fix(tiptap): preserve YAML array-of-objects component props in round-trip

[hendrikheil]

Problem

Editing a component with YAML block array-of-objects props in Studio corrupts them on save:

::authors
---
authorsOne:
  - name: John Doe
    role: contributor
---
::

becomes:

::authors{:authorsOne="[{"name":"John Doe","role":"contributor"}]"}
::

Closes #457. Supersedes #477.

Root cause (two bugs)

1. propsMDCToComark didn't unwrap @nuxtjs/mdc binding-syntax props

@nuxtjs/mdc serialises non-primitive YAML block props (arrays, objects) as Vue binding syntax — key :authorsOne (: prefix) with a JSON-stringified string value "[{\"name\":\"John\"}]". The propsMDCToComark bridge in legacy.ts passed these through unchanged, so the entire pipeline carried a JSON string instead of a real JavaScript array. When comark rendered the ComarkElement back to markdown, it emitted the inline binding form {:authorsOne="[...]"} — exactly the corruption seen in production.

2. normalizeProps was built on a "all props are strings" assumption

String(value).trim() on every prop value was wrong in principle. Comark attrs are already the correct type from the parser (string for inline attrs, number/boolean/array/object for YAML block attrs), and comark's renderer handles all these types natively. The stringification was a latent correctness bug even when it wasn't the immediate cause of corruption.

Fix

legacy.ts — propsMDCToComark (root cause fix): detect :key binding props produced by @nuxtjs/mdc and JSON.parse their values back to real JavaScript values, stripping the : prefix.

props.ts — normalizeProps (type correctness): rewritten to pass values through untouched, returning ComarkElementAttributes directly instead of Array<[string, unknown]>. Key trimming and empty-key filtering are preserved — they guard against user-typed custom props from the form editor which may have stray whitespace.

tiptapToComark.ts: both call sites updated — Object.fromEntries(propsArray) middleman removed since normalizeProps now returns the attrs object directly.

Test plan

• Unit tests for normalizeProps: values pass through as their original type (number stays number, array stays array, null stays null); key trimming and empty-key filtering work
• Unit tests for propsMDCToComark: :key bindings are unwrapped to real JS values; full round-trip through the legacy bridge renders YAML block format, not inline JSON
• Integration test: full comark → TipTap → comark → markdown round-trip with YAML array-of-objects props preserves structure and renders correct YAML block output
• All 347 tests pass

🤖 Generated with Claude Code

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[pkg-pr-new]

npm i https://pkg.pr.new/nuxt-studio@485

commit: fc9baea