[Steve-Mcl]

Related to #9 and node-red/node-red#5994

Summary

The main reason for this is working towards Vue and Vuetify support in Dashboard 2 (see #9 and https://discourse.nodered.org/t/weather-card-struggling-with-methods/85434/6?u=steve-mcl).

node-red/node-red#5994 adds JavaScript and CSS support to <script> and <style> blocks in Node-RED's HTML editors, which Dashboard 2's ui-template builds on. The JavaScript side uses monaco.typescript.getJavaScriptWorker(), which Monaco already exposes. There is no equivalent for CSS or HTML: Monaco has public worker getters for TypeScript and JSON (monaco.json.getWorker()) but not for CSS and HTML. So #5994 can only show CSS errors, not completion, hover or colour previews.

This adds the two missing getters, with the same shape as monaco.json.getWorker():

• monaco.css.getWorker(languageId = "css") for css, scss and less
• monaco.html.getWorker(languageId = "html") for html, handlebars, razor, and any language added with monaco.html.registerHTMLLanguageService()

Each resolves to (...uris) => Promise<worker> and rejects with "<languageId> not registered!" until that language has been used, because its worker starts lazily.

Changes

• generate-monaco-esm-i18n.js: new exposeLanguageWorkers() step after the copy. It patches cssMode.js / htmlMode.js so each language keeps its worker accessor, exports getWorker from register.js, and re-exports it from the older vs/language/{css,html}/monaco.contribution.js path.
  • Unlike the existing replacements, each patch must match an exact number of times or the build fails. A Monaco update that moves this code can't silently drop the API.
  • Gotcha for anyone touching it: replace-in-file counts matches with String.match(), so a non-global regex reports its capture groups as matches. patchExactly() makes the regex global before counting.
• test/browser/editor.test.js: new test. The API is present; an unused language rejects; CSS doComplete and findDocumentColors; SCSS doHover; HTML doComplete; and a language added with registerHTMLLanguageService(). It has its own timeout, because a worker that fails to start makes its calls wait forever.
• README.md: a note under Notes.

Testing

• npm run build: the patch applies cleanly against Monaco 0.57.0. editor.js grows by 720 bytes (4,985,273 to 4,985,993); the workers are unchanged.
• npm test 81/81, test:build output tier 85/85, test:browser 7/7 (6 before, plus the new one).
• Checked inside Node-RED with this build: the getters work, CSS completion and colours show up in #5994's <style> support, no console errors.

Notes

• This is stacked on Add tests #17 (tests), which is stacked on Bump 0.57.0 #16 (the 0.57.0 bump), so the diff here only shows this change.
• CI won't run on this PR as it stands: test.yml only runs for PRs into main and monaco-0.57.0. I can add a commit to include this PR's base, or we can just wait until it's rebased onto main.
• A language added with registerHTMLLanguageService() asks MonacoEnvironment.getWorkerUrl for a worker labelled with its own id. The test maps that label to html, which is what feat: add JavaScript and CSS support to script and style blocks in HT… node-red#5994 now does in Node-RED's getWorkerUrl.
• Worth considering offering upstream to microsoft/monaco-editor too, since JSON already has this. If it lands there, this patch can go in the bin.