__webpack_public_path__ in vuejs
The no-def ESLint rule is warning you about using an undeclared variable. You need to tell ESLint that __webpack_public_path__ is a global variable.
You can do it using either a comment in the JS file where you are using it (publicpath.js), e.g.:
/* global __webpack_public_path__:writable */
Or in your ESLint config:
{
"globals": {
"__webpack_public_path__": "writable"
}
}