dsh-file-preview

Workspace file-preview host half: a Typert Remote (filePreview) that lists the workspace tree, reads/writes text files, and resolves the preview theme and config for the browser half.

The browser UI lives in a separate package: @undeadsheep/dsh-client-ui-file-preview.

Remote surface

Method	Request	Result
listDir	{ sessionId, path }	Ok<FileTreeNode[]> | Rejected
readFile	{ sessionId, path }	Ok<{ path, content }> | Rejected
readImage	{ sessionId, path }	Ok<{ path, mimeType, data }> | Rejected
writeFile	{ sessionId, path, content }	Ok<{ path }> | Rejected
readTheme	{ sessionId }	Ok<{ colors, bg, fg }>
readConfig	{ sessionId }	Ok<{ indentSize, useTabs, pollInterval, fontSize }>

Business results use the repo's { ok: true, value } | { ok: false, error: { code, ... } } convention; the generated ./remote face wraps them in the RemoteResult carrier. Wire codecs are generated from the @Remote method types by typert codegen — there is no hand-written schema file.

listDir lists a single directory (path = '' for the workspace root) and skips heavy/noise directories (node_modules, .git, .next, .ssh, …) plus sensitive filenames (.env*, id_rsa*, *.pem, *.key, …). A single listing is capped at 1000 children. Dir nodes carry empty children, which the browser half fills lazily by calling listDir again when a directory is expanded. readFile / readImage / writeFile also refuse those sensitive paths, so typing them in Quick Open does not bypass the tree filter.

Config

Key	Default	Meaning
maxFileBytes	2097152	Maximum UTF-8 byte length the preview will read or write
maxImageBytes	5242880	Maximum byte length of an inline image the preview will read

Workspace config files (read per Session, optional)

• preview.config.json — indentSize, useTabs, pollInterval, fontSize (with .prettierrc / package.json#prettier fallback for indent knobs)
• preview-theme.json — keyword, string, number, comment, tag, function, type, variable, background, foreground
• .vscode/settings.json — editor.tokenColorCustomizations and workbench.colorCustomizations are read as a fallback theme

Known limitations

• Preview is text-only (plus raster png/jpeg/gif/webp); binary, SVG-as-image, or oversized files return not-text / too-large. A stat with no size is refused rather than reading the whole file into memory. Writes use the same byte cap as text reads.
• listDir returns at most 1000 children per directory.
• Symlink following after resolve is the host ctx.fs implementation's responsibility; this plugin re-resolves search children against workspaceRoot but cannot realpath on its own.
• Syntax highlighting is a lightweight hand-written tokenizer (not highlight.js / TextMate), and a prettier engine cannot be embedded.
• Auto-refresh is polling (pollInterval, clamped 500–60000 ms), not a real file watcher.