Admit typeof unresolved identifiers

docs/unified-bytecode-expansion-contract.md

@@ -329,7 +329,7 @@ must still obey the no-mixed-execution rule.
 | `ArrowLexicalThisDependency` | Activation descriptor gate for arrow lexical `this` / `new.target` ownership before ordinary sync routing | Existing arrow invocation route | Arrow route lane | `rtk dotnet test tests/Asynkron.JsEngine.Tests --filter "FullyQualifiedName~UnifiedBytecodeProductionEligibilityTests&FullyQualifiedName~Evaluate_OrdinarySyncActivationDescriptorBlockers_DeclineBeforeCompile"` |
 | `ClassConstructorActivation` | Activation descriptor gate for class constructor activation outside the admitted simple base constructor route and explicit derived-constructor `super(...)` route with post-super `this` body reads/writes | Constructor route | Constructor boundary lane | `rtk dotnet test tests/Asynkron.JsEngine.Tests --filter "FullyQualifiedName~UnifiedBytecodeProductionConstructCallTests&FullyQualifiedName~Constructor"` |
 | `CallDependency` | Direct eval outside the one-argument non-spread eval-identifier boundary, out-of-boundary call-target preparation, complex call arguments excluding admitted simple/binary template-literal substitutions, simple/binary computed object keys, and zero-argument activation-resolved identifier-call computed object keys, and descriptor-level non-parameter callee calls | Existing sync IR call route | Wider call invocation lane | `rtk dotnet test tests/Asynkron.JsEngine.Tests --filter "FullyQualifiedName~UnifiedBytecodeProductionEligibilityTests&FullyQualifiedName~Evaluate_ActivationDependencies_DeclineBeforeCompile"` |
-| `DynamicLookupDependency` | Unresolved identifier loads/stores/typeof/update outside the with-backed dynamic-name path | Existing sync IR / environment lookup route | Dynamic-name lane | `rtk dotnet test tests/Asynkron.JsEngine.Tests --filter "FullyQualifiedName~UnifiedBytecodeProductionEligibilityTests&FullyQualifiedName~Evaluate_DynamicIdentifierLookup_DeclinesWithDynamicLookupDependency"` |
+| `DynamicLookupDependency` | Unresolved identifier loads/stores/update outside the admitted ordinary and with-backed dynamic-name paths | Existing sync IR / environment lookup route | Dynamic-name lane | `rtk dotnet test tests/Asynkron.JsEngine.Tests --filter "FullyQualifiedName~UnifiedBytecodeProductionEligibilityTests&FullyQualifiedName~Evaluate_DynamicIdentifierLookup_DeclinesWithDynamicLookupDependency"` |
 | `PropertyReadBoundaryOutOfScope` | Named/computed property reads outside the admitted activation-resolved boundaries | Existing sync IR property route | Property read widening lane | `rtk dotnet test tests/Asynkron.JsEngine.Tests --filter "FullyQualifiedName~UnifiedBytecodeProductionEligibilityTests&FullyQualifiedName~Evaluate_ComputedPropertyReadOutsideFirstBoundary_DeclinesWithBoundaryCode"` |
 | `PropertyWriteDependency` | Property writes and compound/logical property writes outside the admitted direct property-write shapes, supported computed expression-key mutation shapes, simple nested named receiver assignment shape, nested named compound-write shape, and nested named logical-write shape | Existing sync IR property-write route | Property write widening lane | `rtk dotnet test tests/Asynkron.JsEngine.Tests --filter "FullyQualifiedName~UnifiedBytecodeProductionEligibilityTests&FullyQualifiedName~Evaluate_LogicalAndAssignment_UnsupportedShapes_DeclineWithExplicitCodes"` |
 | `PropertyUpdateDependency` | Property and identifier update expressions outside the admitted direct update, computed expression-key update, and simple nested named receiver update boundary | Existing sync IR update route | Property update lane | `rtk dotnet test tests/Asynkron.JsEngine.Tests --filter "FullyQualifiedName~UnifiedBytecodeProductionEligibilityTests&FullyQualifiedName~Evaluate_NestedNamedPropertyUpdate_AcceptsOwnedPropertyOpcodes"` |
@@ -837,10 +837,11 @@ support today.
    or descriptor-backed assignment lanes remain outside the admitted boundary
    (`DestructuringDependency`).
 6. Dynamic lookup families remain outside the admitted boundary
-   (`DynamicLookupDependency`) except for the explicit with-backed dynamic name
-   slice above. Direct eval outside the admitted one-argument non-spread
-   eval-identifier boundary, unresolved non-with lookup shapes, and captured
-   dynamic activation still decline before VM execution.
+   (`DynamicLookupDependency`) except for the ordinary dynamic-name environment
+   path and the explicit with-backed dynamic name slice above. Direct eval
+   outside the admitted one-argument non-spread eval-identifier boundary,
+   unresolved dynamic activation, and unsupported unresolved lookup shapes still
+   decline before VM execution.
 7. Label-dependent control flow is now admitted (ADR 0285): labeled statements,
    labeled loops, labeled block `break`, and labeled `break`/`continue` route
    through the compiler-owned resolved-target path. The remaining

tests/Asynkron.JsEngine.Tests/UnifiedBytecodeProductionEligibilityTests.cs

@@ -4338,7 +4338,7 @@ function kind(value) {
     }
 
     [Fact]
-    public void Evaluate_TypeOfUnresolvedIdentifier_DeclinesWithDynamicLookupDependency()
+    public void Evaluate_TypeOfUnresolvedIdentifier_AcceptsOrdinaryDynamicNameOpcode()
     {
         var plan = GetFunctionPlan("""
             function kind() {
@@ -4349,11 +4349,13 @@ function kind() {
 
         var result = UnifiedBytecodeProductionEligibility.Evaluate(
             plan,
-            new UnifiedBytecodeProductionActivationDescriptor());
+            new UnifiedBytecodeProductionActivationDescriptor(
+                AllowsOrdinaryDynamicIdentifierEnvironmentOperations: true));
 
-        Assert.False(result.IsEligible);
-        Assert.Equal(UnifiedBytecodeProductionDeclineCode.DynamicLookupDependency, result.Code);
-        Assert.Contains("typeof identifier 'missing'", result.Reason, StringComparison.Ordinal);
+        Assert.True(result.IsEligible, result.Reason);
+        Assert.Equal(UnifiedBytecodeProductionDeclineCode.None, result.Code);
+        Assert.Contains(result.Program.Instructions, instruction =>
+            instruction.OpCode == UnifiedBytecodeOpCode.TypeOfDynamicIdentifier);
     }
 
     [Fact]

tests/Asynkron.JsEngine.Tests/UnifiedBytecodeProductionInvocationTests.cs

@@ -3144,6 +3144,25 @@ static record => record.Message.Contains(
                 StringComparison.Ordinal));
     }
 
+    [Fact(Timeout = 5000)]
+    public async Task TypeOfUnresolvedIdentifier_UsesUnifiedBytecodeProductionFastPath()
+    {
+        await using var engine = CreateEngine();
+        var result = await engine.Evaluate("""
+            function kind() {
+                return typeof missing;
+            }
+
+            kind();
+            """);
+
+        Assert.Equal("undefined", result?.ToString());
+        Assert.Contains(CurrentLogger!.Collector.Snapshot(),
+            static record => record.Message.Contains(
+                "unified-bytecode-production-fast-path func=kind argc=0",
+                StringComparison.Ordinal));
+    }
+
     [Fact(Timeout = 5000)]
     public async Task TypeOfIdentifierForLexicalTdz_PropagatesReferenceErrorThroughUnifiedBytecodeProductionFastPath()
     {