[Filters] Fix hitting max call depth when appliedFilters is undefined

[maael]

WHY are these changes introduced?

Currently appliedFilters can be undefined, except when it is when we try to setLocalPinnedFilters, we'll do so forever because we fail the check to decide whether to try set state or not every time, as !allAppliedFilterKeysInLocalPinnedFilters will always be true.

To avoid this, we should only try to make the local pinned filters match if we actually have any applied filters - and it's not undefined.

Found this while trying to bump to v11.20.0 from v11.19.0.

This was introduced in:

• [Filters] Fix bug where changes to appliedFilters prop don't get respected #10566

WHAT is this pull request doing?

Checking appliedFilters is defined before trying to setLocalPinnedFilters.

How to 🎩

🖥 Local development instructions
🗒 General tophatting guidelines
📄 Changelog guidelines

Example test that shows a bunch of re-renders

import React from 'react';
import {render} from '@testing-library/react';
import {Filters, PolarisTestProvider} from '@shopify/polaris';

function Test() {
  return (
    <PolarisTestProvider>
      <Filters filters={[]} />
    </PolarisTestProvider>
  );
}

describe('Testing', () => {
  it('does thing', () => {
    render(<Test />);
  });
});

Copy-paste this code in playground/Playground.tsx:

import React from 'react';
import {Page} from '../src';

export function Playground() {
  return (
    <Page title="Playground">
      {/* Add the code you want to test in here */}
    </Page>
  );
}

🎩 checklist

• Tested on mobile
• Tested on multiple browsers
• Tested for accessibility
• Updated the component's README.md with documentation changes
• Tophatted documentation changes in the style guide

[maael]

@mrcthms 👋 hey there - thanks for the review. First time contributing to Polaris, do I just squash and merge? How does this end up eventually in the package, is that all automatic? Anything for me to be aware of?

[mrcthms]

@maael Yeah, you can squash and merge, and Polaris will automatically merge this into the next release branch. You should see a PR in the Polaris PR list called "Version Packages" and once the merge has completed, you'll see your change in that branch. To release a new version of polaris-react you would merge that PR (once you've checked with any other authors of PRs also contained within the release), and then bump to web.

It's worth noting that I'm going to be refactoring the Filters component quite a bit, and removing everything within the useEffect where your changes have been made. But that won't be ready for around a day or two, so this should still def go out if we're seeing issues with the current implementation!

[maael]

Sounds good, thanks for the info!

I'll merge this then, and I'll leave it for another person to ship the Version Packages PR that this ends up in.