1 files changed, 24 insertions, 0 deletions
diff --git a/js/src/jit-test/tests/debug/Memory-drainAllocationsLog-03.js b/js/src/jit-test/tests/debug/Memory-drainAllocationsLog-03.js
new file mode 100644
index 000000000..064aed5cb
--- /dev/null
+++ b/js/src/jit-test/tests/debug/Memory-drainAllocationsLog-03.js
@@ -0,0 +1,24 @@
+// Test when there are more allocations than the maximum log length.
+
+const root = newGlobal();
+const dbg = new Debugger();
+dbg.addDebuggee(root)
+
+dbg.memory.maxAllocationsLogLength = 3;
+dbg.memory.trackingAllocationSites = true;
+
+root.eval([
+  "this.alloc1 = {};", // line 1
+  "this.alloc2 = {};", // line 2
+  "this.alloc3 = {};", // line 3
+  "this.alloc4 = {};", // line 4
+].join("\n"));
+
+const allocs = dbg.memory.drainAllocationsLog();
+
+// Should have stayed at the maximum length.
+assertEq(allocs.length, 3);
+// Should have kept the most recent allocation.
+assertEq(allocs[2].frame.line, 4);
+// Should have thrown away the oldest allocation.
+assertEq(allocs.map(x => x.frame.line).indexOf(1), -1);