Handle Reference Error by making variable `undefined`

[the-e3n]

Hi, I would like to make it such that any unbound or not available variable value is interpreted as undefined instead of causing Reference Error. Is there any way to handle this? I know we can handle this in the code by using typeof variableName !=='undefined' to avoid reference error but i am using it as sort of transform layer and don't know which variables will be not passed in the context. any way to fix this?