Contributor guide

Note: This document at present is for only code contributors. We should expand it so that it covers reporting bugs, filing issues, and writing docs.

Questions & online chat Discord

We have a Discord server to discuss Libplanet. There are some channels for purposes in the Libplanet category:

  • #announcement: Maintainers announce events like our roadmap or local events.
  • #users: Chat with game programmers who use Libplanet. Ask questions to use Libplanet for your games.
  • #development: Chat with maintainers and contributors of Libplanet. Ask questions to hack Libplanet and to make a patch for it.
  • #users-ko: The same purpose to #users, except you can speak Korean instead English here.
  • #development-ko: The same purpose to #development, except you can speak Korean instead English here.

Prerequisites

You need .NET Core SDK 2.2+ which provides the latest C# compiler and .NET VM. Read and follow the instruction to install .NET Core SDK on the .NET Core downloads page. FYI if you use macOS and Homebrew you can install it by brew cask install dotnet-sdk command.

Make sure that your .NET Core SDK is 2.2 or higher. You could show the version you are using by dotnet --info command.

If it's Windows please check if the environment variable named MSBuildSDKsPath refers to the proper version of .NET Core SDK. If you use Visual Studio 2017 (not 2019) you can only use .NET Core 2.2.105 at the highest. .NET Core SDK higher than the version 2.2.105 is not recognized by Visual Studio 2017.

Although it is not necessary, you should install a proper IDE for .NET (or an OmniSharp extension for your favorite editor — except it takes hours to properly configure and integrate with your editor). C# is not like JavaScript or Python; it is painful to code in C# without IDE.

Unless you already have your favorite setup, we recommend you to use Visual Studio Code. It is free, open source, and made by Microsoft, which made .NET as well. So Visual Studio Code has a first-party C# extension which works well together.

Build

The following command installs dependencies (required library packages) and builds the entire Libplanet solution:

dotnet build

Tests Build Status Codecov

We write as complete tests as possible to the corresponding implementation code. Going near to the code coverage 100% is one of our goals.

The Libplanet solution consists of several projects. Libplanet and Libplanet.Stun are actual implementations. These are built to Libplanet.dll and Libplanet.Stun.dll assemblies and packed into one NuGet package.

Libplanet.Tests is a test suite for the Libplanet.dll assembly, and Libplanet.Stun.Tests is a test suite for the Libplanet.Stun.dll assembly. Both depend on Xunit, and every namespace and class in these corresponds to one in Libplanet or Libplanet.Stun projects. If there's Libplanet.Foo.Bar class there also should be Libplanet.Tests.Foo.BarTest to test it.

To build and run unit tests at a time execute the below command:

dotnet test

TURN_SERVER_URL

Some tests depend on a TURN server. If TURN_SERVER_URL environment variable is set (the value looks like turn://user:password@host:3478/) these tests also run. Otherwise, these tests are skipped.

FYI there are several TURN implementations like Coturn and gortc/turn, or cloud offers like Xirsys.

xunit-unity-runner

Unity is one of our platforms we primarily target to support, so we've been testing Libplanet on the actual Unity runtime, and you could see whether it's passed on Azure Pipelines.

However, if it fails and it does not fail on other platforms but only Unity, you need to run Unity tests on your own machine so that you rapidily and repeatedly tinker things, make a try, and immediately get feedback from them.

Here's how to run Unity tests on your machine. We've made and used xunit-unity-runner to run Xunit tests on the actual Unity runtime, and our build jobs on Azure Pipelines also use this. This test runner is actually a Unity app, though it's not a game app. As of June 2019, there are executable binaries for Linux, macOS, and Windows. Its usage is simple. It's a CLI app that takes absolute paths to .NET assemblies (.dll) that consist of test classes (based on Xunit).

You can build these assemblies using msbuild -r Mono or .NET Framework provide. You can't build them using dotnet build command or dotnet msbuild, because the Unity runtime is not based on .NET Core but Mono, which is compatible with .NET Framework 4.6. Please be sure that Mono's bin directory is prior to .NET Core's one (or it's okay too if .NET Core is not installed at all). Mono or .NET Framework's msbuild could try to use .NET Core's version of several utilities during build, and this could cause some errors.

The way to execute the runner binary depend on the platform. For details, please read xunit-unity-runner's README. FYI you can use -h/--help option as well.

To sum up, the instruction is like below (the example is assuming Linux):

msbuild -r
xunit-unity-runner/StandaloneLinux64 \
  "`pwd`"/*.Tests/bin/Debug/net461/*.Tests.dll

Style convention

Please follow the existing coding convention. We are already using several static analyzers. They are automatically executed together with msbuild, and will warn you if there are any style errors.

You should also register Git hooks we commonly use:

git config core.hooksPath hooks

We highly recommend you to install an extension for EditorConfig in your favorite editor. Some recent editors have built-in support for EditorConfig, e.g., Rider (IntelliJ IDEA), Visual Studio. Many editors have an extension to support EditorConfig, e.g., Atom, Emacs, Vim, VS Code.

Benchmarks

In order to track performance improvements or regressions, we maintain a set of benchmarks and continuously measure them in the CI. You can run benchmarks on your local environment too:

dotnet run -p Libplanet.Benchmarks -c Release -- -j short -f "*"

Note that there is -j short; without this a whole set of benchmarks takes quite a long time. This will print like below:

|               Method | UnrollFactor |      Mean |      Error |    StdDev |
|--------------------- |------------- |----------:|-----------:|----------:|
|       MineBlockEmpty |           16 |  12.20 ms |  11.649 ms | 0.6385 ms |
|  MineBlockOneTran... |            1 |  14.54 ms |   3.602 ms | 0.1974 ms |
|                  ... |          ... |       ... |        ... |       ... |

You can measure only part of benchmarks by -f/--filtering them:

dotnet run -p Libplanet.Benchmarks -c Release -- -j short -f "*MineBlock*"

All benchmark code is placed under Libplanet.Benchmarks project. As our benchmarks are based on BenchmarkDotNet, please read their official docs for details.

Troubleshooting

I got the error like Fody is only supported on MSBuild 16 and above. Current version: 15.

Your .NET Core SDK version probably is outdated. Our recommended version is: 2.2.300.

  1. Download the lastest (as of June 2019) .NET Core SDK binary from the official website:

    https://dotnet.microsoft.com/download/dotnet-core/2.2#sdk-2.2.300

  2. Extract .tar.gz in proper directory.

  3. You could permanently add the following commands into your shell profile.

    export DOTNET_ROOT="$YOUR_DOTNET_INSTALLATION_PATH/dotnet"
export PATH="$PATH:$DOTNET_ROOT"