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-rw-r--r--js/src/tests/non262/expressions/short-circuit-compound-assignment-property-key-evaluation.js68
1 files changed, 68 insertions, 0 deletions
diff --git a/js/src/tests/non262/expressions/short-circuit-compound-assignment-property-key-evaluation.js b/js/src/tests/non262/expressions/short-circuit-compound-assignment-property-key-evaluation.js
new file mode 100644
index 0000000000..2026aa25d1
--- /dev/null
+++ b/js/src/tests/non262/expressions/short-circuit-compound-assignment-property-key-evaluation.js
@@ -0,0 +1,68 @@
+// Test that property keys are only evaluated once.
+
+class PropertyKey {
+ constructor(key) {
+ this.key = key;
+ this.count = 0;
+ }
+
+ toString() {
+ this.count++;
+ return this.key;
+ }
+
+ valueOf() {
+ throw new Error("unexpected valueOf call");
+ }
+}
+
+// AndAssignExpr
+{
+ let obj = {p: true};
+ let pk = new PropertyKey("p");
+
+ obj[pk] &&= false;
+
+ assertEq(obj.p, false);
+ assertEq(pk.count, 1);
+
+ obj[pk] &&= true;
+
+ assertEq(obj.p, false);
+ assertEq(pk.count, 2);
+}
+
+// OrAssignExpr
+{
+ let obj = {p: false};
+ let pk = new PropertyKey("p");
+
+ obj[pk] ||= true;
+
+ assertEq(obj.p, true);
+ assertEq(pk.count, 1);
+
+ obj[pk] ||= false;
+
+ assertEq(obj.p, true);
+ assertEq(pk.count, 2);
+}
+
+// CoalesceAssignExpr
+{
+ let obj = {p: null};
+ let pk = new PropertyKey("p");
+
+ obj[pk] ??= true;
+
+ assertEq(obj.p, true);
+ assertEq(pk.count, 1);
+
+ obj[pk] ??= false;
+
+ assertEq(obj.p, true);
+ assertEq(pk.count, 2);
+}
+
+if (typeof reportCompare === "function")
+ reportCompare(0, 0);