feat(siteruntime): thread ParentExecutionId into the routed script's ScriptRuntimeContext

tests/ScadaLink.SiteRuntime.Tests/Scripts/ExecutionCorrelationContextTests.cs

@@ -62,7 +62,8 @@ public class ExecutionCorrelationContextTests
         IExternalSystemClient? externalSystemClient,
         IDatabaseGateway? databaseGateway,
         IAuditWriter? auditWriter,
-        Guid? executionId = null)
+        Guid? executionId = null,
+        Guid? parentExecutionId = null)
     {
         var compilationService = new ScriptCompilationService(
             NullLogger<ScriptCompilationService>.Instance);
@@ -87,7 +88,24 @@ public class ExecutionCorrelationContextTests
             auditWriter: auditWriter,
             operationTrackingStore: null,
             cachedForwarder: null,
-            executionId: executionId);
+            executionId: executionId,
+            parentExecutionId: parentExecutionId);
+    }
+
+    /// <summary>
+    /// Reads a private <see cref="Guid"/>/<see cref="Nullable{Guid}"/> field off a
+    /// <see cref="ScriptRuntimeContext"/>. The ParentExecutionId plumbing (Audit
+    /// Log #23, Task 4) only stores the value on the context — no emitter stamps
+    /// it onto an audit row yet (that is Task 5) — so the field is inspected
+    /// directly rather than through an emitted row.
+    /// </summary>
+    private static object? ReadPrivateField(ScriptRuntimeContext context, string fieldName)
+    {
+        var field = typeof(ScriptRuntimeContext).GetField(
+            fieldName,
+            System.Reflection.BindingFlags.Instance | System.Reflection.BindingFlags.NonPublic);
+        Assert.NotNull(field);
+        return field!.GetValue(context);
     }
 
     /// <summary>
@@ -183,4 +201,54 @@ public class ExecutionCorrelationContextTests
         Assert.Null(apiRow.CorrelationId);
         Assert.Null(dbRow.CorrelationId);
     }
+
+    [Fact]
+    public void ParentExecutionIdSupplied_StoredVerbatim_AndOwnExecutionIdIsFreshAndDistinct()
+    {
+        // Audit Log #23 (ParentExecutionId, Task 4): an inbound-API-routed call
+        // supplies the spawning execution's ExecutionId as the routed script's
+        // ParentExecutionId. The context must store that value verbatim AND
+        // still mint its OWN fresh ExecutionId — the routed script is a new
+        // execution, it does not inherit the parent's id.
+        var parentExecutionId = Guid.NewGuid();
+
+        var context = CreateContext(
+            externalSystemClient: null,
+            databaseGateway: null,
+            auditWriter: null,
+            // executionId omitted — the ctor's `?? Guid.NewGuid()` fallback runs.
+            parentExecutionId: parentExecutionId);
+
+        var storedParent = ReadPrivateField(context, "_parentExecutionId");
+        var ownExecutionId = ReadPrivateField(context, "_executionId");
+
+        // The parent id is carried through untouched.
+        Assert.Equal(parentExecutionId, storedParent);
+
+        // The routed script's own ExecutionId is freshly generated, non-empty,
+        // and NOT the parent id — they are separate correlation values.
+        Assert.NotNull(ownExecutionId);
+        var ownId = Assert.IsType<Guid>(ownExecutionId);
+        Assert.NotEqual(Guid.Empty, ownId);
+        Assert.NotEqual(parentExecutionId, ownId);
+    }
+
+    [Fact]
+    public void NoParentExecutionIdSupplied_NonRoutedRun_ParentStaysNull()
+    {
+        // A normal (tag-change / timer) script run is not inbound-API-routed —
+        // no ParentExecutionId is supplied, so _parentExecutionId stays null
+        // while the run still gets its own fresh ExecutionId.
+        var context = CreateContext(
+            externalSystemClient: null,
+            databaseGateway: null,
+            auditWriter: null);
+
+        var storedParent = ReadPrivateField(context, "_parentExecutionId");
+        var ownExecutionId = ReadPrivateField(context, "_executionId");
+
+        Assert.Null(storedParent);
+        var ownId = Assert.IsType<Guid>(ownExecutionId);
+        Assert.NotEqual(Guid.Empty, ownId);
+    }
 }