Update Test262 tests

third_party/test262/harness/assert.js

@@ -3,10 +3,52 @@
 /*---
 description: |
     Collection of assertion functions used throughout test262
-defines: [assert]
+defines:
+  - assert
+  - formatIdentityFreeValue
+  - formatSimpleValue
+  - isNegativeZero
+  - isPrimitive
 ---*/
 
 
+function isNegativeZero(value) {
+  return value === 0 && 1 / value === -Infinity;
+}
+
+function isPrimitive(value) {
+  return !value || (typeof value !== 'object' && typeof value !== 'function');
+}
+
+function formatIdentityFreeValue(value) {
+  switch (value === null ? 'null' : typeof value) {
+    case 'string':
+      return typeof JSON !== "undefined" ? JSON.stringify(value) : '"' + value + '"';
+    case 'bigint':
+      return String(value) + "n";
+    case 'number':
+      if (isNegativeZero(value)) return '-0';
+      // falls through
+    case 'boolean':
+    case 'undefined':
+    case 'null':
+      return String(value);
+  }
+}
+
+function formatSimpleValue(value) {
+  var basic = formatIdentityFreeValue(value);
+  if (basic) return basic;
+  try {
+    return String(value);
+  } catch (err) {
+    if (err.name === 'TypeError') {
+      return Object.prototype.toString.call(value);
+    }
+    throw err;
+  }
+}
+
 function assert(mustBeTrue, message) {
   if (mustBeTrue === true) {
     return;
@@ -101,10 +143,6 @@ assert.throws = function (expectedErrorConstructor, func, message) {
   throw new Test262Error(message);
 };
 
-function isPrimitive(value) {
-  return !value || (typeof value !== 'object' && typeof value !== 'function');
-}
-
 assert.compareArray = function (actual, expected, message) {
   message = message === undefined ? '' : message;
 
@@ -113,15 +151,15 @@ assert.compareArray = function (actual, expected, message) {
   }
 
   if (isPrimitive(actual)) {
-    assert(false, `Actual argument [${actual}] shouldn't be primitive. ${message}`);
+    assert(false, "Actual argument [" + actual + "] shouldn't be primitive. " + String(message));
   } else if (isPrimitive(expected)) {
-    assert(false, `Expected argument [${expected}] shouldn't be primitive. ${message}`);
+    assert(false, "Expected argument [" + expected + "] shouldn't be primitive. " + String(message));
   }
   var result = compareArray(actual, expected);
   if (result) return;
 
   var format = compareArray.format;
-  assert(false, `Actual ${format(actual)} and expected ${format(expected)} should have the same contents. ${message}`);
+  assert(false, "Actual " + format(actual) + " and expected " + format(expected) + " should have the same contents. " + String(message));
 };
 
 function compareArray(a, b) {
@@ -137,34 +175,9 @@ function compareArray(a, b) {
 }
 
 compareArray.format = function (arrayLike) {
-  return `[${Array.prototype.map.call(arrayLike, String).join(', ')}]`;
+  return "[" + Array.prototype.map.call(arrayLike, String).join(", ") + "]";
 };
 
-assert._formatIdentityFreeValue = function formatIdentityFreeValue(value) {
-  switch (value === null ? 'null' : typeof value) {
-    case 'string':
-      return typeof JSON !== "undefined" ? JSON.stringify(value) : `"${value}"`;
-    case 'bigint':
-      return `${value}n`;
-    case 'number':
-      if (value === 0 && 1 / value === -Infinity) return '-0';
-      // falls through
-    case 'boolean':
-    case 'undefined':
-    case 'null':
-      return String(value);
-  }
-};
+assert._formatIdentityFreeValue = formatIdentityFreeValue;
 
-assert._toString = function (value) {
-  var basic = assert._formatIdentityFreeValue(value);
-  if (basic) return basic;
-  try {
-    return String(value);
-  } catch (err) {
-    if (err.name === 'TypeError') {
-      return Object.prototype.toString.call(value);
-    }
-    throw err;
-  }
-};
+assert._toString = formatSimpleValue;

third_party/test262/harness/asyncHelpers.js

@@ -8,7 +8,7 @@ defines: [asyncTest, assert.throwsAsync]
 
 /**
  * Defines the **sole** asynchronous test of a file.
- * @see {@link ../docs/rfcs/async-helpers.md} for background.
+ * @see {@link ../rfcs/async-helpers.md} for background.
  *
  * @param {Function} testFunc a callback whose returned promise indicates test results
  *   (fulfillment for success, rejection for failure)

third_party/test262/harness/nativeErrors.js

@@ -0,0 +1,52 @@
+// Copyright (C) 2026 Jordan Harband. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+description: |
+    Arrays of language-specified Error constructors, plus a helper that
+    constructs a sample instance with appropriate arguments for the
+    constructor's signature.
+
+    `nativeErrors` contains every Error constructor whose first argument
+    is a `message` string: %Error% and the six NativeErrors.
+
+    `allErrorConstructors` additionally includes %AggregateError% and
+    %SuppressedError% when present in the host. Their constructors have
+    different signatures (`(errors, message)` and
+    `(error, suppressed, message)` respectively), so tests that just
+    iterate as `new Ctor(message)` should prefer `nativeErrors`; tests
+    that need to cover every Error-like constructor should use
+    `allErrorConstructors` together with `makeNativeError`.
+defines: [nativeErrors, allErrorConstructors, makeNativeError]
+---*/
+
+var nativeErrors = [
+  Error,
+  EvalError,
+  RangeError,
+  ReferenceError,
+  SyntaxError,
+  TypeError,
+  URIError
+];
+
+var allErrorConstructors = nativeErrors.slice();
+if (typeof AggregateError !== 'undefined') {
+  allErrorConstructors.push(AggregateError);
+}
+if (typeof SuppressedError !== 'undefined') {
+  allErrorConstructors.push(SuppressedError);
+}
+
+function makeNativeError(Ctor, useNew) {
+  if (typeof AggregateError !== 'undefined' && Ctor === AggregateError) {
+    return useNew
+      ? new AggregateError([new Error('inner')], 'msg')
+      : AggregateError([new Error('inner')], 'msg');
+  }
+  if (typeof SuppressedError !== 'undefined' && Ctor === SuppressedError) {
+    return useNew
+      ? new SuppressedError(new Error('inner'), new Error('suppressed'), 'msg')
+      : SuppressedError(new Error('inner'), new Error('suppressed'), 'msg');
+  }
+  return useNew ? new Ctor('msg') : Ctor('msg');
+}