fix: test-shadow-realm-prepare-stack-trace

test/js/node/test/.gitignore

@@ -8,4 +8,5 @@ fixtures/repl*
 .tmp.*
 *shadow-realm*
 !test-shadow-realm.js
+!test-shadow-realm-prepare-stack-trace.js
 **/fails.txt

test/js/node/test/parallel/test-shadow-realm-prepare-stack-trace.js

@@ -0,0 +1,53 @@
+// Flags: --experimental-shadow-realm
+'use strict';
+
+require('../common');
+const assert = require('assert');
+
+let principalRealmPrepareStackTraceCalled = false;
+Error.prepareStackTrace = (error, trace) => {
+  principalRealmPrepareStackTraceCalled = true;
+  return `${String(error)}\n    at ${trace.join('\n    at ')}`;
+};
+
+{
+  // Validates inner Error.prepareStackTrace can not leak into the outer realm.
+  const shadowRealm = new ShadowRealm();
+
+  const stack = shadowRealm.evaluate(`
+Error.prepareStackTrace = (error, trace) => {
+  globalThis.leaked = 'inner';
+  return 'from shadow realm';
+};
+
+try {
+  throw new Error('boom');
+} catch (e) {
+  e.stack;
+}
+`);
+  assert.ok(!principalRealmPrepareStackTraceCalled);
+  assert.strictEqual(stack, 'from shadow realm');
+  assert.strictEqual('leaked' in globalThis, false);
+}
+
+{
+  // Validates stacks can be generated in the ShadowRealm.
+  const shadowRealm = new ShadowRealm();
+
+  const stack = shadowRealm.evaluate(`
+function myFunc() {
+  throw new Error('boom');
+}
+
+try {
+  myFunc();
+} catch (e) {
+  e.stack;
+}
+`);
+  assert.ok(!principalRealmPrepareStackTraceCalled);
+  const lines = stack.split('\n');
+  assert.strictEqual(lines[0], 'Error: boom');
+  assert.match(lines[1], /^ {4}at myFunc \(.*\)/);
+}