field(table, "unknown")