add test for relative-indexing-method proposal and enable test262 tests

Author: wirthi

graal-js/src/com.oracle.truffle.js.test.external/src/com/oracle/truffle/js/test/external/test262/Test262Runnable.java

@@ -89,6 +89,7 @@ public class Test262Runnable extends TestRunnable {
 
     private static final Set<String> SUPPORTED_FEATURES = new HashSet<>(Arrays.asList(new String[]{
                     "AggregateError",
+                    "Array.prototype.at",
                     "Array.prototype.flat",
                     "Array.prototype.flatMap",
                     "Array.prototype.values",
@@ -133,6 +134,7 @@ public class Test262Runnable extends TestRunnable {
                     "Set",
                     "SharedArrayBuffer",
                     "String.fromCodePoint",
+                    "String.prototype.at",
                     "String.prototype.endsWith",
                     "String.prototype.includes",
                     "String.prototype.matchAll",
@@ -155,6 +157,7 @@ public class Test262Runnable extends TestRunnable {
                     "Symbol.toStringTag",
                     "Symbol.unscopables",
                     "TypedArray",
+                    "TypedArray.prototype.at",
                     "Uint16Array",
                     "Uint32Array",
                     "Uint8Array",
@@ -220,19 +223,19 @@ public class Test262Runnable extends TestRunnable {
                     "top-level-await",
     }));
     private static final Set<String> UNSUPPORTED_FEATURES = new HashSet<>(Arrays.asList(new String[]{
-                    "Array.prototype.at",
                     "Atomics.waitAsync",
                     "Intl.DateTimeFormat-dayPeriod",
                     "Intl.DateTimeFormat-formatRange",
                     "Intl.DateTimeFormat-fractionalSecondDigits",
                     "IsHTMLDDA",
-                    "String.prototype.at",
-                    "TypedArray.prototype.at",
                     "align-detached-buffer-semantics-with-web-reality",
                     "arbitrary-module-namespace-names",
                     "tail-call-optimization",
     }));
     private static final Set<String> ES2022_FEATURES = new HashSet<>(Arrays.asList(new String[]{
+                    "Array.prototype.at",
+                    "String.prototype.at",
+                    "TypedArray.prototype.at",
                     "class-fields-private",
                     "class-fields-public",
                     "class-methods-private",

graal-js/src/com.oracle.truffle.js.test/js/runtime/relativeIndexingProposal.js

@@ -0,0 +1,79 @@
+/*
+ * Copyright (c) 2020, 2020, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * Licensed under the Universal Permissive License v 1.0 as shown at http://oss.oracle.com/licenses/upl.
+ */
+/**
+ * Test for the relative-indexing-method proposal.
+ * https://tc39.es/proposal-relative-indexing-method/
+ * 
+ * @option ecmascript-version=2022
+ */
+
+load('../assert.js');
+
+function arrayPrototypeTest() {
+  var arr = [0,1,2,3,4,5];
+
+  //in bound
+  assertSame(0, arr.at(0));
+  assertSame(1, arr.at(1));
+  assertSame(5, arr.at(5));
+
+  //out of bound
+  assertSame(undefined, arr.at(6));
+  assertSame(5, arr.at(-1));
+  assertSame(4, arr.at(-2));
+  
+  //general
+  assertSame(1, Array.prototype.at.length);
+}
+
+function stringPrototypeTest() {
+  var str = "Graal.js";
+
+  //in bound
+  assertSame("G", str.at(0));
+  assertSame("r", str.at(1));
+  assertSame("s", str.at(7));
+
+  //out of bound
+  assertSame(undefined, str.at(100));
+  assertSame("s", str.at(-1));
+  assertSame("j", str.at(-2));
+
+  //general
+  assertSame(1, String.prototype.at.length);
+}
+
+function typedArrayPrototypeTestIntl(constr) {
+  var arr = new constr([0,1,2,3,4,5]);
+
+  //in bound
+  assertSame(0, arr.at(0));
+  assertSame(1, arr.at(1));
+  assertSame(5, arr.at(5));
+
+  //out of bound
+  assertSame(undefined, arr.at(100));
+  assertSame(5, arr.at(-1));
+  assertSame(4, arr.at(-2));
+
+  //general
+  assertSame(1, constr.prototype.at.length);
+}
+
+function typedArrayPrototypeTest() {
+  var types = [Int8Array, Uint8Array, Uint8ClampedArray, Int16Array, Uint16Array, Int32Array,
+               Uint32Array, Float32Array, Float64Array];
+  types.forEach( constr => {
+    typedArrayPrototypeTestIntl(constr);
+  });
+}
+
+arrayPrototypeTest();
+stringPrototypeTest();
+typedArrayPrototypeTest();
+
+true;