src/third_party/mozjs-45/js/src/jit-test/tests/debug/Object-displayName-01.js

// Debugger.Object.prototype.displayName

var g = newGlobal();
var dbg = Debugger(g);
var name;
dbg.onDebuggerStatement = function (frame) { name = frame.callee.displayName; };

g.eval("(function f() { debugger; })();");
assertEq(name, "f");
g.eval("(function () { debugger; })();");
assertEq(name, undefined);
g.eval("Function('debugger;')();");
assertEq(name, "anonymous");
g.eval("var f = function() { debugger; }; f()");
assertEq(name, "f");
g.eval("var a = {}; a.f = function() { debugger; }; a.f()");
assertEq(name, "a.f");