Contributing to lazycogs¶

Development setup¶

lazycogs uses uv for dependency management. Install it first if you haven't already.

Clone the repo and install the dev dependencies:

git clone https://github.com/developmentseed/lazycogs.git
cd lazycogs
uv sync

Install the pre-commit hooks so that ruff runs automatically before each commit:

uv run pre-commit install

Running tests¶

uv run pytest

The test suite uses synthetic COG fixtures generated at runtime — no external data required.

Benchmarks¶

Benchmarks live in tests/benchmarks/ and are excluded from the default test run. They require a local Sentinel-2 dataset that you download once before running:

uv run python scripts/prepare_benchmark_data.py

This queries the Element84 Earth Search STAC API, downloads a small set of COG assets to .benchmark_data/, and writes local parquet index files. Pass --overwrite to re-download if needed.

Once the data is in place:

uv run pytest tests/benchmarks --benchmark-enable

Building docs¶

Install the docs dependencies and serve the site locally:

uv run --group docs mkdocs serve