src/third_party/mozjs-45/js/src/jit-test/tests/debug/Object-script-lazy.js

// Asking for the script of a Debugger.Object should work, even when lazy
// functions are involved.

// Note that we never hand out the scripts of non-debuggee functions, and
// putting a compartment in debug mode automatically de-lazifies all its
// functions. (This ensures that findScripts works, too.)
//
// So here we create a reference to a non-debuggee function, verify that we
// can't access its interesting properties, make it a debuggee, and verify
// that everything becomes available.

// Create functions f, g in a non-debuggee compartment.
var g1 = newGlobal();
g1.eval('function f() { return "from f"; }');
g1.eval('function g() { return "from g"; }');

// Create a debuggee compartment with CCWs referring to f and g.
var g2 = newGlobal();
var dbg = new Debugger;
var g2w = dbg.addDebuggee(g2);
g2.f = g1.f;
g2.g = g1.g;

// At this point, g1.f should still be a lazy function. Unwrapping a D.O
// referring to g2's CCW of f should yield a D.O referring to f directly.
// Asking for that second D.O's script should yield null, because it's not
// a debuggee.
var fDO = g2w.getOwnPropertyDescriptor('f').value;
assertEq(fDO.global, g2w);
assertEq(fDO.unwrap().global === g2w, false);
assertEq(fDO.unwrap().script, null);

// Similarly for g1.g, and asking for its parameter names.
var gDO = g2w.getOwnPropertyDescriptor('g').value;
assertEq(gDO.global, g2w);
assertEq(gDO.unwrap().global === g2w, false);
assertEq(gDO.unwrap().parameterNames, undefined);

// Add g1 as a debuggee, and verify that we can get everything.
dbg.addDebuggee(g1);
assertEq(fDO.unwrap().script instanceof Debugger.Script, true);
assertEq(gDO.unwrap().parameterNames instanceof Array, true);