M4

"""Tests for m4.core.backends.base module. Tests cover: - QueryResult dataclass - Backend exceptions (BackendError, ConnectionError, etc.) - Backend protocol interface """ from m4.core.backends.base import ( Backend, BackendError, ConnectionError, QueryExecutionError, QueryResult, TableNotFoundError, ) class TestQueryResult: """Test QueryResult dataclass.""" def test_success_result(self): """Test creating a successful query result.""" result = QueryResult(data="test data", row_count=10) assert result.data == "test data" assert result.row_count == 10 assert result.truncated is False assert result.error is None assert result.success is True def test_truncated_result(self): """Test creating a truncated query result.""" result = QueryResult(data="test data", row_count=100, truncated=True) assert result.truncated is True assert result.success is True def test_error_result(self): """Test creating an error query result.""" result = QueryResult(data="", error="Query failed") assert result.error == "Query failed" assert result.success is False def test_empty_result(self): """Test creating an empty query result.""" result = QueryResult(data="No results found", row_count=0) assert result.row_count == 0 assert result.success is True class TestBackendErrors: """Test backend exception classes.""" def test_backend_error(self): """Test base BackendError.""" error = BackendError("test error", backend="duckdb") assert str(error) == "test error" assert error.message == "test error" assert error.backend == "duckdb" assert error.recoverable is False def test_backend_error_recoverable(self): """Test BackendError with recoverable flag.""" error = BackendError("test error", backend="bigquery", recoverable=True) assert error.recoverable is True def test_connection_error(self): """Test ConnectionError (always recoverable).""" error = ConnectionError("Connection failed", backend="duckdb") assert str(error) == "Connection failed" assert error.recoverable is True # Always recoverable def test_table_not_found_error(self): """Test TableNotFoundError.""" error = TableNotFoundError("patients", backend="duckdb") assert "patients" in str(error) assert error.table_name == "patients" assert error.recoverable is False def test_query_execution_error(self): """Test QueryExecutionError.""" error = QueryExecutionError( "Syntax error", sql="SELECT * FORM patients", # typo in FROM backend="duckdb", ) assert str(error) == "Syntax error" assert error.sql == "SELECT * FORM patients" assert error.recoverable is False class TestBackendProtocol: """Test Backend protocol structure.""" def test_backend_is_runtime_checkable(self): """Test that Backend protocol is runtime checkable.""" class MockBackend: name = "mock" def execute_query(self, sql, dataset): return QueryResult(data="test") def get_table_list(self, dataset): return [] def get_table_info(self, table_name, dataset): return QueryResult(data="") def get_sample_data(self, table_name, dataset, limit=3): return QueryResult(data="") def get_backend_info(self, dataset): return "Mock backend" mock = MockBackend() assert isinstance(mock, Backend) def test_incomplete_backend_not_recognized(self): """Test that incomplete backends are not recognized.""" class IncompleteBackend: # Missing required methods name = "incomplete" backend = IncompleteBackend() assert not isinstance(backend, Backend)