1 files changed, 58 insertions, 0 deletions
diff --git a/js/src/tests/non262/String/ropes.js b/js/src/tests/non262/String/ropes.js
new file mode 100644
index 0000000000..b8e99dacb9
--- /dev/null
+++ b/js/src/tests/non262/String/ropes.js
@@ -0,0 +1,58 @@
+print("Stress test of ropes");
+
+if (typeof newRope === "undefined") {
+    var newRope = SpecialPowers.Cu.getJSTestingFunctions().newRope;
+}
+if (typeof ensureLinearString === "undefined") {
+    var ensureLinearString = SpecialPowers.Cu.getJSTestingFunctions().ensureLinearString;
+}
+
+function createRopes() {
+    const ropes = {};
+
+    let j = 88;
+    function advance() {
+        // This is totally made up and probably stupid.
+        j = ((((j * 7) >> 2) + j) + (j << 3)) | 0;
+        return j;
+    }
+
+    function randomBalancedRope(height) {
+        if (height == 0)
+            return "s" + j;
+
+        const left = randomBalancedRope(height - 1);
+        advance();
+        const right = randomBalancedRope(height - 1);
+        advance();
+        return newRope(left, right, {nursery:(j & 1)});
+    }
+
+    // Construct a fairly big random rope first. If we did it later, then the
+    // chances of it all ending up tenured are higher.
+    ropes.balanced = randomBalancedRope(10);
+
+    ropes.simple = newRope("a", "b");
+    ropes.simple_tenured = newRope("a", "b", {nursery:false});
+    ropes.tenured_nursery = newRope("a", newRope("b", "c", {nursery:true}), {nursery:false});
+    ropes.nursery_tenured = newRope("a", newRope("b", "c", {nursery:false}), {nursery:true});
+
+    return ropes;
+}
+
+const ropes = createRopes();
+
+// Flatten them all.
+for (const [name, rope] of Object.entries(ropes))
+    ensureLinearString(rope);
+
+// GC with them all live.
+let ropes2 = createRopes();
+gc();
+
+// GC with them all dead.
+ropes2 = null;
+gc();
+
+if (typeof reportCompare === "function")
+    reportCompare(true, true);