dsh-editor

dsh-editor (alpha.13)

A CodeMirror 6 tab type for the pack's right bar (dsh-rightbar) that opens text files editable. It registers the id dsh-editor and the kind editor through the bar's own tab-type registry, with its body and chip title in the keyed sidebar.right.pane.tab / sidebar.right.pane.tab.title seats and a guide entry at order: 20 for the "+" control. It is text-only (strict UTF-8, binary refused), starts blank documents, and writes through authenticated Node routes because remote.workspaceFiles exposes no mutation operation.

What it adds

• Text files open editable. patterns: ['dsh-resource://file/**'] in the extension band, which outranks every shipped viewer, with a canOpen that vetoes what a text editor has nothing to add to (.html, images, PDF, office/archive/media, binary) and paths outside the session workspace, including the session-less absolute/… form.
• Markdown is claimed too (.md, .markdown, .mdown). The toolbar's Preview button reads the shipped document preview's kind out of the tab registry (never hardcoded) and calls ctx.get('sidebarRight').openResource(address, { kind, replaceTab }), so Edit ⇄ Preview is one tab on the same file. It is refused while the document has unsaved edits, because the preview reads from disk.
• "+" → Editor opens a blank document. Save (or Ctrl/Cmd+S) asks for the file name with its extension through the shared dsh-modal modals service and creates it in the conversation's workspace folder; the parent folder must already exist and a taken name answers 409 EXISTS inside the dialog.
• Saving is optimistic and atomic. The panel PUTs the whole document with the mtime/size it opened with, and a file that moved on disk offers Reload / Save anyway rather than a silent clobber. Unsaved work is lost on tab close or restart.
• The language map. Every extension is mapped in languageExtensionFor and every lookup goes through a guard, so an engine older than the bundle opens the document unhighlighted rather than killing the tab. Lezer factories (function shape) via engineLanguage cover javascript (js/mjs/cjs/jsx/ts/tsx), json (json/jsonc), markdown (md/markdown/mdown), python (py/pyw), html (html/htm/xhtml), css and yaml (yaml/yml). CM5-style StreamParser objects (found by their token(), via engineStreamMode) cover shell (sh/bash/zsh/ksh/dash), powerShell (ps1/psm1/psd1), batch (bat/cmd, from the pack's own vendor/batch-mode.js), rust (rs) and toml (toml) from the vendored @codemirror/legacy-modes. Each returns null plus one console warning naming the missing factory and the rebuild command, so languageExtensionFor has no direct CM.(...) call.
• The palette follows the app's theme: oneDark only while the app is dark, a token-driven transparent light layer otherwise, switched live through a CodeMirror Compartment reconfigured off ctx.get('theme') / theme/change, with body[data-ds-dark-theme] as the fallback. Both theme services are resolved lazily.
• The rendered Markdown body is shadowed. The keyed sidebar.right.tab.document slot is registered at priority: -10 (lowest renders), so only the page body is this package's while the shipped preview keeps its chrome; uninstalling brings the shipped body back. That body carries an Edit pill back to the editor and undoes what the preview's plain-text scrollport imposes (white-space:pre and the mono stack).

How it plugs in

Route	What it does
GET /api/dsh-editor/file?session=&path=	read one text file (strict UTF-8, no NUL, ≤ 2 MiB; HEAD answers headers and no body)
PUT /api/dsh-editor/file	save {session, path, text, expected?: {mtimeMs, size}} - atomic temp+rename, 409 when the file moved on disk
PUT /api/dsh-editor/file with {create: true}	create a file: the parent must exist inside the workspace and is realpath-checked, the target must not exist - 409 EXISTS, create-exclusive
GET /api/dsh-editor/vendor?v=	the vendored CodeMirror 6 classic bundle (window.DSHEditorCM), fetched lazily on first open

The workspace root is resolved host-side (live session header first, session persistence second, typed NO_WORKSPACE otherwise) from the session id the tab's address already carries, dsh-resource://file/session// ; the client never names a root. The engine request is version-qualified, and the route answers cache-control: no-cache over a content-hash ETag, re-stating the artifact per request, so a rebuild needs no restart.

Limits

• Text only: strict UTF-8, no NUL, ≤ 2 MiB read and save.
• No folder browser and no binary editing; canOpen refuses any address outside a session workspace.
• Create-on-save, never overwrite: a create is create-exclusive.
• Unsaved work is lost on tab close or restart.

Verify

node scripts/checks/check-client-bundles.mjs
node scripts/checks/check-node-routes.mjs

check-client-bundles.mjs drives the browser half through a real React runtime: the registration and guide order, the seats, the shadowed document body, the language-map guard and the Preview hand-off. check-node-routes.mjs drives the routes against a scratch workspace.

Install

The launcher (scripts\setup\install.bat / ./scripts/setup/install.sh) auto-discovers the package as a standard dsh.bundle, and the uninstall twins do the same. It is a live link in the web profile, so code edits need a restart of npx @deepseek-ai/dsh web plus a hard refresh.