---

name: run-pytest-tests description: Standard procedure for running pytest tests in the airline-discount-ml project with proper Python environment configuration.

Running Pytest Tests

When the user wants to run tests, always use the configured Python environment and follow these standardized procedures.

Prerequisites

1. Python environment must be configured:

   Copycd airline-discount-ml
   # Ensure .venv or venv is activated
   

2. Dependencies must be installed:

   Copypip install -e ".[dev]"
   # or
   pip install -r requirements.txt
   

Standard Test Execution Procedures

Run All Tests

Copycd airline-discount-ml
pytest tests/ -v
# or
make test

Run Specific Test File

Copycd airline-discount-ml
pytest tests/models/test_discount_predictor.py -v

Run Specific Test Function

Copycd airline-discount-ml
pytest tests/models/test_discount_predictor.py::test_fit_validates_empty_X -v

Run Tests Matching Pattern

Use -k flag to run tests matching a pattern:

Copycd airline-discount-ml
pytest -k "validate" -v         # All tests with "validate" in name
pytest -k "discount_predictor" -v   # All tests in discount_predictor
pytest -k "not slow" -v         # Exclude tests marked as slow

Run Only Failed Tests

Copycd airline-discount-ml
pytest --lf                      # Last failed
pytest --ff                      # Failed first, then rest

Quiet Mode (Summary Only)

Copycd airline-discount-ml
pytest tests/ -q                 # Minimal output
pytest tests/models/ --tb=no -q  # No traceback, quiet

Test Output Formats

Verbose Mode (-v)

Shows individual test names and PASS/FAIL status:

Copytests/models/test_discount_predictor.py::test_fit_validates_empty_X PASSED
tests/models/test_discount_predictor.py::test_predict_before_fit_raises PASSED

Very Verbose Mode (-vv)

Shows test names with full assertion details:

Copypytest tests/ -vv

Show Print Statements (-s)

Displays print/stdout from tests:

Copypytest tests/models/test_discount_predictor.py -s

Test Selection by Markers

Run Only Integration Tests

Copypytest -m integration -v

Exclude Slow Tests

Copypytest -m "not slow" -v

Expected Output

Successful Run

Copy======================== test session starts =========================
platform linux -- Python 3.11.9, pytest-9.0.2, pluggy-1.6.0
rootdir: /path/to/airline-discount-ml
configfile: pytest.ini
collected 42 items

tests/models/test_discount_predictor.py ............    [ 28%]
tests/models/test_passenger_profiler.py ............ [ 57%]
tests/training/test_train.py ..........              [ 81%]
tests/training/test_evaluate.py ........             [100%]

========================= 42 passed in 6.32s =========================

Failed Test

CopyFAILED tests/models/test_discount_predictor.py::test_example - AssertionError: ...

Troubleshooting

ModuleNotFoundError: No module named 'src'

Solution: Ensure you're in the airline-discount-ml directory and Python can find the src package:

Copycd airline-discount-ml
export PYTHONPATH=.
pytest tests/ -v

Or install in development mode:

Copypip install -e .

Tests Hang or Timeout

Solution: Use timeout or run in isolated mode:

Copypytest tests/ --timeout=10     # 10 second timeout per test
pytest tests/ -n auto          # Parallel execution (requires pytest-xdist)

Import Errors in Test Files

Solution: Check that:

1. __init__.py exists in tests/ subdirectories
2. Imports use absolute paths: from src.models import DiscountPredictor
3. Tests are in correct location (tests/ folder structure mirrors src/)

Pytest Not Found

Solution: Install pytest in the correct environment:

Copycd airline-discount-ml
source venv/bin/activate  # or .venv/bin/activate
pip install pytest pytest-cov

Quick Reference

Configuration

Tests are configured via pytest.ini:

Copy[pytest]
testpaths = tests
pythonpath = .
python_files = test_*.py *_test.py
python_classes = Test*
python_functions = test_*
addopts = -v --strict-markers