DRAFT: google-cloud-spanner-driver project setup

[bhatt4982]

No description provided.

[gemini-code-assist]

Summary of Changes

Hello @bhatt4982, I'm Gemini Code Assist¹! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!

This pull request lays the groundwork for a new Python driver for Google Cloud Spanner. It focuses on creating a complete, self-contained project with all necessary configuration, licensing, and documentation. The primary goal is to provide a DBAPI 2.0 compliant interface, enabling Python applications to interact with Spanner in a standardized manner. The inclusion of extensive testing infrastructure ensures the reliability and correctness of the driver's implementation from its inception.

Highlights

• New Project Initialization: This pull request establishes the foundational structure for the google-cloud-spanner-driver Python project, including standard project files like .gitignore, LICENSE, README.md, and pyproject.toml.
• DBAPI 2.0 Compliance: Core Connection and Cursor classes are implemented to adhere to the Python Database API Specification v2.0, providing standardized interfaces for interacting with Google Cloud Spanner.
• Comprehensive Testing Framework: A robust testing suite has been introduced, encompassing unit tests with mocked dependencies, system tests for both emulator and production environments, and a dedicated compliance test suite to validate DBAPI 2.0 adherence. nox is configured to automate these testing workflows.
• Emulator Support: The driver explicitly supports connecting to the Spanner Emulator, with clear usage examples and configuration options provided in the README.md and testing helpers.

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[gemini-code-assist]

Code Review

This pull request sets up the initial project structure for the google-cloud-spanner-driver, including basic DBAPI 2.0 compliance, error handling, and testing infrastructure. The changes introduce necessary files like .gitignore, LICENSE, README.md, pyproject.toml, setup.py, noxfile.py, and the core driver components (__init__.py, connection.py, cursor.py, dbapi.py, errors.py, types.py). Unit, compliance, and system tests are also included, along with helper utilities. While the overall setup is comprehensive, there are several critical and high-severity issues related to DBAPI compliance, error handling, and type mapping that need to be addressed before this driver can be considered robust. Specifically, silent exception handling in transaction methods, a mismatch between declared and actual parameter styles, and incomplete data type conversions are significant concerns.

[gemini-code-assist]

Catching Exception and then passing silently in the commit method can hide critical database errors, leading to data inconsistency or unexpected behavior without proper notification. It's crucial to either re-raise a mapped DBAPI error or handle the exception explicitly in a way that informs the user about the failure.

Consider re-raising a mapped error for better error visibility and handling.

Suggested change

	except Exception as e:
	# raise errors.map_spanner_error(e)
	logger.debug(f"Commit failed {e}")
	pass
	except Exception as e:
	raise errors.map_spanner_error(e)

[gemini-code-assist]

Similar to the commit method, catching Exception and passing silently in rollback can mask important issues. While rollback might sometimes be best-effort, silent failures can lead to an inconsistent state. It's generally better to re-raise a mapped DBAPI error to ensure the application is aware of the failure.

Consider re-raising a mapped error for better error visibility and handling.

Suggested change

	except Exception as e:
	# raise errors.map_spanner_error(e)
	logger.debug(f"Rollback failed {e}")
	except Exception as e:
	raise errors.map_spanner_error(e)

[gemini-code-assist]

The test_execute_with_params is currently skipped because parameters are "not yet handled". This indicates a critical gap in the driver's functionality and DBAPI 2.0 compliance. A core feature of DBAPI is the ability to execute queries with parameters to prevent SQL injection and improve performance.

This test should be enabled and passing before the driver is considered functional.