Sveltia 0.250.0 compatibility

Tracking: #347, part of #342.

Released API

Sveltia 0.250.0 is the minimum released version with the bound native serialization callback. The preceding 0.249.0 release does not expose FileFormatterContext or serialize in its published declarations. The npm 0.250.0 tarball was published at 2026-10-21T00:19:35.690Z (October 20 in New York), with integrity:

sha512-VDdYsC2zSiXGGvzgPIJMVyG9Yf3JsAFXr6OltZZnv7kTANHeOVS1hjuorUfa472rWO40l1bheKPOhEFtpdoNtg==

The published types/public.d.ts declares FileFormatter(value, { serialize }), where serialize(value) returns a Promise<string>. Register under a built-in format name with registerCustomFormat(name, extension, { toFile }). The native callback keeps the entry’s output options, front matter delimiters, and field comments; it copies the supplied content before removing the body. It does not accept the second format argument available in the earlier local prototype. Returned custom output is trimmed and receives a trailing newline.

Save and failure evidence

The executable probe uses Forge’s built content-model and Sveltia adapter to create its collection, and loads the installed, released CMS browser bundle. It uses an isolated browser origin and the local repository backend backed by browser storage. Article content never leaves the browser. It checks metadata edits, raw Markdown edits, rich text edits, custom front matter delimiters, callback promise rejection, synchronous callback exceptions, and a native YAML serialization error caused by a function-valued property.

Successful saves retain model-derived title, description, tags, draft, and body content. Native serialization leaves the callback’s input object unchanged. Failures surface an error dialog, preserve the original file byte for byte, and retain the edited description in the open editor. Sveltia awaits callback completion and does not fall back to saving unformatted content. Dismissing the error and retrying with a successful callback permits saving the retained edit. This clears the upstream fallback concern for the tested version and backend.

Reproduce after installing root and template dependencies and Playwright’s Chromium browser:

npm run build --workspace @rm-industries/content-model
node packages/browser-oxfmt/test/sveltia-serialization.ts

The first optional argument is an installed Playwright module path; the second is a Playwright browser channel, e.g. chrome. This allows an existing local browser installation without adding a root browser dependency. The probe asserts CMS 0.250.0 so a future upgrade must update this evidence deliberately.

Compatibility release and adoption

Content-model 1.1.9 is a compatibility-only patch. The peer range preserves >=0.193.2 <0.246.0 and adds >=0.250.0 <0.251.0. Unverified versions 0.246–0.249 remain excluded. This deliberately narrows the continuous-range proposal produced by peer:prepare; the adapter’s API and runtime stay intact. Existing consumers need no migration. Consumers needing native serialization must install Sveltia 0.250.0 with content-model 1.1.9 after publication.

Local validation uses Node 26.9.0 on macOS and the committed npm lockfile: content-model’s 32 tests, type checking, build, and workspace pack dry run. The local pack identity is rm-industries-content-model-1.1.9.tgz; regenerate its integrity from the dry-run JSON after validation.

Run the validation above before using --ignore-scripts, which keeps the packing JSON free of test/build output. The release plan can be generated from the dry-run JSON with:

npm pack --dry-run --ignore-scripts --json --workspace @rm-industries/content-model > /tmp/content-model-pack.json
npm run release:prepare -- --package content-model --sha "$(git rev-parse HEAD)" --pack-result /tmp/content-model-pack.json

The root dependency audit currently reports seven advisories, including the existing markdown-it high severity advisory GHSA-gfr2-rv44-r23c. The affected dependency is unchanged by this compatibility update. Publication remains blocked until the release security gate passes.

This prepares a content-model-v1.1.9 release identity; it neither creates a tag nor publishes. The protected release workflow dry run, maintainer review, publication, registry integrity/provenance verification, and verified published-* handoff remain required by release policy before template adoption. No formatter hook, formatter dependency, or template version change belongs to this compatibility patch.

The save probe does not cover remote Git backends, Safari, or every supported Node line. Their existing CI and integration gates remain required; the local repository result establishes serialization failure behavior, not a blanket browser or backend certification.