1 files changed, 42 insertions, 0 deletions
diff --git a/js/src/jit-test/tests/saved-stacks/max-frame-count.js b/js/src/jit-test/tests/saved-stacks/max-frame-count.js
new file mode 100644
index 0000000000..17c3751765
--- /dev/null
+++ b/js/src/jit-test/tests/saved-stacks/max-frame-count.js
@@ -0,0 +1,42 @@
+// Test that we can capture only the N newest frames.
+// This is the maxFrameCount argument to JS::CaptureCurrentStack.
+
+load(libdir + 'asserts.js');
+
+function recur(n, limit) {
+  if (n > 0)
+    return recur(n - 1, limit);
+  return saveStack(limit);
+}
+
+// Negative values are rejected.
+assertThrowsInstanceOf(() => saveStack(-1), TypeError);
+
+// Zero means 'no limit'.
+assertEq(saveStack(0).parent, null);
+assertEq(recur(0, 0).parent !== null, true);
+assertEq(recur(0, 0).parent.parent, null);
+assertEq(recur(1, 0).parent.parent.parent, null);
+assertEq(recur(2, 0).parent.parent.parent.parent, null);
+assertEq(recur(3, 0).parent.parent.parent.parent.parent, null);
+
+// limit of 1
+assertEq(saveStack(1).parent, null);
+assertEq(recur(0, 1).parent, null);
+assertEq(recur(0, 1).parent, null);
+assertEq(recur(1, 1).parent, null);
+assertEq(recur(2, 1).parent, null);
+
+// limit of 2
+assertEq(saveStack(2).parent, null);
+assertEq(recur(0, 2).parent !== null, true);
+assertEq(recur(0, 2).parent.parent, null);
+assertEq(recur(1, 2).parent.parent, null);
+assertEq(recur(2, 2).parent.parent, null);
+
+// limit of 3
+assertEq(saveStack(3).parent, null);
+assertEq(recur(0, 3).parent !== null, true);
+assertEq(recur(0, 3).parent.parent, null);
+assertEq(recur(1, 3).parent.parent.parent, null);
+assertEq(recur(2, 3).parent.parent.parent, null);