Maintenance: Move filtering of sidebar into the state

[ndelangen]

What I did

When implementing filtering I forgot about the effect this would have on keyboard navigation.

I had left the index in state untouched, which would cause navigating via keyboard shortcuts to be incorrect.

I've moved the logic for filtering into the state manager (manager-api).
The index kept in state is now filtered before reaching the sidebar.

The interface for FilterFunctions changed slightly.

Checklist for Contributors

Testing

The changes in this PR are covered in the following automated tests:

• stories
• unit tests
• integration tests
• end-to-end tests

Manual testing

Set the ui/.storybook/manager.tsx code to this:

import React from 'react';
import { addons, types } from '@storybook/manager-api';
import startCase from 'lodash/startCase.js';

addons.register('XYYYZZ', (api) => {
  addons.add('XYYYZZ/panel', {
    type: types.TOOL,
    title: 'TEST',
    match: ({ viewMode }) => true,

    render: () => (
      <div>
        <button type="button" onClick={() => api.experimental_setFilter('manager', () => true)}>
          TEST
        </button>
      </div>
    ),
  });
});
addons.setConfig({
  sidebar: {
    renderLabel: ({ name, type }) => (type === 'story' ? name : startCase(name)),
    filters: {
      manager: ({ title }) => title.includes('core'),
    },
  },
});

And start the UI storybook.

Expect the sidebar to be filtered when storybook opens.
Only stories that have the word core in them (anywhere in the path) should be visisble.

Use the keyboard shurtcuts to navigate between stories & components.

Now click the "TEST" button in the toolbar.

Expect the sidebar to now display all items (though collepsed)

Use the keyboard shurtcuts to navigate between stories & components.

Documentation

• Add or update documentation reflecting your changes
• If you are deprecating/removing a feature, make sure to update
  MIGRATION.MD

Checklist for Maintainers

• When this PR is ready for testing, make sure to add ci:normal, ci:merged or ci:daily GH label to it to run a specific set of sandboxes. The particular set of sandboxes can be found in code/lib/cli/src/sandbox-templates.ts

• Make sure this PR contains one of the labels below:

  Available labels

  • bug: Internal changes that fixes incorrect behavior.
  • maintenance: User-facing maintenance tasks.
  • dependencies: Upgrading (sometimes downgrading) dependencies.
  • build: Internal-facing build tooling & test updates. Will not show up in release changelog.
  • cleanup: Minor cleanup style change. Will not show up in release changelog.
  • documentation: Documentation only changes. Will not show up in release changelog.
  • feature request: Introducing a new feature.
  • BREAKING CHANGE: Changes that break compatibility in some way with current major version.
  • other: Changes that don't fit in the above categories.

🦋 Canary release

This PR does not have a canary release associated. You can request a canary release of this pull request by mentioning the @storybookjs/core team here.

core team members can create a canary release here or locally with gh workflow run --repo storybookjs/storybook canary-release-pr.yml --field pr=<PR_NUMBER>

[tmeasday]

Looks good! Can we add a couple of tests that check the filtering updates when you change filters or statuses or when a new index arrives?

[tmeasday]

👏