Fix scope for conditional resources (#2250)

src/Bicep.Core.IntegrationTests/ScenarioTests.cs

@@ -1538,10 +1538,31 @@ public void Variable_loops_should_not_cause_infinite_recursion()
   name: name
   value: 'prefix-${i}-${name}-suffix'
 }]
+");
+
+            result.Should().NotHaveDiagnostics();
+            result.Template.Should().NotBeNull();
+        }
+
+        [TestMethod]
+        public void Test_Issue1883()
+        {
+            var result = CompilationHelper.Compile(@"
+resource vm 'Microsoft.Compute/virtualMachines@2020-06-01' = if (true) {
+  name: 'myVM'
+  location: 'westus'
+  
+  resource vmExt 'extensions' = {
+    name: 'myVMExtension'
+    location: vm.location
+  }
+}
+
+output vmExtName string = vm::vmExt.name
 ");
 
             result.Should().NotHaveDiagnostics();
             result.Template.Should().NotBeNull();
         }
     }
-}
+}

src/Bicep.Core/Semantics/DeclarationVisitor.cs

@@ -61,7 +61,8 @@ public override void VisitResourceDeclarationSyntax(ResourceDeclarationSyntax sy
             // There may be additional scopes nested inside this between the resource declaration
             // and the actual object body (for-loop). That's OK, in that case, this scope will
             // be empty and we'll use the `for` scope for lookups.
-            var scope = new LocalScope(string.Empty, syntax, syntax.Value, ImmutableArray<DeclaredSymbol>.Empty, ImmutableArray<LocalScope>.Empty);
+            var bindingSyntax = syntax.Value is IfConditionSyntax ifConditionSyntax ? ifConditionSyntax.Body : syntax.Value;
+            var scope = new LocalScope(string.Empty, syntax, bindingSyntax, ImmutableArray<DeclaredSymbol>.Empty, ImmutableArray<LocalScope>.Empty);
             this.PushScope(scope);
 
             base.VisitResourceDeclarationSyntax(syntax);