How to do development of the core of nRF Connect for Desktop

Developing the core of nRF Connect for Desktop is a bit different than developing an app for it.

As you have read in the architecture summary the core is split up over two projects: pc-nrfconnect-launcher and pc-nrfconnect-shared.

These projects are responsible for multiple things. So there could be several motivations for working on it: Most probably you want to change the launcher or code that is common for the apps.

Prerequisites

Besides the general prerequisites you may need some additional ones for developing the core:

Linux

Install additionally required packages for building the project on Ubuntu Linux:

apt-get install build-essential python2.7 libudev-dev libgconf-2-4

Windows

Install additionally required tools and configurations using Microsoft’s windows-build-tools from an elevated PowerShell or CMD.exe (run as Administrator):

npm install --global --production windows-build-tools

macOS

With macOS you already should have everything installed when you fulfill the general prerequisites.

Compilation of native modules

The project depends on pc-ble-driver-js and pc-nrfjprog-js which are native modules. Pre-compiled binaries for these modules are provided for recent Node.js versions on Windows, macOS, and Linux. However, if binaries do not exist for your platform/Node.js version, then refer to the pc-ble-driver-js README which describes requirements for compilation.

Running the launcher from source

Fetch the source from https://github.com/NordicSemiconductor/pc-nrfconnect-launcher and like on most Node.js projects, you need to install the dependencies once at the beginning with npm install and only need to repeat that later if the dependencies change.

Start the continuous compilation by running:

npm run watch

This will transpile and bundle all code into the dist directory. The process will watch for changes to source code, and re-bundle to dist on each change.

Now, open a separate terminal window and run:

npm run app

This will open Electron, which loads its content from dist. This instance also uses the apps it finds in your ~/.nrfconnect-apps directory. Thus if you also have a binary installation of nRF Connect for Desktop or develop local apps, the same apps will show up in this instance too.

Developing common code in pc-nrfconnect-shared

When you are developing common code in pc-nrfconnect-shared and you want to check the changes quickly in the launcher or an app the steps above are not sufficient, because by default the launcher will include a released version of pc-nrfconnect-shared from GitHub, not your local one. But with some additional effort you can achieve this by leveraging npm-link:

1. Have both, pc-nrfconnect-launcher and pc-nrfconnect-shared checked out into directories next to each other.
2. In the directory pc-nrfconnect-launcher run

   npm install; npm link ../pc-nrfconnect-shared
   

3. In the directory pc-nrfconnect-shared run

   npm ci --prod
   

With this setup, you can make changes in pc-nrfconnect-shared, then recompile pc-nrfconnect-launcher (pc-nrfconnect-shared does not need to be compiled), and immediately see the effects of the changes in pc-nrfconnect-shared. Usually the best setup is again to use npm run dev in pc-nrfconnect-launcher, as described above in “Running the launcher from source”.

If you forget to run npm ci --prod in pc-nrfconnect-shared, you may get errors because of conflicting package versions, especially of react and react-redux.

Caveat:

If you later run npm install in the directory pc-nrfconnect-launcher (e.g. because you install additional packages), the link to pc-nrfconnect-shared often gets lost. In that case you usually have to repeat running npm link ../pc-nrfconnect-shared in the directory pc-nrfconnect-launcher and then npm ci --prod in the directory pc-nrfconnect-shared.

If you later run npm install in the directory pc-nrfconnect-shared (e.g. because you install additional packages there), you may need to repeat running npm ci --prod in that directory.

Because npm ci --prod does not install the development dependencies, you cannot run the tests successfully in pc-nrfconnect-shared at that moment. Before you want to run the tests again, execute npm ci and you will also have the development dependencies installed again.

Testing

Relevant scripts for different testing needs:

• npm run check: Run static checks on the source
• npm test: Run the unit tests once
• npm run test-e2e: The launcher additionally included end-to-end tests

Installing the Electron dev tools

During development the React DevTools and the Redux DevTools are really handy. The easiest way to install them is to run

npm run install-devtools

when you have the source of the core checked out as described above. You only need to run this command once, the tools will stay installed in subsequent runs of Electron.

If you want to remove all dev tools later run

npm run remove-devtools