1 files changed, 35 insertions, 0 deletions
diff --git a/js/src/jit-test/tests/debug/Frame-onStep-17.js b/js/src/jit-test/tests/debug/Frame-onStep-17.js
new file mode 100644
index 0000000000..a73bd2187c
--- /dev/null
+++ b/js/src/jit-test/tests/debug/Frame-onStep-17.js
@@ -0,0 +1,35 @@
+// Test how stepping interacts with for-in/of statements.
+
+var g = newGlobal({newCompartment: true});
+var dbg = new Debugger;
+var gw = dbg.addDebuggee(g);
+var log;
+var previous;
+
+dbg.onDebuggerStatement = function (frame) {
+  let debugLine = frame.script.getOffsetLocation(frame.offset).lineNumber;
+  log = '';
+  previous = '';
+  frame.onStep = function() {
+    let foundLine = this.script.getOffsetLocation(this.offset).lineNumber;
+    if (this.script.getLineOffsets(foundLine).indexOf(this.offset) >= 0) {
+      let thisline = (foundLine - debugLine).toString(16);
+      if (thisline !== previous) {
+        log += thisline;
+        previous = thisline;
+      }
+    }
+  };
+};
+
+function testOne(decl, loopKind) {
+  let body = "var array = [2, 4, 6];\ndebugger;\nfor (" + decl + " iter " +
+      loopKind + " array) {\n  print(iter);\n}\n";
+  g.eval(body);
+  assertEq(log, "12121214");
+}
+
+for (let decl of ["", "var", "let"]) {
+  testOne(decl, "in");
+  testOne(decl, "of");
+}