meeting-assistant/MeetingAssistant.Tests/SpeakerIdentityMergerTests.cs

using MeetingAssistant.Speakers;

namespace MeetingAssistant.Tests;

public sealed class SpeakerIdentityMergerTests
{
    [Fact]
    public void MergeIntoRetainsNewestDistinctVoiceVectorsUpToConfiguredLimit()
    {
        var now = DateTimeOffset.UtcNow;
        var target = new SpeakerIdentity
        {
            CanonicalName = "Chris",
            VoiceVectors =
            [
                Vector("oldest", 1, now.AddMinutes(-4)),
                Vector("duplicate", 2, now.AddMinutes(-3))
            ]
        };
        var source = new SpeakerIdentity
        {
            VoiceVectors =
            [
                Vector("duplicate", 2, now.AddMinutes(-2)),
                Vector("newer", 3, now.AddMinutes(-1)),
                Vector("newest", 4, now)
            ]
        };

        SpeakerIdentityMerger.MergeInto(target, source, maxSnippets: 3, maxVoiceVectors: 3);

        Assert.Equal(["duplicate", "newer", "newest"], target.VoiceVectors.Select(vector => vector.Fingerprint).Order());
        Assert.All(target.VoiceVectors, vector => Assert.Same(target, vector.SpeakerIdentity));
    }

    private static SpeakerVoiceVector Vector(string fingerprint, byte value, DateTimeOffset createdAt)
    {
        return new SpeakerVoiceVector
        {
            ModelId = "model",
            Dimensions = 256,
            VectorBytes = Enumerable.Repeat(value, 256 * sizeof(float)).ToArray(),
            Fingerprint = fingerprint,
            CreatedAt = createdAt
        };
    }
}