JavaScript error in "AdGuard Extra.user.js" in older browsers versions

[ameshkov]

@victor-homyakov commented on Wed Jun 19 2019

Steps to reproduce

1. Install older version of Chrome (53 and older) or Opera (40 and older)
2. Install AdGuard with AdGuard Extra script
3. Open yandex.ru

Expected behavior

No errors should happen

Actual behavior

Older browsers (Opera 40 and older, Chrome 53 and older) will throw JavaScript error

TypeError: Object.values is not a function
    at findAds (AdGuard%20Extra.user.js:71:7335)
    at hideYaDirectAds (AdGuard%20Extra.user.js:71:7938)
    at MutationObserver.eval (AdGuard%20Extra.user.js:71:8766)

because JavaScript in AdGuard Extra.user.js uses Object.values(), which isn't supported in older browser versions https://caniuse.com/#search=Object.values.

Your environment

• AdGuard AdBlocker extension version:
• Environment name and version: Chrome/53.0.2785.21
• Filters you use in AdGuard:
• Any other browser extensions you have installed: none

[victor-homyakov]

Also script https://userscripts.adtidy.org/beta/adguard-extra/1.0/adguard-extra.user.js contains the same function repeated five times with different names:

    function d(e) {
        return function(e) {
            if (Array.isArray(e)) {
                for (var t = 0, n = new Array(e.length); t < e.length; t++) n[t] = e[t];
                return n
            }
        }(e) || function(e) {
            if (Symbol.iterator in Object(e) || "[object Arguments]" === Object.prototype.toString.call(e)) return Array.from(e)
        }(e) || function() {
            throw new TypeError("Invalid attempt to spread non-iterable instance")
        }()
    }

...

    function g(e) {
        return function(e) {
            if (Array.isArray(e)) {
                for (var t = 0, n = new Array(e.length); t < e.length; t++) n[t] = e[t];
                return n
            }
        }(e) || function(e) {
            if (Symbol.iterator in Object(e) || "[object Arguments]" === Object.prototype.toString.call(e)) return Array.from(e)
        }(e) || function() {
            throw new TypeError("Invalid attempt to spread non-iterable instance")
        }()
    }

...

    function m(e) {
        return function(e) {
            if (Array.isArray(e)) {
                for (var t = 0, n = new Array(e.length); t < e.length; t++) n[t] = e[t];
                return n
            }
        }(e) || function(e) {
            if (Symbol.iterator in Object(e) || "[object Arguments]" === Object.prototype.toString.call(e)) return Array.from(e)
        }(e) || function() {
            throw new TypeError("Invalid attempt to spread non-iterable instance")
        }()
    }

...

    function w(e) {
        return function(e) {
            if (Array.isArray(e)) {
                for (var t = 0, n = new Array(e.length); t < e.length; t++) n[t] = e[t];
                return n
            }
        }(e) || function(e) {
            if (Symbol.iterator in Object(e) || "[object Arguments]" === Object.prototype.toString.call(e)) return Array.from(e)
        }(e) || function() {
            throw new TypeError("Invalid attempt to spread non-iterable instance")
        }()
    }

    function S(e) {
        return function(e) {
            if (Array.isArray(e)) {
                for (var t = 0, n = new Array(e.length); t < e.length; t++) n[t] = e[t];
                return n
            }
        }(e) || function(e) {
            if (Symbol.iterator in Object(e) || "[object Arguments]" === Object.prototype.toString.call(e)) return Array.from(e)
        }(e) || function() {
            throw new TypeError("Invalid attempt to spread non-iterable instance")
        }()
    }

Looks like a new function is inserted for each transpiled spread operator. In any case there is an opportunity for improvement.

[ameshkov]

Yeah, we don't use plugin-transform-runtime as it tends to pollute global scope even when corejs 3 is enabled. Anyways, we can improve the build process to avoid duplications, thanks for reporting it!