Add credentials checking

* gn3/auth/authentication.py: new function `credentials_in_database`
* gn3/auth/authentication/__init__.py: replace package with module
* gn3/settings.py: new `AUTH_MIGRATIONS` configuration variable
* migrations/auth/20221103_02_sGrIs-create-user-credentials-table.py: new
  migration
* tests/unit/auth/test_credentials.py: test the `credentials_in_database`
  function
* tests/unit/conftest.py: more test fixtures

1 files changed, 21 insertions, 0 deletions

diff --git a/tests/unit/auth/test_credentials.py b/tests/unit/auth/test_credentials.py
new file mode 100644
index 0000000..fbfd303
--- /dev/null
+++ b/tests/unit/auth/test_credentials.py
@@ -0,0 +1,21 @@
+"""Test the credentials checks"""
+import sqlite3
+
+import pytest
+from contextlib import closing
+from hypothesis import given, settings, strategies, HealthCheck
+
+from gn3.auth.authentication import credentials_in_database
+
+@pytest.mark.unit_test
+@given(strategies.emails(), strategies.text())
+@settings(suppress_health_check=[HealthCheck.function_scoped_fixture])
+def test_credentials_not_in_database(conn_after_auth_migrations, email, password):
+    """
+    GIVEN: credentials that do not exist in the database
+    WHEN: the `credentials_in_database` function is run against the credentials
+    THEN: check that the function returns false in all cases.
+    """
+    with closing(conn_after_auth_migrations.cursor()) as cursor:
+        results = credentials_in_database(cursor, email, password)
+        assert credentials_in_database(cursor, email, password) is False