Bash language support for Atom-IDE. It's backed by mads-hartmann/bash-language-server.
You need to install that language server separately as it depends on native node modules.
npm i -g bash-language-server
Most of the interesting bits are happening in the server so you'll probably want to head over to the development guide to see the development flow for the server.
If not, here's how to work on the Atom client.
git clone git@github.com:mads-hartmann/ide-bash && cd ide-bash
npm install
apm link
If you want to inspect the communication between the Atom and the Bash language server then open the Developer Tools in Atom and execute the following piece of code in the Console.
atom.config.set('core.debugLSP', true)
Reload the window and you should see all the messages.