test(core): cover typed side effect payloads

Author: rian-be

Tests/ModularityKit.Mutator.Tests/Effects/SideEffectTypedDataTests.cs

@@ -0,0 +1,90 @@
+using System.Text.Json;
+using ModularityKit.Mutator.Abstractions.Effects;
+using Xunit;
+
+namespace ModularityKit.Mutator.Tests.Effects;
+
+public sealed class SideEffectTypedDataTests
+{
+    [Fact]
+    public void Create_with_typed_payload_populates_contract_metadata()
+    {
+        var effect = SideEffect.Create(
+            type: "WorkflowStarted",
+            description: "Workflow started",
+            data: new WorkflowStartedSideEffectData
+            {
+                Initiator = "alice",
+                StepCount = 2,
+                WorkflowId = "wf-42"
+            });
+
+        Assert.Equal("workflow.started", effect.DataContractType);
+        Assert.Equal(1, effect.DataContractVersion);
+        Assert.True(effect.TryGetData<WorkflowStartedSideEffectData>(out var data));
+        Assert.Equal("wf-42", data!.WorkflowId);
+    }
+
+    [Fact]
+    public void Json_roundtrip_rehydrates_registered_typed_payload()
+    {
+        SideEffectDataContractRegistry.Register<WorkflowStartedSideEffectData>();
+
+        var effect = SideEffect.Create(
+            type: "WorkflowStarted",
+            description: "Workflow started",
+            data: new WorkflowStartedSideEffectData
+            {
+                Initiator = "alice",
+                StepCount = 2,
+                WorkflowId = "wf-42"
+            });
+
+        var roundtrip = JsonSerializer.Deserialize<SideEffect>(JsonSerializer.Serialize(effect));
+
+        Assert.NotNull(roundtrip);
+        Assert.Equal("workflow.started", roundtrip!.DataContractType);
+        Assert.True(roundtrip.TryGetData<WorkflowStartedSideEffectData>(out var data));
+        Assert.Equal("alice", data!.Initiator);
+        Assert.Equal(2, data.StepCount);
+    }
+
+    [Fact]
+    public void Json_roundtrip_without_registration_preserves_contract_and_payload_shape()
+    {
+        var effect = new SideEffect
+        {
+            Type = "WorkflowStarted",
+            Description = "Workflow started",
+            Data = new WorkflowStartedSideEffectData
+            {
+                Initiator = "alice",
+                StepCount = 2,
+                WorkflowId = "wf-42"
+            },
+            DataContractType = "workflow.started.unregistered",
+            DataContractVersion = 1
+        };
+
+        var roundtrip = JsonSerializer.Deserialize<SideEffect>(JsonSerializer.Serialize(effect));
+
+        Assert.NotNull(roundtrip);
+        Assert.Equal("workflow.started.unregistered", roundtrip!.DataContractType);
+        Assert.Equal(1, roundtrip.DataContractVersion);
+
+        var payload = Assert.IsAssignableFrom<IReadOnlyDictionary<string, object?>>(roundtrip.Data);
+        Assert.Equal("alice", payload["Initiator"]);
+        Assert.Equal(2L, payload["StepCount"]);
+        Assert.Equal("wf-42", payload["WorkflowId"]);
+    }
+
+    [SideEffectDataContract("workflow.started", 1)]
+    private sealed record WorkflowStartedSideEffectData
+    {
+        public required string Initiator { get; init; }
+
+        public required int StepCount { get; init; }
+
+        public required string WorkflowId { get; init; }
+    }
+}