michael@0: var g = newGlobal();
michael@0: var dbg = new Debugger;
michael@0: var gw = dbg.addDebuggee(g);
michael@0: var log;
michael@0: var a = [];
michael@0: 
michael@0: dbg.onDebuggerStatement = function (frame) {
michael@0:   log += 'd';
michael@0:   frame.onStep = function () {
michael@0:     // This handler must not wipe out the debuggee's value in JSContext::iterValue.
michael@0:     log += 's';
michael@0:     // This will use JSContext::iterValue in the debugger.
michael@0:     for (let i of a)
michael@0:       log += 'i';
michael@0:   };
michael@0: };
michael@0: 
michael@0: log = '';
michael@0: g.eval("debugger; for (let i of [1,2,3]) print(i);");
michael@0: assertEq(!!log.match(/^ds*$/), true);