EmDash Plugin Block Attr Patch

May 10, 2026 ยท View on GitHub

This repository carries a local patch against emdash@0.10.0 so Portable Text plugin blocks can persist arbitrary attributes through the editor roundtrip.

This is not an optional implementation detail. The patch is required for rich propertyEmbed blocks to retain fields like:

  • slug
  • variant
  • ctaLabel

Without the patch, EmDash collapses custom plugin blocks to a narrower stored shape and those additional fields are lost during edit/save cycles.

Why This Patch Exists

The original local behavior in EmDash's editor only safely persisted:

{
  "_type": "propertyEmbed",
  "_key": "abc123",
  "id": "beautiful-villa-marbella"
}

That forced the first propertyEmbed implementation in this repo to overload id with the property slug and avoid exposing richer embed settings.

The product requirement is broader. We need to support blocks like:

{
  "_type": "propertyEmbed",
  "_key": "abc123",
  "slug": "beautiful-villa-marbella",
  "variant": "compact",
  "ctaLabel": "View Property"
}

That requires the editor to preserve arbitrary plugin-block attrs rather than only a minimal id.

What The Patch Changes

The patch updates the EmDash editor implementation so:

  1. Portable Text plugin blocks are converted into ProseMirror attrs without discarding custom keys.
  2. ProseMirror pluginBlock nodes are converted back into Portable Text blocks with the original attrs restored.
  3. _type and _key are reconstructed correctly.
  4. Custom attrs like slug, variant, ctaLabel, booleans, and other primitive fields survive editor roundtrips.

The patch currently affects:

  • src/components/InlinePortableTextEditor.tsx
  • src/components/plugin-block-attrs.ts

Those paths are inside the patched emdash package, not this repo's own src/.

Reproducible Patch Workflow

This repository does not rely on hand-edited node_modules as the source of truth.

The patch is tracked using pnpm's patched dependency workflow:

package.json contains:

{
  "pnpm": {
    "patchedDependencies": {
      "emdash@0.10.0": "patches/emdash@0.10.0.patch"
    }
  }
}

That means a normal pnpm install will reapply the patch automatically.

How The Patch Was Created

The patch was generated with pnpm's native patch commands:

pnpm patch emdash@0.10.0 --edit-dir /tmp/emdash-patch
pnpm patch-commit /tmp/emdash-patch --patches-dir patches

This approach is preferable to force-adding files from node_modules because:

  • the patch is tracked in a single reviewable file
  • installs are reproducible
  • upgrading emdash later has a clear rebase point
  • CI and other developers can apply the same fix automatically

How To Update The Patch Later

If you need to change the EmDash editor behavior again:

  1. Run pnpm patch emdash@0.10.0 --edit-dir /tmp/emdash-patch
  2. Update the extracted package files in /tmp/emdash-patch
  3. Run tests in this repository before committing
  4. Run pnpm patch-commit /tmp/emdash-patch --patches-dir patches
  5. Review changes in:

Verification

The minimum verification for this patch is:

pnpm exec vitest run src/lib/pwb-property-embed-roundtrip.test.ts

That test suite covers:

  • helper roundtrip behavior for arbitrary plugin-block attrs
  • fallback key generation
  • plugin block registration for slug, variant, and ctaLabel
  • repository wiring for the pnpm patched dependency

For manual verification:

  1. run npx emdash dev
  2. open the admin editor
  3. insert a Property block
  4. set slug, variant, and ctaLabel
  5. save and reload the entry
  6. confirm all three fields survive the editor roundtrip

Known Constraints

  • This remains a local repository patch until the change is upstreamed into EmDash.
  • If emdash is upgraded, the patch may need to be regenerated or rebased.
  • The public renderer still supports legacy id-based blocks for backward compatibility, but new embeds should use slug.