mlx-knife/TESTING.md

MLX Knife Testing Guide

Current Status

✅ 131/131 tests passing (August 2025)
✅ Apple Silicon verified (M1/M2/M3)
✅ Python 3.9-3.13 compatible
✅ Beta ready - comprehensive testing with real model execution

Quick Start

# Install with test dependencies
pip install -e ".[test]"

# Download test model (required for most tests)
mlxk pull mlx-community/Phi-3-mini-4k-instruct-4bit

# Run all tests
pytest

# Fast unit tests only
pytest tests/unit/

# Before committing
ruff check mlx_knife/ --fix && mypy mlx_knife/ && pytest

Why Local Testing?

MLX Knife requires Apple Silicon hardware and real MLX models for comprehensive testing:

• Hardware Requirement: MLX framework only runs on Apple Silicon (M1/M2/M3)
• Model Requirement: Tests use actual models (4GB+) for realistic validation
• Industry Standard: Local testing is normal for MLX projects
• Quality Assurance: Real hardware testing ensures actual functionality

This approach ensures our tests reflect real-world usage, not mocked behavior.

Test Structure

tests/
├── conftest.py                     # Shared fixtures and utilities
├── integration/                    # System-level integration tests (85+ tests)
│   ├── test_core_functionality.py      # Basic CLI operations
│   ├── test_health_checks.py           # Model corruption detection  
│   ├── test_issue_14.py               # Issue #14: Chat self-conversation fix
│   ├── test_issue_15_16.py            # Issues #15/#16: Dynamic token limits
│   ├── test_process_lifecycle.py       # Process management & cleanup
│   ├── test_run_command_advanced.py    # Run command edge cases
│   └── test_server_functionality.py    # OpenAI API server tests
└── unit/                          # Module-level unit tests (45+ tests)
    ├── test_cache_utils.py            # Cache management functions
    ├── test_cli.py                    # CLI argument parsing
    └── test_mlx_runner_memory.py     # Memory management tests

Test Prerequisites

Required Setup

1. Apple Silicon Mac (M1/M2/M3)
2. Python 3.9 or newer
3. Test dependencies installed:

   pip install -e ".[test]"
   

4. At least one MLX model:

   mlxk pull mlx-community/Phi-3-mini-4k-instruct-4bit
   

Optional Setup

For full test coverage, you may want additional models:

# Smaller model for quick tests
mlxk pull mlx-community/Phi-3-mini-128k-instruct-4bit

# Different architecture for variety
mlxk pull mlx-community/Mistral-7B-Instruct-v0.3-4bit

Test Commands

Basic Test Execution

# All tests (recommended before commits)
pytest

# Only integration tests (system-level)
pytest tests/integration/

# Only unit tests (fast)
pytest tests/unit/

# Verbose output
pytest -v

# Show test coverage
pytest --cov=mlx_knife --cov-report=html

Specific Test Categories

# Process lifecycle tests (critical for production)
pytest tests/integration/test_process_lifecycle.py -v

# Health check robustness (model corruption detection)
pytest tests/integration/test_health_checks.py -v

# Core functionality (basic CLI commands)
pytest tests/integration/test_core_functionality.py -v

# Advanced run command tests
pytest tests/integration/test_run_command_advanced.py -v

# Server functionality tests
pytest tests/integration/test_server_functionality.py -v

Test Filtering

# Run only basic operations tests
pytest -k "TestBasicOperations" -v

# Server tests are automatically excluded by default
# (no command needed - this is the default behavior)

# Skip tests requiring actual models
pytest -k "not requires_model" -v

# Run only process lifecycle tests
pytest -k "process_lifecycle or zombie" -v

# Run health check tests only
pytest -k "health" -v

Timeout and Performance

# Set custom timeout (default: 300s)
pytest --timeout=60

# Show slowest tests
pytest --durations=10

# Parallel execution (if pytest-xdist installed)
pytest -n auto

Python Version Compatibility

Verification Results (August 2025)

Python Version	Status	Tests Passing
3.9.6 (macOS)	✅ Verified	131/131
3.10.x	✅ Verified	131/131
3.11.x	✅ Verified	131/131
3.12.x	✅ Verified	131/131
3.13.x	✅ Verified	131/131

All versions tested with real MLX model execution (Phi-3-mini-4k-instruct-4bit).

Manual Multi-Python Testing

If you have multiple Python versions installed, you can verify compatibility:

# Run the multi-Python verification script
./test-multi-python.sh

# Or manually test specific versions
python3.9 -m venv test_39
source test_39/bin/activate
pip install -e ".[test]"
pytest
deactivate && rm -rf test_39

Code Quality & Development

Code Quality Tools

MLX Knife includes comprehensive code quality tools:

# Install development dependencies  
pip install -e ".[dev]"

# Automatic code formatting and linting
ruff check mlx_knife/ --fix

# Type checking with mypy
mypy mlx_knife/

# Complete development workflow
ruff check mlx_knife/ --fix && mypy mlx_knife/ && pytest

Development Workflow

Before committing changes:

#!/bin/bash
# pre-commit-check.sh - Run before committing
set -e

echo "🧪 Running MLX Knife pre-commit checks..."

# 1. Code style
echo "Checking code style..."
ruff check mlx_knife/ --fix

# 2. Type checking
echo "Checking types..."
mypy mlx_knife/

# 3. Quick smoke test
echo "Running quick tests..."
pytest tests/unit/ -v

echo "✅ All checks passed. Safe to commit!"

Local Development Testing

Adding New Tests

1. Integration tests go in tests/integration/
2. Unit tests go in tests/unit/
3. Use existing fixtures from conftest.py
4. Follow naming: test_*.py, Test* classes, test_* methods

Test Categories (Markers)

@pytest.mark.integration  # Slower system tests
@pytest.mark.unit         # Fast isolated tests  
@pytest.mark.slow         # Tests >30 seconds
@pytest.mark.requires_model  # Needs actual MLX model
@pytest.mark.network      # Requires internet
@pytest.mark.server       # Requires MLX Knife server (excluded from default pytest)

Mock Utilities

• mock_model_cache(): Creates fake model directories
• mlx_knife_process(): Manages subprocess lifecycle
• process_monitor(): Tracks zombie processes
• temp_cache_dir(): Isolated test environment

Test Philosophy

Following the "Process Hygiene over Edge-Case Perfection" principle:

1. Process Cleanliness: No zombies, no leaks ✅
2. Health Checks: Reliable corruption detection ✅
3. Core Operations: Basic functionality works ✅
4. Error Handling: Graceful failures ✅

The test suite validates production readiness with real Apple Silicon hardware and actual MLX models.

Troubleshooting

Common Issues

Tests hang forever:

pytest --timeout=60

Import errors:

pip install -e ".[test]"

Process cleanup issues:

ps aux | grep mlx_knife  # Check for zombies

Cache conflicts:

export HF_HOME="/tmp/test_cache"
pytest --cache-clear

Test Environment

# Clean test run
rm -rf .pytest_cache __pycache__
pytest tests/ -v --cache-clear

# Debug specific test
pytest tests/integration/test_health_checks.py::TestHealthCheckRobustness::test_healthy_model_detection -v -s

Contributing Test Results

When submitting PRs, please include:

1. Your test environment:

   • macOS version
   • Apple Silicon chip (M1/M2/M3)
   • Python version
   • Which model(s) you tested with

2. Test results summary:

   Platform: macOS 14.5, M2 Pro
   Python: 3.11.6
   Model: Phi-3-mini-4k-instruct-4bit
   Results: 114/114 tests passed
   

3. Any issues encountered and how you resolved them

Summary

MLX Knife 1.0.4 Testing Status:

✅ Production Ready - 114/114 tests passing
✅ Multi-Python Support - Python 3.9-3.13 verified
✅ Code Quality - ruff/mypy integration working
✅ Real Model Testing - Phi-3-mini execution confirmed
✅ Memory Management - Context managers prevent leaks
✅ Exception Safety - Context managers ensure cleanup
✅ Chat Bug Fixed - Issue #14 self-conversation regression tests added ✅ Server Tests - Automated MLX Knife server testing infrastructure

This comprehensive testing framework validates MLX Knife's production readiness through local testing on real Apple Silicon hardware with actual MLX models.

Server-Based Testing (Advanced)

Some tests require a running MLX Knife server with loaded models. These tests are marked with @pytest.mark.server and are not run by default with pytest.

Why Separate Server Tests?

• Test count varies by loaded models (makes CI reporting inconsistent)
• Large memory requirements - need different models for different RAM sizes
• Longer execution time - each model needs to load individually
• Manual setup required - need to download appropriate models first

Prerequisites for Server Tests

System RAM	Recommended Models	Commands
16GB	Small models only	mlxk pull mlx-community/Qwen2.5-0.5B-Instruct-4bit mlxk pull mlx-community/Llama-3.2-1B-Instruct-4bit mlxk pull mlx-community/Llama-3.2-3B-Instruct-4bit
32GB	+ Medium models	mlxk pull mlx-community/Phi-3-mini-4k-instruct-4bit mlxk pull mlx-community/Mistral-7B-Instruct-v0.2-4bit mlxk pull mlx-community/Mixtral-8x7B-Instruct-v0.1-4bit
64GB	+ Large models	mlxk pull mlx-community/Mistral-Small-3.2-24B-Instruct-2506-4bit mlxk pull mlx-community/Qwen3-30B-A3B-Instruct-2507-4bit mlxk pull mlx-community/Llama-3.3-70B-Instruct-4bit
96GB+	+ Huge models	mlxk pull mlx-community/Qwen3-Coder-480B-A35B-Instruct-4bit

Running Server Tests

Issue #14 Regression Tests (Chat Self-Conversation Bug):

# Set environment
export HF_HOME=/path/to/your/cache

# Smoke test first (see which models are available)
python tests/integration/test_issue_14.py

# Run server tests only (excluded from default pytest)
pytest -m server -v

# Run specific Issue #14 tests
pytest tests/integration/test_issue_14.py -m server -v

Expected Output:

🦫 MLX Knife Issue #14 Test - Smoke Test
==================================================
📊 Safe models for this system: 6
💾 System RAM: 64GB total, 40GB available

  🎯 mlx-community/Mistral-7B-Instruct-v0.2-4bit
     └─ Size: 7B, RAM needed: 8GB
  🎯 mlx-community/Llama-3.2-3B-Instruct-4bit  
     └─ Size: 3B, RAM needed: 4GB
  [...]

========== test session starts ==========
tests/integration/test_issue_14.py::test_server_health[mlx_server] PASSED
tests/integration/test_issue_14.py::test_issue_14_self_conversation_regression_original[mlx-community/Mistral-7B-Instruct-v0.2-4bit-7B-8] PASSED
[...6 more model tests...]
========== 7 passed in 45.23s ==========

Future Server Tests (Planned)

Issue #15 - Token Limit vs Stop Token Race Condition:

pytest tests/integration/test_issue_15.py -m server -v

Issue #16 - Interactive vs Server Token Policies:

pytest tests/integration/test_issue_16.py -m server -v

Troubleshooting Server Tests

Permission warnings are normal:

WARNING: ⚠️  Cannot scan network connections (permission denied)
INFO: 🔧 Falling back to process-based cleanup only

This is expected on macOS - the tests continue with process-based cleanup.

Memory issues:

• Tests automatically skip models exceeding 80% available RAM
• Use smaller models if you see consistent memory failures
• Consider external SSD for model cache to reduce memory pressure

Server startup failures:

# Debug server manually
python -m mlx_knife.cli server --port 8000

# Check model health  
mlxk health

# Verify environment
echo $HF_HOME

Adding New Server Tests

When contributing server-based tests:

@pytest.mark.server
def test_new_feature(mlx_server, model_name: str, size_str: str, ram_needed: int):
    """Test new feature with MLX models.""" 
    # Use mlx_server fixture for automatic server management
    # Test implementation here

1. Mark with @pytest.mark.server - excludes from default pytest
2. Use mlx_server fixture - automatic server lifecycle management
3. Test RAM requirements - use get_safe_models_for_system() helper
4. Document in TESTING.md - add to this guide