Webpack issue when compiling JS files

问题

I am working on a Laravel 5.3 project, I have been using webpack with no issues until I tried to add some configurations for ES6. These included addind babel packages to my npm module. It broke my code so I reverted back all the changes but now whenever I change a JS file and compile, this line is added to the final JS file and it causes the Vue instance to be undefined (The line appears whenever I run gulp whether I change a file or not). I am using this package laravel-elixir-vue-2 and from what I have gathered(though I might be wrong) I do need any more configurations to run it successfully as I have been using it that way for a few months.

/***/ function(module, exports) { 124 125 eval("var g;\r\n\r\n// This works in non-strict mode\r\ng = (function() { return this; })();\r\n\r\ntry {\r\n\t// This works if eval is allowed (see CSP)\r\n\tg = g || Function(\"return this\")() || (1,eval)(\"this\");\r\n} catch(e) {\r\n\t// This works if the window reference is available\r\n\tif(typeof window === \"object\")\r\n\t\tg = window;\r\n}\r\n\r\n// g can still be undefined, but nothing to do about it...\r\n// We return undefined, instead of nothing here, so it's\r\n// easier to handle this case. if(!global) { ...}\r\n\r\nmodule.exports = g;\r\n//# sourceMappingURL=data:application/json;charset=utf-8;base64,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"); 126 126

I have even cloned a previous version of my repo that was working but the issue persists. At first I thought that some PHPStorm settings I had done caused it but then I changed the editor to use Atom but the issue did not go away.

UPDATE I followed this link to install babel so that I can use ES6 format inside my .vue files but it broke my webpack instead. I have not used use strict anywhere in my code. I installed a clean git repo in another pc and it raised the issue too. Also it works where I have used vue outside .vue components

This is my gulpfile.js

const elixir = require('laravel-elixir');

require('laravel-elixir-vue-2');


elixir(function(mix) {
    mix.sass('app.scss')
       .webpack('app.js');
});

Comment below if any further clarification is needed.