1 files changed, 22 insertions, 0 deletions
diff --git a/js/src/tests/non262/Iterator/from/modify-return.js b/js/src/tests/non262/Iterator/from/modify-return.js
new file mode 100644
index 0000000000..733eec69d7
--- /dev/null
+++ b/js/src/tests/non262/Iterator/from/modify-return.js
@@ -0,0 +1,22 @@
+// |reftest| skip-if(!this.hasOwnProperty('Iterator')) -- Iterator is not enabled unconditionally
+const iter = {
+  next: () => ({ done: false, value: 0 }),
+  return: (value) => ({ done: true, value }),
+};
+
+const wrap = Iterator.from(iter);
+
+let {done, value} = wrap.return(1);
+assertEq(done, true);
+assertEq(value, 1);
+
+iter.return = () => { throw new Error(); };
+assertThrowsInstanceOf(wrap.return, Error);
+
+iter.return = null;
+let nullResult = wrap.return(2);
+assertEq(nullResult.done, true);
+assertEq(nullResult.value, 2);
+
+if (typeof reportCompare === 'function')
+  reportCompare(0, 0);