feat: Add integration test wrapping simplexity/run.py

[ealt]

Closes #84

Summary

Adds integration test that wraps simplexity/run.py to test the complete end-to-end workflow.

Changes

• Created tests/configs/integration_test.yaml with Hydra configuration for testing
• Created tests/test_integration.py that wraps the train_model function from run.py
• Uses local file system for persistence and logging (no external dependencies)
• Uses TransformerLens (penzai transformer) model as requested

Test Coverage

The integration test verifies:

• Configuration loading via Hydra
• Model training using run.py
• Loss decreases during training
• Checkpoints and logs are created
• Validation runs correctly

🤖 Generated with Claude Code

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Note

Adds an end-to-end integration test suite for run.py with a minimal Hydra config, verifying training, checkpoints/logs, loss decrease, and validation.

• Tests:
  • tests/test_integration.py adds integration tests around train_model:
    • End-to-end run verifies training completes, reasonable loss, logs, and checkpoints (including step-10).
    • Confirms loss decreases with more training steps using consistent seeding.
    • Validates that periodic validation executes and is logged.
• Config:
  • tests/configs/integration_test.yaml introduces a compact Hydra config for testing:
    • Small transformer model and reduced training/validation settings.
    • File-based logging and local checkpointing with overridable paths.

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[Copilot]

Pull Request Overview

This PR adds comprehensive integration tests for the Simplexity training workflow, providing end-to-end testing by wrapping the simplexity/run.py functionality.

Key changes:

• Created integration test configuration for fast, lightweight testing
• Implemented three test scenarios covering basic workflow, loss validation, and validation functionality
• Added temporary directory management for isolated test execution

Reviewed Changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 2 comments.

File	Description
tests/test_integration.py	Main integration test file with three test functions covering end-to-end workflow validation
tests/configs/integration_test.yaml	Hydra configuration optimized for testing with small model parameters and fast execution

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[Copilot]

Using hardcoded /tmp/ paths is not portable across operating systems (Windows doesn't have /tmp/). Consider using a relative path or letting the test override this value entirely.

Suggested change

	file_path: /tmp/simplexity_test_logs/test.log
	persistence:
	instance:
	directory: /tmp/simplexity_test_checkpoints
	file_path: logs/test.log
	persistence:
	instance:
	directory: checkpoints

[Copilot]

Using hardcoded /tmp/ paths is not portable across operating systems (Windows doesn't have /tmp/). Consider using a relative path or letting the test override this value entirely.

Suggested change

	file_path: /tmp/simplexity_test_logs/test.log
	persistence:
	instance:
	directory: /tmp/simplexity_test_checkpoints
	file_path: logs/test.log
	persistence:
	instance:
	directory: checkpoints

[claude]

Code Review for PR #85: Integration Test for simplexity/run.py

Thank you for adding this comprehensive integration test suite! This addresses issue #84 and significantly improves test coverage.

Strengths

• Well-structured test suite with three focused test functions
• Proper resource cleanup using tempfile.TemporaryDirectory()
• Good Hydra integration with initialize_config_dir and compose
• Appropriate assertions for file existence, loss values, and directories
• Follows project conventions from CLAUDE.md

Suggestions for Improvement

1. Type Annotations: Add type hints (-> None) to test functions per CLAUDE.md guidelines

2. Docstrings: Add detailed Google-style docstrings documenting test objectives

3. Specific Assertions: Add minimum improvement threshold in loss decrease test and verify log content patterns

4. Configuration: Consider using timestamp pattern for run_name like main config

5. Error Handling: Add tests for failure scenarios (invalid config, missing fields)

6. Test Isolation: Consider pytest fixtures for clean state between tests

Potential Issues

• Race condition risk with /tmp/simplexity_test_* in parallel runs
• Validation test only checks file exists, not validation-specific content

Performance & Security

• Appropriately minimal test config for fast execution
• No security concerns - proper cleanup and no hardcoded credentials

Test Coverage

Currently covers training workflow, config loading, checkpoints, logging, validation, and loss tracking. Consider adding tests for checkpoint loading and edge cases.

Overall Assessment

Solid integration testing addition. Clean, well-organized code. With suggested improvements (especially type hints and specific assertions), this will be excellent.

Recommendation: Approve with minor suggestions.

Great work!