Set up testing with pytest and co

tests/conftest.py

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+import logging
+
+import pytest
+import sqlparse
+from sqlalchemy import create_engine, event
+from sqlalchemy.exc import OperationalError
+from sqlalchemy.orm import Session
+
+from dibbler.models import Base
+
+
+def pytest_addoption(parser):
+    parser.addoption(
+        "--debug-sql",
+        action="store_true",
+        help="Enable SQLAlchemy 'echo' mode for debugging",
+    )
+
+
+class SqlParseFormatter(logging.Formatter):
+    def format(self, record):
+        recordMessage = record.getMessage()
+        if not recordMessage.startswith("[") and any(
+            recordMessage.startswith(keyword)
+            for keyword in [
+                "SELECT",
+                "INSERT",
+                "UPDATE",
+                "DELETE",
+                "WITH",
+            ]
+        ):
+            formatted_sql = sqlparse.format(recordMessage, reindent=True, keyword_case="upper")
+            record.msg = "\n" + formatted_sql
+
+        return super().format(record)
+
+
+def pytest_configure(config):
+    """Setup pretty SQL logging if --debug-sql is enabled."""
+
+    logger = logging.getLogger("sqlalchemy.engine")
+
+    # TODO: it would be nice not to duplicate these logs.
+    #       logging.NullHandler() does not seem to work here
+    handler = logging.StreamHandler()
+    handler.setFormatter(SqlParseFormatter())
+    logger.addHandler(handler)
+
+    if config.getoption("--debug-sql"):
+        logger.setLevel(logging.INFO)
+
+
+@pytest.fixture(scope="function")
+def sql_session(request):
+    """Create a new SQLAlchemy session for testing."""
+
+    engine = create_engine("sqlite:///:memory:")
+
+    @event.listens_for(engine, "connect")
+    def set_sqlite_pragma(dbapi_connection, _connection_record):
+        cursor = dbapi_connection.cursor()
+        cursor.execute("PRAGMA foreign_keys=ON")
+        cursor.close()
+
+    Base.metadata.create_all(engine)
+    with Session(engine) as sql_session:
+        yield sql_session
+    sql_session.close()
+
+
+# FIXME: Declaring this hook seems to have a side effect where the database does not
+#        get reset between tests.
+# @pytest.hookimpl(trylast=True)
+# def pytest_runtest_call(item: pytest.Item):
+#     """Hook to format SQL statements in OperationalError exceptions."""
+#     try:
+#         item.runtest()
+#     except OperationalError as e:
+#         if e.statement is not None:
+#             formatted_sql = sqlparse.format(e.statement, reindent=True, keyword_case="upper")
+#             e.statement = "\n" + formatted_sql + "\n"
+#         raise e