test262/harness: impl native function matcher

test262: 55.51% (+0.11) | 🧪 48625 | 🤠 26991 (+54) | ❌ 7363 | 💀 12943 (-54) | 🏗️ 21 | 💥 165 | ⏰ 135 | 📝 1007

package.json

@@ -1,7 +1,7 @@
 {
   "name": "porffor",
   "description": "a basic experimental wip aot optimizing js -> wasm engine/compiler/runtime in js",
-  "version": "0.55.1",
+  "version": "0.55.2",
   "author": "CanadaHonk",
   "license": "MIT",
   "scripts": {},

runner/index.js

@@ -1,6 +1,6 @@
 #!/usr/bin/env node
 import fs from 'node:fs';
-globalThis.version = '0.55.1';
+globalThis.version = '0.55.2';
 
 // deno compat
 if (typeof process === 'undefined' && typeof Deno !== 'undefined') {

test262/harness.js

@@ -1361,4 +1361,25 @@ const asyncTest = testFunc => {
   }
 };
 
-// todo: assert.throwsAsync
+// todo: assert.throwsAsync
+
+/// nativeFunctionMatcher.js
+const validateNativeFunctionSource = source => source.startsWith('function ') && source.endsWith('() { [native code] }');
+
+const assertToStringOrNativeFunction = function(fn, expected) {
+  const actual = fn.toString();
+  try {
+    assert.sameValue(actual, expected);
+  } catch {
+    assertNativeFunction(fn, expected);
+  }
+};
+
+const assertNativeFunction = function(fn, special) {
+  const actual = fn.toString();
+  try {
+    validateNativeFunctionSource(actual);
+  } catch {
+    throw new Test262Error('assertNativeFunction failed');
+  }
+};