feat(disclosure): add <rh-disclosure>

[adamjohnson]

What I did

1. Created the <rh-disclosure> element
2. Added a few tests

Testing Instructions

1. Visit the <rh-disclosure> demo on the DP.
2. Also visit the Nested Disclosures demo.

To do's

• Docs
• Fix git main 👉 staging/cubone + diff
• Fix border / border colors in DP

Notes to Reviewers

This element is lightdom based. We're planning to use it standalone as <rh-disclosure> and also using it in <rh-navigation-XYZ> for dropdowns.

Shout out to @zeroedin for the initial concept.

Closes #1293.

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Latest commit: 5c8d706

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[github-actions]

Size Change: +1.02 kB (+0.48%)

Total Size: 212 kB

Filename	Size	Change
./elements.js	480 B	+7 B (+1.48%)
./lib/environment.js	4.1 kB	+6 B (+0.15%)
./elements/rh-disclosure/rh-disclosure.js	828 B	+828 B (new file)	🆕
./react/rh-disclosure/rh-disclosure.js	179 B	+179 B (new file)	🆕

ℹ️ View Unchanged

Filename	Size
./elements/rh-accordion/context.js	162 B
./elements/rh-accordion/rh-accordion-header.js	2.77 kB
./elements/rh-accordion/rh-accordion-panel.js	1.37 kB
./elements/rh-accordion/rh-accordion.js	3.21 kB
./elements/rh-alert/rh-alert.js	4.31 kB
./elements/rh-audio-player/rh-audio-player-about.js	1.85 kB
./elements/rh-audio-player/rh-audio-player-rate-stepper.js	1.85 kB
./elements/rh-audio-player/rh-audio-player-scrolling-text-overflow.js	1.53 kB
./elements/rh-audio-player/rh-audio-player-subscribe.js	1.43 kB
./elements/rh-audio-player/rh-audio-player.js	13.2 kB
./elements/rh-audio-player/rh-cue.js	2 kB
./elements/rh-audio-player/rh-transcript.js	2.75 kB
./elements/rh-avatar/random-pattern-controller.js	2.72 kB
./elements/rh-avatar/rh-avatar.js	2.9 kB
./elements/rh-back-to-top/rh-back-to-top.js	2.1 kB
./elements/rh-badge/rh-badge.js	1.55 kB
./elements/rh-blockquote/rh-blockquote.js	1.41 kB
./elements/rh-breadcrumb/rh-breadcrumb.js	1.5 kB
./elements/rh-button/rh-button.js	4.24 kB
./elements/rh-card/rh-card.js	3.64 kB
./elements/rh-code-block/prism.css.js	822 B
./elements/rh-code-block/prism.js	572 B
./elements/rh-code-block/rh-code-block.js	7.25 kB
./elements/rh-cta/rh-cta.js	3.96 kB
./elements/rh-dialog/rh-dialog.js	4.78 kB
./elements/rh-dialog/yt-api.js	617 B
./elements/rh-footer/rh-footer-block.js	766 B
./elements/rh-footer/rh-footer-copyright.js	362 B
./elements/rh-footer/rh-footer-links.js	1.17 kB
./elements/rh-footer/rh-footer-social-link.js	964 B
./elements/rh-footer/rh-footer-universal.js	4.05 kB
./elements/rh-footer/rh-footer.js	5.01 kB
./elements/rh-health-index/rh-health-index.js	2.35 kB
./elements/rh-icon/rh-icon.js	2.35 kB
./elements/rh-icon/ssr.js	181 B
./elements/rh-menu/rh-menu.js	1.29 kB
./elements/rh-navigation-secondary/rh-navigation-secondary-dropdown.js	2.47 kB
./elements/rh-navigation-secondary/rh-navigation-secondary-menu-section.js	1.35 kB
./elements/rh-navigation-secondary/rh-navigation-secondary-menu.js	1.75 kB
./elements/rh-navigation-secondary/rh-navigation-secondary-overlay.js	571 B
./elements/rh-navigation-secondary/rh-navigation-secondary.js	5.31 kB
./elements/rh-navigation-secondary/test/fixtures.js	769 B
./elements/rh-pagination/rh-pagination.js	5.46 kB
./elements/rh-site-status/rh-site-status.js	2.5 kB
./elements/rh-skip-link/rh-skip-link.js	1.24 kB
./elements/rh-spinner/rh-spinner.js	1.43 kB
./elements/rh-stat/rh-stat.js	2.2 kB
./elements/rh-subnav/rh-subnav.js	2.73 kB
./elements/rh-surface/rh-surface.js	1.11 kB
./elements/rh-surface/test/elements.js	423 B
./elements/rh-switch/rh-switch.js	2.93 kB
./elements/rh-table/rh-sort-button.js	1.49 kB
./elements/rh-table/rh-table.js	3.54 kB
./elements/rh-tabs/context.js	160 B
./elements/rh-tabs/rh-tab-panel.js	1.04 kB
./elements/rh-tabs/rh-tab.js	3.02 kB
./elements/rh-tabs/rh-tabs.js	3.77 kB
./elements/rh-tag/rh-tag.js	2.84 kB
./elements/rh-tile/rh-tile-group.js	1.81 kB
./elements/rh-tile/rh-tile.js	5.15 kB
./elements/rh-timestamp/rh-timestamp.js	983 B
./elements/rh-tooltip/rh-tooltip.js	2.24 kB
./elements/rh-video-embed/rh-video-embed.js	4.6 kB
./lib/context/color/consumer.js	1.35 kB
./lib/context/color/controller.js	947 B
./lib/context/color/provider.js	2.18 kB
./lib/context/event.js	593 B
./lib/context/headings/consumer.js	722 B
./lib/context/headings/controller.js	1.12 kB
./lib/context/headings/provider.js	1.24 kB
./lib/DirController.js	565 B
./lib/elements/rh-context-demo/rh-context-demo.js	1.28 kB
./lib/elements/rh-context-picker/rh-context-picker.js	2.24 kB
./lib/functions.js	175 B
./lib/I18nController.js	1.38 kB
./lib/ScreenSizeController.js	849 B
./lib/ssr-controller.js	251 B
./react/rh-accordion/rh-accordion-header.js	199 B
./react/rh-accordion/rh-accordion-panel.js	185 B
./react/rh-accordion/rh-accordion.js	215 B
./react/rh-alert/rh-alert.js	184 B
./react/rh-audio-player/rh-audio-player-about.js	191 B
./react/rh-audio-player/rh-audio-player-rate-stepper.js	213 B
./react/rh-audio-player/rh-audio-player-scrolling-text-overflow.js	214 B
./react/rh-audio-player/rh-audio-player-subscribe.js	196 B
./react/rh-audio-player/rh-audio-player.js	183 B
./react/rh-audio-player/rh-cue.js	195 B
./react/rh-audio-player/rh-transcript.js	207 B
./react/rh-avatar/rh-avatar.js	173 B
./react/rh-back-to-top/rh-back-to-top.js	183 B
./react/rh-badge/rh-badge.js	174 B
./react/rh-blockquote/rh-blockquote.js	179 B
./react/rh-breadcrumb/rh-breadcrumb.js	179 B
./react/rh-button/rh-button.js	174 B
./react/rh-card/rh-card.js	172 B
./react/rh-code-block/rh-code-block.js	181 B
./react/rh-cta/rh-cta.js	170 B
./react/rh-dialog/rh-dialog.js	203 B
./react/rh-footer/rh-footer-block.js	184 B
./react/rh-footer/rh-footer-copyright.js	187 B
./react/rh-footer/rh-footer-links.js	185 B
./react/rh-footer/rh-footer-social-link.js	193 B
./react/rh-footer/rh-footer-universal.js	188 B
./react/rh-footer/rh-footer.js	174 B
./react/rh-health-index/rh-health-index.js	184 B
./react/rh-icon/rh-icon.js	202 B
./react/rh-menu/rh-menu.js	173 B
./react/rh-navigation-secondary/rh-navigation-secondary-dropdown.js	217 B
./react/rh-navigation-secondary/rh-navigation-secondary-menu-section.js	205 B
./react/rh-navigation-secondary/rh-navigation-secondary-menu.js	199 B
./react/rh-navigation-secondary/rh-navigation-secondary-overlay.js	201 B
./react/rh-navigation-secondary/rh-navigation-secondary.js	213 B
./react/rh-pagination/rh-pagination.js	178 B
./react/rh-site-status/rh-site-status.js	181 B
./react/rh-skip-link/rh-skip-link.js	181 B
./react/rh-spinner/rh-spinner.js	175 B
./react/rh-stat/rh-stat.js	171 B
./react/rh-subnav/rh-subnav.js	175 B
./react/rh-surface/rh-surface.js	175 B
./react/rh-switch/rh-switch.js	185 B
./react/rh-table/rh-sort-button.js	213 B
./react/rh-table/rh-table.js	174 B
./react/rh-tabs/rh-tab-panel.js	181 B
./react/rh-tabs/rh-tab.js	187 B
./react/rh-tabs/rh-tabs.js	174 B
./react/rh-tag/rh-tag.js	182 B
./react/rh-tile/rh-tile-group.js	183 B
./react/rh-tile/rh-tile.js	194 B
./react/rh-timestamp/rh-timestamp.js	176 B
./react/rh-tooltip/rh-tooltip.js	175 B
./react/rh-video-embed/rh-video-embed.js	227 B
./uxdot/uxdot-best-practice.js	742 B
./uxdot/uxdot-copy-button.js	1.2 kB
./uxdot/uxdot-copy-permalink.js	1.1 kB
./uxdot/uxdot-example.js	1.17 kB
./uxdot/uxdot-feedback.js	727 B
./uxdot/uxdot-header.js	1.07 kB
./uxdot/uxdot-hero.js	679 B
./uxdot/uxdot-installation-tabs.js	675 B
./uxdot/uxdot-masthead.js	809 B
./uxdot/uxdot-pattern-ssr-controller-client.js	536 B
./uxdot/uxdot-pattern-ssr-controller-server.js	1.66 kB
./uxdot/uxdot-pattern-ssr-controller.js	213 B
./uxdot/uxdot-pattern.js	2.07 kB
./uxdot/uxdot-repo-status-checklist.js	1.16 kB
./uxdot/uxdot-repo-status-list.js	1.07 kB
./uxdot/uxdot-repo-status-table.js	782 B
./uxdot/uxdot-repo.js	1.17 kB
./uxdot/uxdot-search.js	2.39 kB
./uxdot/uxdot-sidenav.js	2.67 kB
./uxdot/uxdot-spacer-tokens-table.js	2.45 kB
./uxdot/uxdot-toc.js	1.13 kB

_{compressed-size-action}

[bennypowers]

I'm curious why you opted to make <rh-disclosure> a decorator. From a strictly custom-element perspective, and based on prior discussions we've had about it, "disclosure" and "details" should be interchangeable concepts, so having one explicitly depend on the user using the other is on some level confusing. It also limits us. We may at some point discover that we have compelling reasons to develop our own disclosure behaviour without the <details> element being involved at all. If we place it in the shadow DOM only, we'd be able to make such changes in a patch release.

Late-2000s haute cuisine trends aside, it would be a touch annoying to order a burger and have the patty, buns, veg, and sauce, all come in separate containers with assembly instructions stapled to the bag. As custom-element authors, we should have the confidence to define our own behaviours.

Tn other words, if <rh-disclosure> is merely a decorator element, why not just make this a pattern and recommend some global CSS rules? Can you elaborate on the decision to make user light-dom a requirement?

if downstream teams "need" lightdom details (which is in my view an antipattern) what about making it opt-in?

---

Elaborating on my position: we should make the maximum effort to avoid requiring lightdom which performs the same function. This is to gain maximum benefit from custom elements and shadow dom, namely encapsulation and interoperability. There have been and will likely continue to be instances where the state of the art gives us no choice, for example I suspect that pfe's radio and checkbox elements will have to manage their own lightdom, although I'm concerned that this might break under the control of "VDOMs" like react. In the future, when reference targets, aria IDL attributes, more ElementInternals apis, and improvements to formAssociated become widely available in browsers, we'll be able to "tighten our belts" so to speak and regain some of the control which we had to give up for the sake of correctness.

In the case of disclosure though, I haven't yet seen the show-stopping must-have requirement that the details element must be present and in light DOM.

---

So all that in mind, I challenge you to imagine a disclosure element in which <details> is a hot-swappable, private, internal implementation detail which the downstream user need not concern themselves with.