Add repo tests and fix build

Content.Tests/Content.Tests.csproj

@@ -0,0 +1,25 @@
+<Project Sdk="Microsoft.NET.Sdk">
+  <Import Project="..\RobustToolbox\MSBuild\Robust.Properties.targets" />
+
+  <PropertyGroup>
+    <IsPackable>false</IsPackable>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+    <WarningsAsErrors>nullable</WarningsAsErrors>
+    <AppendTargetFrameworkToOutputPath>false</AppendTargetFrameworkToOutputPath>
+    <OutputPath>..\bin\Content.Tests\</OutputPath>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="Microsoft.NET.Test.Sdk" />
+    <PackageReference Include="NUnit" />
+    <PackageReference Include="NUnit3TestAdapter" />
+    <PackageReference Include="NUnit.Analyzers" PrivateAssets="All" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\Content.Client\Content.Client.csproj" />
+    <ProjectReference Include="..\Content.Server\Content.Server.csproj" />
+    <ProjectReference Include="..\RobustToolbox\Robust.UnitTesting\Robust.UnitTesting.csproj" />
+  </ItemGroup>
+</Project>

Content.Tests/StartupTest.cs

@@ -0,0 +1,94 @@
+using Content.Client;
+using NUnit.Framework;
+using Robust.Server.Player;
+using Robust.Shared.Enums;
+using Robust.Shared.IoC;
+using Robust.Shared.Network;
+using Robust.Shared.Player;
+using Robust.UnitTesting;
+
+namespace Content.Tests;
+
+[TestFixture]
+public sealed class StartupTest : RobustIntegrationTest
+{
+    [Test]
+    public async Task ServerStarts()
+    {
+        var server = StartServer(ServerOptions());
+
+        await server.WaitIdleAsync();
+
+        Assert.That(server.IsAlive, Is.True);
+        Assert.That(server.UnhandledException, Is.Null);
+    }
+
+    [Test]
+    public async Task ClientStarts()
+    {
+        var client = StartClient(ClientOptions());
+
+        await client.WaitIdleAsync();
+
+        Assert.That(client.IsAlive, Is.True);
+        Assert.That(client.UnhandledException, Is.Null);
+    }
+
+    [Test]
+    public async Task ClientConnectsToServer()
+    {
+        await using var pair = await StartConnectedPair(ServerOptions(), ClientOptions(), "TemplateTester");
+        var server = pair.Server;
+        var client = pair.Client;
+
+        await RunTicksSync(server, client, 10);
+
+        await server.WaitAssertion(() =>
+        {
+            var playerManager = IoCManager.Resolve<IPlayerManager>();
+
+            Assert.That(playerManager.PlayerCount, Is.EqualTo(1));
+            Assert.That(playerManager.Sessions, Has.One.Matches<ICommonSession>(
+                session => session.Status == SessionStatus.Connected && session.Channel.IsConnected));
+        });
+
+        await client.WaitAssertion(() =>
+        {
+            var netManager = IoCManager.Resolve<IClientNetManager>();
+
+            Assert.That(netManager.IsConnected, Is.True);
+            Assert.That(netManager.ServerChannel, Is.Not.Null);
+            Assert.That(netManager.ServerChannel!.IsConnected, Is.True);
+        });
+    }
+
+    private static ServerIntegrationOptions ServerOptions()
+    {
+        return new ServerIntegrationOptions
+        {
+            ContentStart = true,
+            ContentAssemblies = [typeof(Content.Server.EntryPoint).Assembly],
+            Options = new Robust.Server.ServerOptions
+            {
+                ContentModulePrefix = "Content.",
+                LoadConfigAndUserData = false,
+                LoadContentResources = false,
+            },
+        };
+    }
+
+    private static ClientIntegrationOptions ClientOptions()
+    {
+        return new ClientIntegrationOptions
+        {
+            ContentStart = true,
+            ContentAssemblies = [typeof(EntryPoint).Assembly],
+            Options = new Robust.Client.GameControllerOptions
+            {
+                ContentModulePrefix = "Content.",
+                LoadConfigAndUserData = false,
+                LoadContentResources = false,
+            },
+        };
+    }
+}