BUG-028
ID:BUG-028Status:confirmed

figure silently drops every child that is not an image

figure's transform builds its children from imgs — the nodes passing isMediaNode — plus an optional figcaption (packages/runes/src/tags/figure.ts:82-87):

Severity:majorMilestone:v0.39.0Source:SPEC-106
changeset-release/main View source
Branches 6
History 5
  1. 1360c76
    Content editedby Claude
    docs(plan): close BUG-028 with resolution and PR
  2. edc0608
    Content editedby Claude
    test(runes): record figure's pre-fix output for BUG-028
  3. c9b8c9c
    Created (confirmed)by github-actions[bot]
  4. 1046f41
    Content editedby Claude
    docs(plan): add v0.39.0 milestone, Declarations part two
  5. 05da68c
    Content editedby Claude
    docs(plan): add SPEC-141 and the two bugs behind it

Steps to Reproduce

{% figure caption="My file" %}
{% snippet path="a.ts" /%}
{% /figure %}

Expected

Either the fence appears inside the figure, or the rune says it cannot hold one.

Actual

{ "name": "figure",
  "attributes": { "data-rune": "figure", "typeof": "ImageObject" },
  "children": [
    { "name": "figcaption", "attributes": { "data-name": "caption" },
      "children": ["My file"] } ] }

The <pre> is gone. No error, no warning, no build diagnostic. The page renders a caption floating under nothing.

Notes

  • Reproduced with a {% snippet %} because that is the case that surfaced it, but the cause has nothing to do with snippet — any non-media child is dropped the same way. A fenced code block written directly in the body behaves identically.
  • typeof="ImageObject" is emitted unconditionally, so a figure holding anything other than an image also publishes a wrong schema.org type. That part is SPEC-130's channel, but the trigger is the same assumption.
  • This blocks the composition SPEC-062 recommends. Its CSS comment tells authors wanting labelled chrome to reach for {% codegroup title="…" %} precisely because figure cannot serve — but nothing says so at the point of use, and the content model implies it can.
  • Severity is major rather than minor because the failure mode is silent content loss. A rune that refused the child would be a smaller problem.
  • Two defensible fixes, and they are not equivalent:
    1. Emit the non-media children in body order, keeping imgs as the media slot. Makes {% figure %} a general captioned-container and unblocks figure-wrapped snippets, tables and diagrams.
    2. Warn and drop, keeping figure image-only. Preserves the current contract and the ImageObject type, and makes the limit visible. The choice is a product decision about what figure is, so it belongs in a spec rather than being settled in the fix.

Decision

Fix 1: figure is a general captioned container. Decided when scheduling v0.39.0. Non-media children are emitted in body order, and imgs stays the media slot. Together with WORK-615, which removes snippet's own figure wrapper, this makes {% figure %} the documented way to give a snippet, table or diagram a caption.

What the fix still has to settle, and record in its resolution:

  • The schema.org type. typeof="ImageObject" cannot stay unconditional once a figure may hold a code fence. One option: keep ImageObject when the media slot is the figure's only content, and emit no type otherwise. That choice belongs in the schema table (SPEC-130), and the baseline diff is reviewed, not regenerated silently.
  • Contracts and CSS. The structure contract moves. Lumina's figure styles need to hold up for non-media bodies.
  • Docs. The figure rune page states what it accepts, and SPEC-062's "reach for codegroup instead" advice is revisited.

References

  • SPEC-106 — image src scheme sugar; where isMediaNode's admitted set comes from
  • SPEC-062 — the snippet rune, whose standalone chrome this interacts with
  • SPEC-141 — removes snippet's own figure wrapper, which makes this the recommended path