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diff --git a/js/src/jit-test/tests/for-of/semantics-09.js b/js/src/jit-test/tests/for-of/semantics-09.js
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+++ b/js/src/jit-test/tests/for-of/semantics-09.js
@@ -0,0 +1,25 @@
+// The LHS of a for-of loop is not evaluated until after the .next() method returns.
+
+var s;
+function f() {
+ s += 'f';
+ return {};
+}
+
+// Test 1: .next() throws StopIteration right away. f is never called.
+s = '';
+for (f().x of [])
+ s += '.';
+assertEq(s, '');
+
+// Test 2: check proper interleaving of f calls, iterator.next() calls, and the loop body.
+function g() {
+ s += 'g';
+ yield 0;
+ s += 'g';
+ yield 1;
+ s += 'g';
+}
+for (f().x of g())
+ s += '.';
+assertEq(s, 'gf.gf.g');