(function(){ var captured1 = { used1: 42, unused1: 42 // $ Alert }; captured1.used1; var unused2 = { unused2a: 42, unused2b: 42 }; for (x.p in { used3: 42 }); for (x.p of { used4: 42 }); 42 in { used5: 42 }; f(...{used6: 42}); [...{used7: 42}]; ({...{used8: 42}}); ({ unused9: 42 }) + ""; // $ Alert ({ used10: 42 }).hasOwnProperty; ({ used10: 42 }).propertyIsEnumerable; (function(){ var captured11 = { used11: 42, unused11: 42 // $ Alert }; captured11.used11; var captured12 = { used12_butNotReally: 42, // $ Alert unused12: 42 // $ Alert }; throw x; captured12.used12_butNotReally; var captured13 = { used13: 42, unused13: 42 }; captured13.used13; }); (function(options){ if(unknown) options = {}; options.output = 42; }); var captured14 = { unused14: 42 // $ Alert }; captured14.unused14 = 42; // $ Alert captured14.unused14 = 42; // $ Alert var captured15 = { semiUnused15: 42 }; captured15.semiUnused15 = 42; captured15.semiUnused15; }); (function(unusedParam = {unusedProp: 42}){ }); (function(){ var unusedObj = { unusedProp: 42 }; }); (function(){ var unusedSpecials = { toString: function(){}, valueOf: function(){}, '@@iterator': function(){} }; unusedSpecials.foo; }); (function(){ ({ unusedProp: 42 }, 42); }); (function(){ var foo = { unused: 42 }; foo.unused = 42; Object.hasOwn(foo, blab); });