1 files changed, 49 insertions, 0 deletions
diff --git a/js/src/tests/test262/built-ins/Iterator/prototype/flatMap/throws-typeerror-when-generator-is-running.js b/js/src/tests/test262/built-ins/Iterator/prototype/flatMap/throws-typeerror-when-generator-is-running.js
new file mode 100644
index 0000000000..2d404dd2e7
--- /dev/null
+++ b/js/src/tests/test262/built-ins/Iterator/prototype/flatMap/throws-typeerror-when-generator-is-running.js
@@ -0,0 +1,49 @@
+// |reftest| shell-option(--enable-iterator-helpers) skip-if(!this.hasOwnProperty('Iterator')||!xulRuntime.shell) -- iterator-helpers is not enabled unconditionally, requires shell-options
+// Copyright (C) 2023 André Bargull. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-iteratorprototype.flatmap
+description: >
+  Throws a TypeError when the closure generator is already running.
+info: |
+  %IteratorHelperPrototype%.next ( )
+    1. Return ? GeneratorResume(this value, undefined, "Iterator Helper").
+
+  27.5.3.3 GeneratorResume ( generator, value, generatorBrand )
+    1. Let state be ? GeneratorValidate(generator, generatorBrand).
+    ...
+
+  27.5.3.2 GeneratorValidate ( generator, generatorBrand )
+    ...
+    6. If state is executing, throw a TypeError exception.
+    ...
+
+features: [iterator-helpers]
+---*/
+
+var loopCount = 0;
+
+function* g() {
+  while (true) {
+    loopCount++;
+    yield;
+  }
+}
+
+var enterCount = 0;
+
+function mapper() {
+  enterCount++;
+  iter.next();
+}
+
+var iter = g().flatMap(mapper);
+
+assert.throws(TypeError, function() {
+  iter.next();
+});
+
+assert.sameValue(loopCount, 1);
+assert.sameValue(enterCount, 1);
+
+reportCompare(0, 0);