The Joplin source code is hosted on a [monorepo](https://en.wikipedia.org/wiki/Monorepo) and is managed using Yarn workspaces (as well as Lerna for publishing the packages).
lib | The core library, shared by all applications. It deals with things like synchronisation, encryption, import/export, database and pretty much all the app business logic
renderer | The Joplin Markdown and HTML renderer
tools | Tools used to build the apps and other tasks
There are also a few forks of existing packages under the "fork-*" name.
You can also run it under WSL 2. To do so, [follow these instructions](https://www.beekeeperstudio.io/blog/building-electron-windows-ubuntu-wsl2) to setup your environment.
First you need to setup React Native to build projects with native code. For this, follow the instructions in the [Setting up the development environment](https://reactnative.dev/docs/environment-setup) tutorial, in the "React Native CLI Quickstart" tab.
To test the extension please refer to the relevant pages for each browser: [Firefox](https://developer.mozilla.org/en-US/docs/Mozilla/Add-ons/WebExtensions/Your_first_WebExtension#Trying_it_out) / [Chrome](https://developer.chrome.com/docs/extensions/mv3/getstarted/). Please note that the extension in dev mode will only connect to a dev instance of the desktop app (and vice-versa).
To make changes to the application, you'll need to rebuild any TypeScript file you've changed. The simplest way to do this is to watch for changes from the root of the project. Simply run this command, and it should take care of the rest:
You can specify additional parameters when running the desktop or CLI application. To do so, add `--` to the `yarn start` command, followed by your flags. For example:
The application was originally written in JavaScript, however it has slowly been migrated to [TypeScript](https://www.typescriptlang.org/). New classes and files should be written in TypeScript. All compiled files are generated next to the .ts or .tsx file. So for example, if there's a file "lib/MyClass.ts", there will be a generated "lib/MyClass.js" next to it. It is implemented that way as it requires minimal changes to integrate TypeScript in the existing JavaScript code base.
If you'd like to auto-reload the desktop app on changes rather than having to quit and restart it manually each time, you can use [watchman-make](https://facebook.github.io/watchman/docs/watchman-make.html):
It still requires you to quit the application each time you want it to rebuild, but at least you don't have to re-run `"yarn start"` each time. Here's what the workflow loop looks like in practice:
Please read for the [Build Troubleshooting Document](https://github.com/laurent22/joplin/blob/dev/readme/dev/build_troubleshooting.md) for various tips on how to get the build working.
