Why jQuery-migrate in not replacing depreciated functions directly in the code?

Question

Im using jQuery-migrate on a big project. I corrected all the warnings I could but now the warnings are inside libraries.

Some libraries are not updated anymore so I can't update them to make them work with jQuery-3.3.1. Also, I can't replace the depreciated functions directly in the libraires because it is creating errors.

So I think that I'll keep jQuery-migrate in my project.

My question is : If jQuery-migrate is able to correct the depreciated functions when called, why it can not correct them directly in the code ?

Answer 1

JavaScript does not lend itself to static code analysis.

Say you needed to replace the foo function.

That would be fairly trivial if the code that called it was simply:

something.foo();

It becomes rather harder if it is:

function call(bar, method) {
    bar[method]();
}

call(something, "foo");

… and even harder if the logic needed to get there was more complicated.

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Creating something.foo so it just exists if anything try to access it at runtime is much simpler.