string.prototype.startswith polyfill does not work in IE 11

[Ajji11]

Bug Report

Ionic Info

Describe the Bug
A clear and concise description of what the bug is.

Although a polyfill exists on the project a .startswith function is throwing a 'Syntax' error in IE 11, preventing the website from loading.

Polyfill for string.prototype.startswith is in the project and works for every other string.startswith.

Steps to Reproduce
Include AWS-Amplify / AWS-Amplify-Angular in Angular project and use one of the modules. It adds ionic/core dependency which has this function causing the issue. In my case I used AmplifyService.api().

Related Code

function configFromURL() {
    const config = {};
    const win = window;
    win.location.search.slice(1)
        .split('&')
        .filter(entryText => entryText.startsWith('ionic:'))
        .map(entryText => entryText.split('='))
        .forEach(entry => {
        config[entry[0].slice(6)] = decodeURIComponent(entry[1]);
    });
    return config;
}

This line is causing the break: .filter(entryText => entryText.startsWith('ionic:'))

Expected Behavior
Polyfill should work and website should load in IE11

Additional Context
List any other information that is relevant to your issue. Stack traces, related issues, suggestions on how to fix, Stack Overflow links, forum links, screenshots, OS if applicable, etc.

[dertuerke]

Nope its not closed. Same error with Beta1

[Ajji11]

@manucorporat - yes, I'm facing the same error. It's still trying to use string.startswith instead of the new function.

[ionitron-bot]

Thanks for the issue! This issue is being locked to prevent comments that are not relevant to the original issue. If this is still an issue with the latest version of Ionic, please create a new issue and ensure the template is fully filled out.