delete of nonconfigurable indexed property should throw in strict mode

Irina Yatsenko · Irina Yatsenko · commit 177ee99ad45c · 2018-03-07T10:45:33.000-08:00
(tested with TypedArray)
diff --git a/lib/Runtime/Language/JavascriptOperators.cpp b/lib/Runtime/Language/JavascriptOperators.cpp
@@ -4818,6 +4818,11 @@ namespace Js
 #endif
         }
 
+        if (result == FALSE && (propertyOperationFlags & PropertyOperation_StrictMode))
+        {
+            JavascriptError::ThrowCantDelete(propertyOperationFlags, scriptContext, GetPropertyDisplayNameForError(index, scriptContext)->GetString());
+        }
+
         return scriptContext->GetLibrary()->CreateBoolean(result);
     }
 
diff --git a/test/typedarray/delete.js b/test/typedarray/delete.js
@@ -0,0 +1,50 @@
+//-------------------------------------------------------------------------------------------------------
+// Copyright (C) Microsoft. All rights reserved.
+// Licensed under the MIT license. See LICENSE.txt file in the project root for full license information.
+//-------------------------------------------------------------------------------------------------------
+
+if (this.WScript && this.WScript.LoadScriptFile) { // Check for running in ch
+    this.WScript.LoadScriptFile("..\\UnitTestFramework\\UnitTestFramework.js");
+    this.WScript.LoadScriptFile("util.js");
+}
+
+var tests = [
+    {
+        name: "Typed arrays support delete of non-indexed properties",
+        body: function () {
+            const ta = Int8Array.of(42);
+
+            ta.non_indexed = 'whatever';
+            assert.areEqual('whatever', ta.non_indexed, "ta.non_indexed is set to 'whatever'");
+
+            delete ta.non_indexed;
+            assert.areEqual(undefined, ta.non_indexed, "ta.non_indexed has been deleted");
+        }
+    },
+    {
+        name: "delete of nonconfigurable non-indexed properties on Typed arrays",
+        body: function () {
+            const ta = Int8Array.of(42);
+            var id = 'id';
+            Object.defineProperty(ta, id, { value: 17, configurable: false });
+
+            delete ta[id];
+            assert.areEqual(17, ta[id], "ta['id'] value after failed delete");
+
+            assert.throws(function () { 'use strict'; delete ta[id]; }, TypeError, "Should throw on delete of indexed property in typed array", "Calling delete on 'id' is not allowed in strict mode");
+        }
+    },
+    {
+        name: "Typed arrays don't support delete of indexed properties",
+        body: function () {
+            const ta = Int8Array.of(42);
+
+            delete ta[0];
+            assert.areEqual(42, ta[0], "ta[0] value after failed delete");
+
+            assert.throws(function () { 'use strict'; delete ta[0]; }, TypeError, "Should throw on delete of indexed property in typed array", "Calling delete on '0' is not allowed in strict mode");
+        }
+    }
+];
+
+testRunner.runTests(tests, { verbose: false /*so no need to provide baseline*/ });
diff --git a/test/typedarray/rlexe.xml b/test/typedarray/rlexe.xml
@@ -387,4 +387,10 @@ Below test fails with difference in space. Investigate the cause and re-enable t
       <tags>typedarray</tags>
     </default>
   </test>
+  <test>
+    <default>
+      <files>delete.js</files>
+      <tags>typedarray</tags>
+    </default>
+  </test>
 </regress-exe>

Original file line number	Diff line number	Diff line change
`@@ -4818,6 +4818,11 @@ namespace Js`
`4818`	`4818`	`#endif`
`4819`	`4819`	`}`
`4820`	`4820`
	`4821`	`+ if (result == FALSE && (propertyOperationFlags & PropertyOperation_StrictMode))`
	`4822`	`+ {`
	`4823`	`+ JavascriptError::ThrowCantDelete(propertyOperationFlags, scriptContext, GetPropertyDisplayNameForError(index, scriptContext)->GetString());`
	`4824`	`+ }`
	`4825`	`+`
`4821`	`4826`	`return scriptContext->GetLibrary()->CreateBoolean(result);`
`4822`	`4827`	`}`
`4823`	`4828`