Question

Your team maintains an internal action that formats and validates JSON configuration files. It must run identically on GitHub-hosted ubuntu, windows, and macos runners, must start with minimal overhead (no container pull), and its logic is complex enough that the team wants to write and unit-test it in TypeScript rather than orchestrating existing shell commands. Which action type best fits these requirements?

Accepted Answer

A JavaScript action with 'runs.using: node20' and a compiled 'dist/index.js' entry point

Answer

A Docker container action, using a multi-arch base image to cover all runner operating systems

Answer

A composite action that shells out to a locally installed formatter via multiple 'run' steps

Answer

A reusable workflow that calls a formatting job with a matrix over the three operating systems