CreateReducer.js uses "startsWith" which is unsupported in IE11

[soavie]

Are you submitting a bug report or a feature request?

bug report

What is the current behavior?

Unable to input text into Redux Form Field in IE11. Results in "TypeError: Object doesn't support property or method 'startsWith'"

What is the expected behavior?

It should be possible to input text without throwing any errors in IE11.

What's your environment?

redux-form 7.4.2
IE11

Other information

Line causing the error:
https://github.com/erikras/redux-form/blob/v7.4.2/src/createReducer.js#L47

  if (path.startsWith('values')) {

Commit that introduced the error:
a97606f

String.prototype.startsWith() browser support:
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/startsWith

We've been able to work around this by using core-js to polyfill the feature.

[gustavohenke]

Thanks for the heads up. That seems to have been introduced in v7.4.0, and should be an easy fix, if you would like to go for it 🙂

[chrisjlee]

Any preference how this is done?

I was thinking on using this polyfill from MDN. is this polyfill sufficient?

if (!String.prototype.startsWith) {
	String.prototype.startsWith = function(search, pos) {
		return this.substr(!pos || pos < 0 ? 0 : +pos, search.length) === search;
	};
}

[gustavohenke]

Adding polyfills to Redux Form wouldn't be a good idea, but if you mean using its implementation, then yeah, that's an option.

An even better one would be to use a regular expression, like /^values/.test(path), as then others don't need to guess where the magic number of the .substr() call is coming from.

[chrisjlee]

Yes implementation-wise. Thank you @gustavohenke !

[gustavohenke]

PR #4128 with the fix has been merged. Watch out for new releases!

[ldthorne]

Hey @gustavohenke @erikras , do you know when there will be a new release with this included? I'd like to use this fix as I'm hitting the same issue, but haven't been able to because there's no release for it yet. Thanks!

[rebebop]

@erikras @gustavohenke any update on this?

[DonWasyl]

npm package isn't updated from 3 months, this fix was merged 2 months ago
@gustavohenke, @erikras is possible to update package in npm?

[gustavohenke]

I don't control the release cycle.

[abumalick]

@erikras We need a release to fix this bug please

[leocristofani]

This issue is marked as closed, but it persists because #4128 has been merged into master, but not released yet. Any idea when this is going to be released? Thanks very much!

[davidgtu]

@soavie I'm having this issue as well. how did you get around this using core-js?

[abumalick]

import 'core-js/modules/es6.string.starts-with'; // redux-form
in the beginning of your app

[shorif2000]

I am having this issue in 7.4.2. i have tried to add import 'core-js/modules/es6.string.starts-with'; but it has not helped. my form also contains ['object Object'] and this occurs when i try to browse to another component/path. it is not browser dependant.

[erikras]

Published fix in v8.0.0.

[lock]

This thread has been automatically locked since there has not been any recent activity after it was closed. Please open a new issue for related bugs.