Sample chat application built with netcore, F#, Akka.net and Fable.
- dotnet SDK 2.0.0 or higher
- .NET Framework 4.6.1 Developer Pack to run e2e tests
- node.js 4.8.2 or higher
- yarn (
npm i yarn -g) - npm5: JS package manager
- restore dependencies and build application:
fake build - run the application:
fake build -- start
More commands:
fake build -- clean buildfake build -- restorefake build -- build-- just build, no restore
Alternatively follow the instruction below:
- change current folder to
src/Clientfolder:cd src/Client - Install JS dependencies:
yarn - Build client bundle:
yarn build - chdir to
src/Serverfolder:cd ..\Server - Install F# dependencies:
dotnet restore - Run the server:
dotnet run - Head your browser to
http://localhost:8083/
- Start the server by starting
dotnet runinsrc/Serverfolder - Navigate to
src/Clientfolder - Start Fable daemon and Webpack dev server:
yarn start - In your browser, open: http://localhost:8080/
- Enjoy HMR (hotload module reload) experience
E2e tests are based on canopy and webdriver so currently I know it runs on Windows. I have no idea how to run in non-windows environment.
- run the tests:
fake build -- test - stop script by typing
qthen pressingEnter
or follow these steps:
- start the server
- Move to
test/e2efolder:cd test\e2e - run the tests:
dotnet run
Tests should be run on clean server, but after server became persistent this condition is usually not met (consider cleaning the src/Server/CHAT_DATA folder ny hands).
FsChat supports both permanent users, authorized via goodle or github account, and anonymous ones, those who provide only nickname.
In order to support the google/fb authentication scenario, fill in the client/secret in the CHAT_DATA/suave.oauth.config file. In case you do not see this file, run the server once and the file will be created automatically.
FsChat backend is based on Akka.Streams. The entry point is a GroupChatFlow module which implements the actor, serving group chat.
UserSessionFlow defines the flows for user and control messages, brings everything together and exposes flow for user session.
AboutFlow is an example of implementing channel with specific purpose, other than chatting
ChatServer is an actor which purpose is to keep the channel list. It's responsible for creating/dropping the channels.
UserStore is an actor which purpose is to know all users logged in. It supposed to be made persistent but it does not work for some reason (I created issue).
SocketFlow implements a flow decorating the server-side web socket.
Akkling is an unofficial Akka.NET API for F#. It's not just wrapper around Akka.NET API, but introduces some cool concepts such as Effects, typed actors and many more.
Client is written on F# with the help of Fable and Elmish (library?, framework?). Fable is absolutely mature technology, Elmish is just great.
After client is authenticated all communication between client and server is carried via WebSockets. The protocol is defined in src/Shared/ChatProtocol.fs file which is shared between client and server projects.
Server implementation demonstrates using Akka Persistance to restore server state after restart. It's based on event sourcing. However the server destroys the channels when all users are gone. So all channels created by users are non-permanent and will unlikely be restored after restart.