Testing API Reference

Testing API Reference

Full public surface of ExpandedLib.Testing. For setup and worked examples see the Testing Harness page. Signatures are taken from test/ExpandedLib.Testing/.

TestWorld

Headless, in-process stand-in for a server world: in-memory block/BE store, a live BlockNetworkModSystem, and NSubstitute-faked accessors/API.

public sealed class TestWorld
{
    public TestWorld();

    // State:
    public Block Air { get; }
    public BlockNetworkModSystem Networks { get; }
    public IBlockAccessor Accessor { get; }
    public IServerWorldAccessor World { get; }
    public IGameCalendar Calendar { get; }
    public ICoreServerAPI Api { get; }
    public List<ItemStack> Drops { get; }

    // Setup:
    public TestWorld Attach(BlockEntity be);
    public TestWorld Initialize(BlockEntity be);
    public TestWorld RegisterNetwork(string networkType, Func<BlockNetworkModSystem, BlockNetwork> factory);
    public TestWorld Place(BlockPos pos, Block block, BlockEntity? be = null);
    public TestWorld RegisterBlockEntityFactory(string classname, Func<BlockEntity> factory);
    public TestWorld Register(Block block);
    public Item RegisterItem(string code, float meltingPoint = 0f);
    public Item? GetItem(AssetLocation? code);
    public Item? GetItem(int id);

    // Store access:
    public Block GetBlock(BlockPos pos);
    public BlockEntity? GetBlockEntity(BlockPos pos);

    // Graph:
    public void AddNode(BlockPos pos, string networkType);
    public void RemoveNode(BlockPos pos);
    public BlockNetwork? NetworkAt(BlockPos pos);

    // Time:
    public void Tick(int seconds = 1);                       // mirrors BlockNetworkModSystem.OnServerTick: OnTick(1f) per network
    public void FireBlockEntityTicks(float dt = 1f, int times = 1);   // fire RegisterGameTickListener callbacks
    public void AdvanceDays(double days);
}

Tick advances the network simulation; FireBlockEntityTicks fires the listeners block entities registered via RegisterGameTickListener (captured from the fake event API). It supports both the 1.22 RegisterGameTickListener overload (with BlockPos) and the legacy 1.20/1.21 one via #if GAME_GE_1_22.

Scene

Composition layer over TestWorld: lay out blocks/nodes/machines, advance them together, read back state.

public sealed class Scene
{
    public TestWorld World { get; }

    public Scene Network(string type, Func<BlockNetworkModSystem, BlockNetwork> factory);
    public Scene Block(BlockPos pos, Block block);
    public Scene Node(BlockPos pos, Block block, BlockEntity be, string networkType);
    public Scene Machine(BlockPos pos, Block block, BlockEntity be);
    public Scene Fill(BlockPos a, BlockPos b, Block block);
    public Scene Build();                                    // add all queued nodes to the graph (call once)
    public void Step(int seconds = 1);                       // fire BE ticks then network ticks, per second
    public TNet? NetworkAt<TNet>(BlockPos pos) where TNet : BlockNetwork;
    public TBe? EntityAt<TBe>(BlockPos pos) where TBe : BlockEntity;
}

Flow: Network(...) → Block/Node/Machine/Fill(...) → Build() once → Step(...) → query with NetworkAt<T> / EntityAt<T>.

SceneDiagram

Turns ASCII layouts into placements. Columns advance +X, rows advance +Z; each Layer sits at a fixed Y; Stack indexes layers bottom-to-top.

public sealed class SceneDiagram
{
    public SceneDiagram On(char glyph, Action<BlockPos> place);
    public SceneDiagram Layer(string ascii, int y = 0, int originX = 0, int originZ = 0);
    public SceneDiagram Stack(int baseY, int originX, int originZ, params string[] layers);
    public SceneDiagram Stack(int baseY, params string[] layers);
}

VsAssemblyResolver

public static class VsAssemblyResolver
{
    public static void Register();   // idempotent; hooks AppDomain.AssemblyResolve for the game DLLs
}

Resolves the install from [AssemblyMetadata("GameInstallEnv")] (env var such as VINTAGE_STORY, VINTAGE_STORY_121) or by walking up to .game/<slug> (slug from [AssemblyMetadata("GameSlug")], e.g. 1.22). Probes the install root, Lib/ and Mods/. Call from a [ModuleInitializer] before any test type loads. The harness itself also has an internal module initializer that calls it, but your test project should call it (plus TestLang.Init) explicitly — that is the established pattern.

TestLang

public static class TestLang
{
    public static void Init();   // idempotent; registers an echo-the-key "en" translation service
}

Returns the key unchanged from Lang.Get, so assert on numeric payloads, not localized labels.

ReflectionHelpers

public static class ReflectionHelpers
{
    public static void SetProperty(object target, string propertyName, object? value);
    public static void SetField(object target, string fieldName, object? value);
    public static object? GetField(object target, string fieldName);
    public static object? Invoke(object target, string methodName, params object?[] args);
}

All walk the base-class hierarchy and access non-public members.

TestBlocks

public static class TestBlocks
{
    public static T Configure<T>(T block, string code, int id, params (string key, string value)[] variants) where T : Block;
}

Assigns Code and BlockId, populates VariantStrict from the pairs, and wraps it in a relaxed dictionary (absent keys return null instead of throwing). Returns the block for chaining — this is how you build blocks without the asset-load pipeline.

var pipe = TestBlocks.Configure(new BlockPipe(), "ppex:pipe-straight-iron-ns", id: 1,
    ("material", "iron"), ("type", "straight"), ("orientation", "ns"));

Test doubles (ExpandedLib.Testing.Doubles)

StubNetwork : BlockNetwork

Medium-less concrete network for exercising the graph engine (add/remove/merge/fracture/rebuild) without gameplay state.

public sealed class StubNetwork : BlockNetwork
{
    public StubNetwork(BlockNetworkModSystem system, string networkType = "test");
    public override string NetworkType { get; }
    public string? Tag { get; set; }   // arbitrary marker that survives merge/split/inherit — assert state propagation
    public override void OnMerge(BlockNetwork other, IBlockAccessor world);
    public override void OnSplitFragment(BlockNetwork original, IBlockAccessor world);
    public override void InheritStateFrom(BlockNetwork source);
    public override void OnTick(IBlockAccessor world, float dt, BlockNetworkModSystem manager);   // empty
}

TestNetworkBlock : BlockNetworkNode

Minimal concrete node block with a configurable connector set; bypasses asset loading.

public sealed class TestNetworkBlock : BlockNetworkNode
{
    public override string NetworkType { get; }
    public override Dictionary<string, string[]> AllowedOrientations { get; }
    public static TestNetworkBlock Create(string networkType, string orientation, int id, string? code = null);
}

The orientation string is the connector set ("ns", "we", "nswe"). Default code is test:{networkType}-{orientation}-{id}.

CapturingNode : BlockEntity, INetworkNode

Records broadcasts and open-connector notifications so tests can assert propagation.

public sealed class CapturingNode : BlockEntity, INetworkNode
{
    public object? LastState { get; }
    public int UpdateCount { get; }
    public BlockFacing[]? LastOpenFaces { get; }
    public string? Orientation { get; set; }
    public string[] PossibleOrientations { get; set; }
    public string NetworkType { get; set; }

    public bool HasConnectorAt(BlockFacing face);                 // true if Orientation contains the face code
    public void OnOpenConnectorsChanged(BlockFacing[] openFaces);
    public void OnNetworkUpdate(object? state);                  // captures state, increments UpdateCount
}

SeverableNode : BlockEntityNetworkNode

A real node whose connectivity toggles at runtime, for testing dynamic fracture.

public sealed class SeverableNode : BlockEntityNetworkNode
{
    public bool Broken { get; set; }
    public override string NetworkType { get; set; }
    public override bool IsConnectionBroken();   // returns Broken — graph severs here when true
}

Project configuration recap

ExpandedLib.Testing.csproj: net10.0 by default (multi-targets net8.0/net7.0 with -p:Legacy=true), C# 14, nullable enabled. References NSubstitute 5.3.0 and the game DLLs (VintagestoryAPI, VSSurvivalMod, VSEssentials, 0Harmony, Newtonsoft.Json, all Private=false), and project-references ExpandedLib. A consuming test project additionally needs Microsoft.NET.Test.Sdk 17.12.0, xunit 2.9.2, xunit.runner.visualstudio 2.8.2, plus a reference to the mod under test.

Related pages

• Testing Harness — setup, module initializer, worked examples.
• Block Networks — the real types these doubles stand in for.