Getting started

This first part of the book covers the decisions and steps that come before writing any package code. There are two distinct situations you might be in: starting a new package from scratch, or contributing to a package that already exists. Both are covered here.

The chapters are organised as follows:

• Scope asks the most important question of all: is this package actually needed? It walks through how to evaluate whether new functionality warrants a new package, whether it belongs inside an existing one, or whether it is already covered by the ecosystem.

• Ecosystem gives an overview of the full set of packages in the Tidy R OMOP CDM ecosystem. Understanding the landscape — which packages exist, what they do, and how they depend on each other — is essential before making scope decisions or choosing what to import.

• Contributing to a package covers the workflow for contributing to an existing package: how to open and respond to GitHub issues, how to write good pull requests, and what to expect from code review.

• Set up your environment walks through the practical steps to get a new package off the ground: creating the package skeleton, adding a licence, writing a first function, setting up tests, a README, a documentation website, and GitHub.