dsh-plugin-live-diff

dsh-plugin-live-diff

Live streaming diffs for DSH file edits — a diff that grows while the model is still emitting the call, instead of appearing all at once when the tool call settles.

中文说明 →

┌ Live Diffs ─────────────────────── 1 in flight ─┐
│ solar/viewport.py                     python    │
│ 403  + def zoom_by(self, steps, anchor_x=None): │
│ 404  +     world_x, world_y = self.to_world(…)  │
│ 405  +     self.zoom = clamp_zoom(…)            │
│ 406  +     self.offset_x = anchor_x - …    ▌    │
└─────────────────────────────────────────────────┘

Demo

A 26-second demo on Bilibili — "deepseek v4.1 flash 太强大了 50元手搓文件变更实时预览"
Live Diffs for DSH — 边写边看的编辑过程

The problem

DSH already ships a diff card, and it already accumulates the streaming data — the host does argsRaw: base.argsRaw + chunk.argumentsDelta for exactly this reason. What it lacks is a reader that tolerates a half-arrived argument string:

// dsh-client-ui-tool
value = JSON.parse(call.argsRaw);          // throws on a truncated document
if (typeof oldText !== "string" || typeof newText !== "string") return null;

While a call streams, argsRaw is a truncated JSON document, so the parse fails and the card stays empty until the final token lands. This plugin supplies the tolerant reader, and a surface to put the result on.

What it does

• Floating panel (Live Diffs) that patches the diff in place as characters arrive. Width is draggable from its left edge and remembered across reloads.
• Chat transcript card for edit / write, rendered through DSH's own DiffBlock primitive so it matches the shell's diff cards by construction.
• Tolerant reader over partial JSON: a field whose value string is still open comes back usable-but-incomplete instead of null.
• Partial syntax colouring with per-language profiles (Python, JS/TS, JSON, YAML, shell, Markdown).
• The panel keeps the newest line in view while streaming, and stays on screen after the edit finishes rather than blanking the moment entries empties.
• A finished edit is not re-rendered row by row — the DOM is patched incrementally, so a line's fade-in plays once instead of restarting on every poll.

It replaces rendering only. It writes nothing to your files and modifies no other package.

Requirements

Built and verified against DSH 0.1.5-rc.1 on Windows (cordis 4.0.2, dsh-api-session-controller 0.1.5-rc.2).

This plugin talks to DSH through its internal client surfaces, not a published extension API. Nothing here is versioned or guaranteed:

What it relies on	Used for
ctx.sessions client service	reading the session event window — the only source carrying streaming tool-call-delta chunks
ctx.slots / ctx.sidebarRightTabs	registering the transcript card and the sidebar tab type
@deepseek-ai/dsh-client-ui-primitives (DiffBlock)	the chat transcript card
ctx.webServer + ctx.clientModules	the host-side /live-diff-diag route
keyed tool.call.toolview entries for edit / write	replacing the shipped FileMutationRow for those two tools

That last row is the sharpest edge: a keyed registration replaces the shipped row, so this plugin deliberately overrides a component DSH ships. A DSH upgrade that renames the tool keys, changes the toolview contract, or restructures the session event window will break it — most likely by showing an empty panel rather than by raising an error.

If you are on a different DSH build, try it and read the diagnostics (below); the panel reports what it can and cannot see rather than failing silently.

Install

Two pieces, both outside DSH's own files.

1. Make the package resolvable under the active profile's node_modules. A junction/symlink, not a file: specifier — the Loader does not resolve those.

:: Windows
mklink /J "%DSH_HOME%\profiles\node_modules\dsh-plugin-live-diff" "C:\path\to\dsh-plugin-live-diff"

# POSIX
ln -s /path/to/dsh-plugin-live-diff "$DSH_HOME/profiles/node_modules/dsh-plugin-live-diff"

2. Add a row to the profile's user patch layer, profiles/web/cordis.patch.yml:

- insert:
    - id: live-diff
      name: dsh-plugin-live-diff

3. Restart dsh web. A running process does not pick up a new package; the row has to be seen at startup. After that, edits to the plugin are picked up live (patchReload: live), but client-bundle changes still need a restart plus a hard refresh (Ctrl+Shift+R) — a plain refresh has served a stale bundle.

Verify it works

node test/run-all.mjs

That runs six suites and prints one line each:

Suite	What it covers
parser.test.mjs	the tolerant reader, truncating a real tool call at 25 points
apply.test.mjs	registration, plus layout and manifest guards
host.test.mjs	the diagnostics route end to end, without a server
highlight.test.mjs	language detection and tokenising
overlay.test.mjs	incremental DOM patching, resize, scroll, the finished state
audit.mjs	static audit of the bundle: dead helpers, duplicate declarations, require() specifiers missing from dsh.client.inject

All six exit 0. Then make the model edit a file and watch the panel. If it stays empty, the panel's own diagnostics footer and the host log say why — see below.

Diagnostics

The author cannot open your browser, so the panel reports on itself. It POSTs a one-line reading to /live-diff-diag on every change, and the host half appends it to a log file:

• default: /dsh-plugin-live-diff/diag.log
• override: the DSH_LIVE_DIFF_LOG environment variable

Each line carries the event-window counters and a compact event sequence:

{"surface":"overlay","entryCount":1,"deltaCount":269,"accumulating":1,
 "sequence":"b0) t0)x269","toolNames":["write"],"reason":"deltas present"}

sequence collapses runs of the same chunk type per stream index, which is how the arrival order was confirmed: block-start always precedes that index's deltas.

The panel does not overwrite document.title. It used to; a title is only visible while its tab is inactive, which is the one moment nobody is watching a live diff.

Design notes

The reasoning behind the non-obvious decisions — why the panel is plain DOM rather than React, why the sidebar was abandoned, why Cline's components were not ported, the measured transport granularity, and the layout traps that shipped twice — is in docs/DESIGN.md.

Credits

Behaviour (not code) was informed by Cline's streaming diff: degrade to what has arrived rather than bailing, infer "still streaming" from the document not being closed, and pin the view to the newest line. Details in the design notes. Cline is Apache-2.0; no Cline code is included here.

License

MIT