1 files changed, 35 insertions, 0 deletions
diff --git a/js/src/jit-test/tests/debug/Frame-onStep-generators-defaults.js b/js/src/jit-test/tests/debug/Frame-onStep-generators-defaults.js
new file mode 100644
index 0000000000..ea32cc0094
--- /dev/null
+++ b/js/src/jit-test/tests/debug/Frame-onStep-generators-defaults.js
@@ -0,0 +1,35 @@
+// onStep works during the evaluation of default parameter values in generators.
+//
+// (They're evaluated at a weird time in the generator life cycle, before the
+// generator object is created.)
+
+load(libdir + "asserts.js");
+
+let g = newGlobal({newCompartment: true});
+g.eval(`\
+    function f1() {}        // line 1
+    function f2() {}        //  2
+    function f3() {}        //  3
+                            //  4
+    function* gen(          //  5
+        name,               //  6
+        schema = f1(),      //  7
+        timeToLive = f2(),  //  8
+        lucidity = f3()     //  9
+    ) {                     // 10
+    }                       // 11
+`);
+
+let dbg = Debugger(g);
+let log = [];
+dbg.onEnterFrame = frame => {
+    frame.onStep = () => {
+        let line = frame.script.getOffsetLocation(frame.offset).lineNumber;
+        if (log.length == 0 || line != log[log.length - 1]) {
+            log.push(line);
+        }
+    };
+};
+
+g.gen(0);
+assertDeepEq(log, [5, 7, 1, 8, 2, 9, 3, 10]);