[BUGFIX] DocumentFragment support - pairity with Element placed via {{ }} and via {{#in-element}}

[NullVoxPopuli]

Continuation of:

• [BUGFIX] {{#in-element}} with DocumentFragment targets, continued #21550

Which is a continuation of:

• [BUGFIX] DocumentFragment support — {{#in-element}} with DocumentFragment targets #21253

This is required to unblock using shadow-dom with out whack hacks.

See:

• [Quest]: Proper ShadowDOM support #20644

Demo of this PR working (REPL)

test code for the repl

import Component from '@glimmer/component';
import { trackedObject } from '@ember/reactive/collections';

const state = trackedObject({
  count: 0,
  inc: () => state.count++,
});


const fragment = document.createDocumentFragment();

setInterval(() => {
    console.log(fragment.textContent)
}, 250);

<template>
  check the console 

  <hr>
  as a separate PR we need to make fragments renderable
  today, folks would need a modifier to append the fragment to the DOM, 
  which could cause Glimmer to get confused by someone else managing DOM:
  {{fragment}}

  {{#in-element fragment}}
    text in a fragment
    {{log "in-element body"}}
    {{state.count}}

    <button onclick={{state.inc}}>inc</button>
  {{/in-element}}

  <hr> 
  
  outside the fragement is useful for testing reactivity
  <button onclick={{state.inc}}>inc</button>
</template> 

REPL deploy info

CI run: https://github.com/NullVoxPopuli/limber/actions/runs/31221384086
Preview PR: NullVoxPopuli/limber#2211
REPL with this change: https://test-ember-source-nvp-in-ele.limber-glimdown.pages.dev/

Perf is good.

---

Out of scope

• insertBefore values other than null/undefined (unchanged from Element destinations).

[github-actions]

📊 Size report

Tarball size — 1.2 MB → 1.2 MB

dist/dev   0.5%↑

File	Before (Size / Brotli)	After (Size / Brotli)
./packages/shared-chunks/api-{hash}.js	26.3 kB / 5.9 kB	18%↑31 kB / 22%↑7.2 kB
./packages/shared-chunks/normalize-{hash}.js	2.2 kB / 617 B	30%↑2.9 kB / 38%↑849 B
./packages/shared-chunks/rehydrate-{hash}.js	15.6 kB / 3.1 kB	23%↑19.1 kB / 24%↑3.9 kB
./packages/shared-chunks/render-{hash}.js	56.1 kB / 12.2 kB	0.4%↑56.3 kB / 0.8%↑12.3 kB
./packages/shared-chunks/serialize-{hash}.js	3.6 kB / 1 kB	19%↑4.3 kB / 17%↑1.2 kB
./packages/shared-chunks/template-{hash}.js	491 B / 203 B	118%↑1.1 kB / 98%↑401 B
Total (Includes all files)	2.1 MB / 492.5 kB	0.5%↑2.1 MB / 0.5%↑495.1 kB

---

dist/prod   0.5%↑

File	Before (Size / Brotli)	After (Size / Brotli)
./packages/shared-chunks/api-{hash}.js	5.9 kB / 1.5 kB	413%↑30.5 kB / 384%↑7.1 kB
./packages/shared-chunks/normalize-{hash}.js	2.2 kB / 617 B	30%↑2.9 kB / 38%↑849 B
./packages/shared-chunks/rehydrate-{hash}.js	15.6 kB / 3.1 kB	23%↑19.1 kB / 24%↑3.9 kB
./packages/shared-chunks/render-{hash}.js	52.4 kB / 11.3 kB	0.4%↑52.6 kB / 0.7%↑11.4 kB
./packages/shared-chunks/serialize-{hash}.js	3.6 kB / 1 kB	19%↑4.3 kB / 16%↑1.2 kB
Total (Includes all files)	1.9 MB / 450 kB	0.5%↑1.9 MB / 0.6%↑452.6 kB

---

smoke-tests/v2-app-template/dist   0.8%↑

File	Before (Size / Brotli)	After (Size / Brotli)
./assets/api-{hash}.js	290.5 kB / 78.1 kB	0.9%↑293.1 kB / 0.7%↑78.6 kB
Total (Includes all files)	342.8 kB / 95.1 kB	0.8%↑345.4 kB / 0.6%↑95.7 kB

---

smoke-tests/v2-app-hello-world-template/dist   0.7%↑

File	Before (Size / Brotli)	After (Size / Brotli)
./assets/main-{hash}.js	132.4 kB / 37 kB	0.7%↑133.4 kB / 0.8%↑37.3 kB
Total (Includes all files)	132.7 kB / 37.1 kB	0.7%↑133.7 kB / 0.9%↑37.5 kB

_{🤖 This report was automatically generated by wyvox/pkg-size}

[NullVoxPopuli]

someone's editor doesn't strip unneeded invisible characters :P

[NullVoxPopuli]

meaningful change here

[NullVoxPopuli]

"a"

[NullVoxPopuli]

Putting this back in draft while I re-learn what's going on (original work from March)

[NullVoxPopuli]

Deploy preview: https://test-ember-source-nvp-in-ele.limber-glimdown.pages.dev/