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CallbackSpy and CallLog

Tsvrc.UdonTestKit.CallbackSpy is a test spy for code that calls methods on an UdonSharpBehaviour by name, such as with SendCustomEvent. Tsvrc.UdonTestKit.CallLog creates spies and records every call they receive, in order, as "GameObjectName.CallbackName".

using var calls = new CallLog();
CallbackSpy listener = calls.CreateSpy("Listener");
scoreboard.Subscribe(listener, nameof(CallbackSpy.CallbackA));

scoreboard.AddPoint();

Assert.That(calls, Is.EqualTo(new[] { "Listener.CallbackA" }));

Both work in Edit Mode and Play Mode tests. Check the calls your code makes by name walks through it.

CallLog​

CallLog is an IReadOnlyList<string> of the calls so far, so NUnit constraints such as Is.EqualTo(new[] { ... }) and Has.Member(...) work on it directly. It's also IDisposable.

  • CreateSpy(string name = "Spy") creates a GameObject with that name in the active scene, adds a CallbackSpy to it, and returns the spy.
  • CreateSpy<TSpy>(string name) does the same with your own subclass of CallbackSpy.
  • Clear() forgets the calls recorded so far, such as the ones a test's setup caused. It doesn't destroy any spy.
  • Dispose() destroys the GameObject of every spy it created, skipping any already destroyed. using var calls = new CallLog(); is all the cleanup a test needs.

Spies created from the same log record into it in the order the calls arrive, so one assertion checks both how many calls each spy got and their order across spies.

CallbackSpy​

CallbackSpy is an UdonSharpBehaviour with two callbacks, CallbackA() and CallbackB(), which cover most tests. Each call is recorded under the spy's GameObject name at the time of the call.

For callbacks named after what your code calls, subclass it and call Record() from each method. Record takes the name of the method that called it:

public class DoorSpy : CallbackSpy
{
    public void Open() => Record();
    public void Close() => Record();
}

calls.CreateSpy<DoorSpy>("Door") then records "Door.Open" and "Door.Close".

Put subclasses in an assembly that compiles for every platform, such as the Doubles assembly TestAssemblyCreator creates. Unity won't add a behaviour from an Editor-only assembly to a GameObject, and an Edit Mode test assembly is Editor-only.

Calls by name outside Udon​

Tests run your UdonSharpBehaviours as plain C#, not as Udon. In that mode, SendCustomEvent calls a public method with no parameters and exactly the given name. Any other name does nothing and raises no error, so a misspelled callback name passes silently: check what the log recorded, not just that nothing failed.

SendCustomEventDelayedSeconds and SendCustomEventDelayedFrames don't call anything outside Udon. Code under test that relies on them needs its delayed method called directly from the test.

Failure modes​

  • A CallbackSpy that a CallLog didn't create throws InvalidOperationException on its first call, naming the spy and the callback. Add a spy with CreateSpy, not AddComponent.
  • Spies record names only, never arguments.