To launch the project you first have to create a file named config.yaml to setup the hostname and a port to listen to.
On linux systems do:
(In both sub-projects (client/web and server)
touch config.yaml
And create the following entries for local development:
hostname: localhost
port: whateverYouWant
Use whatever port you'd like (e.g.: 4040) and use it on both projects
Then to launch the server, cd into the server directory and type dart main.dart
if you want the checked mode type dart -c main.dart
The client must be launched with another port number (e.g.: not 4040)
In another terminal you can launch the client with the following command : pub serve --port=<another port>
###Notes
Don't forget to pub get in each project (client, server) to fetch the necessary packages