dsh-shell-host

DSH bundle: the host-plane shell executor replacement layer for Windows — a replacement of the built-in platform shell executors with pluggable backends (msys2 default, plain, pwsh; wsl reserved), plus a Plugins-page settings card. MSYS2 is the default backend, not the bundle's identity.

Positioning: MSYS2 is an ENVIRONMENT independent of any one shell — install root (msysRoot), subsystem (MSYSTEM), PATH surface, pacman/cygpath tooling are first-class; bash is just the environment's configurable shell binary. The executor inside is a fork/generalization of @deepseek-ai/dsh-bash-local (0.2.0-rc.2) with an identical external interface — same bash tool schema, jobs, spill files, exit markers, and configForms namespace shape — so every preset's tooling works over it unchanged.

What the bundle does (host replacement)

cordis.patch.yml operates on the HOST plane (applies to every preset):

1. Disables the base bundle's platform executors on Windows: pwsh-sandbox (yields the platform-shell role) and bash-sandbox (re-stated; its win32 bash -c would hit the C:\Windows\System32\bash.exe WSL stub anyway).
2. Inserts this package's executor as ctx.shell (row id shell-host; backend configurable: plain / msys2 / pwsh, default msys2 with subsystem UCRT64 — pwsh landed in #3 / D7 phase 1.5, wsl reserved). Every preset's tool-bash resolves the host seam — Matt 工作流, shipped presets, anything bash-dialect.
3. Overrides terminal-controller (the right-sidebar USER terminal): MSYS2 bash --login -i becomes the default shell with a visible name, and the bare bash candidate is pruned (host PATH has no MSYS2, so it can only resolve to the WSL stub). Install-probed: no MSYS2 → upstream discovery stands.

All rows carry win32 guards; on POSIX the bundle is dormant.

Host MSYS2 prerequisites（宿主环境最低工具集，2026-10-02 实测补齐）

本 bundle 只把 shell 缝绑到 MSYS2 bash——不负责装齐 MSYS2 工具链。裸 MSYS2 缺 常用工具会让 agent 的验证手段悄悄降级（实测：diff/cmp 缺失时所有 diff 类验证被迫 绕 git diff --no-index）。安装后请补齐：

pacman -S --needed diffutils patch jq unzip rsync

判定方法：agent 会话里 command -v diff 落空即缺。新增工具需求时在此处追加清单。

Known trade-off: web-app's standard/minimal presets enable the pwsh tool on win32; after the replacement its command text is handed to bash (the seam has no dialect translation, by upstream contract). Use bash-dialect presets on deployments with this bundle.

VS Code-modeled internals

Backend descriptors (src/backends.ts) mirror VS Code terminal profiles: ordered executable candidates (ITerminalExecutable), per-mode argv templates (IShellLaunchConfig), profile env (MSYSTEM, CHERE_INVOKING=1 so login shells keep the working directory), and addEnvMixinPathPrefix-style PATH prefixing. Detection (src/detect.ts) follows VS Code's probe order with the WSL System32 stub excluded, and fails loudly naming every probed location.

Front-end settings page

src/client/ ships the browser half (served as /plugins/dsh-shell-host/client.js): a Plugins-page card (order 11, after the stock Shell card) bound to the shell-host configForms namespace — backend, subsystem, install root, bash path, plus the command budgets. Values write through the settings user-section and re-apply to new commands without a reload (all config fields are volatile). The bundle's lib/client.js is a closure-factory artifact over the platform module table (requires only @deepseek-ai/dsh-client-ui-primitives and react/jsx-runtime).

Provenance (fork baseline, T1)

• Forked from @deepseek-ai/dsh-bash-local 0.2.0-rc.2 (© DeepSeek AI, MIT; see LICENSE). Source: upstream monorepo tag dsh-v0.2.0-rc.2, commit 639ed01539 (packages/shell/bash-local). Between 0.1.7-rc.2 and 0.2.0-rc.2 this package's src/tests are byte-identical (only the version field moved); baseline = what the local desktop (0.2.0-rc.2) runs.
• Functional deviations: src/index.ts is upstream verbatim; src/backends.ts / src/detect.ts are this repo's extensions (backend registry plain/msys2/pwsh + wsl-reserved, pwsh probing — #3 / D7 phase 1.5), beyond upstream. Ported-test deviations (mechanical only, both documented here):
  • tests/executor.spec.ts imports LocalBashExecutor from ../src/index.ts instead of the upstream package name (the package here is dsh-shell-host).
  • tests/settings.spec.ts imports live-config.ts from ./helpers/ — the helper is ported verbatim from upstream packages/settings/settings/tests/live-config.ts.
• Dependencies: @deepseek-ai/* packages are never fetched from npm. Typecheck/build/tests resolve them against the local upstream monorepo checkout (../deepseek-harness, pinned to tag dsh-v0.2.0-rc.2): tsc via the inherited tsconfig.base.json paths map, vitest via explicit source aliases, tsc -b-built declarations for the declaration emit, and pnpm link: overrides so the installer never touches the registry for the scope. Tooling (typescript/vitest/tsdown) comes from npm.

Status: v0.1.x — host-plane replacement + settings page + pwsh backend (505be8e, #3 phase 1.5; typecheck both facades, vitest 53 passed | 1 skipped, win32 live E2E green). See CONTEXT.md and GitHub Issues for the plan.