dsh-lsp-swift

dsh-lsp-swift

Swift language configuration pack for DeepSeek Harness (DSH). sourcekit-lsp — the Swift language server shipping with the toolchain. 中文：DSH 的 Swift LSP「即插即用」语言包 —— 装上本包，.swift 文件即可用 lsp 工具做代码导航。

This pack is one Cordis configuration plugin: it registers a configured @deepseek-ai/dsh-lsp-stdio instance on ctx.lsp with the server command, launch arguments, and extension mapping for Swift. It implements no LSP protocol — the shared base does: @deepseek-ai/dsh-lsp (the seam) + @deepseek-ai/dsh-tool-lsp (the model-facing lsp tool with goToDefinition / findReferences / goToImplementation / hover). Twelve packs reuse one unchanged base.

Installing the language server

sourcekit-lsp ships with Xcode and with the Swift.org toolchains, for example:

/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/sourcekit-lsp

Add that directory to PATH (or run xcrun --find sourcekit-lsp to locate it). No separate install step exists for Xcode users.

⚠️ The plugin itself never downloads or installs the server binary — matching the upstream anthropics LSP plugins, the server is an external prerequisite. The plugin only resolves and launches it.

Supported extensions

| .swift | swift |

How the pack works

• Lazy start: the server process is not started at load. lsp-stdio launches it lazily on the first matching query and keeps one process per workspace.
• No-server fallback: if the executable cannot be resolved, the pack still loads; every lsp query for these extensions fails with a structured LSP_UNAVAILABLE error naming the command — the rest of the session is unaffected.
• Config overrides: every default below can be overridden from the composition row, e.g. a server installed at a non-standard path:

- id: lsp-swift
  name: '@dsh-lsp-packs/dsh-lsp-swift'
  config:
    command: /absolute/path/to/sourcekit-lsp
    args:
      - --stdio
    extensionToLanguage:
      '.xyz': custom-language-id
    maxDocumentBytes: 8000000

All fields of the servers table documented in the @deepseek-ai/dsh-lsp-stdio README are accepted (command, args, env, extensionToLanguage, initializationOptions, configuration, byte/time bounds).

Mounting

1. Mount the shared base once (the lsp service, the lsp tool, and a filesystem/subprocess pair for the same execution world) — ready-made snippet in examples/base-composition.cordis.yml of the dsh-lsp-packs repo.
2. Install the pack (its cordis.yml is the dsh.bundle.patch, so the row inserts itself):

dsh plugin add @dsh-lsp-packs/dsh-lsp-swift    # published name
dsh plugin add /path/to/dsh-lsp-packs/dsh-lsp-swift  # or a local checkout

or compose the row directly (name resolved from the installed package):

- insert:
    - id: lsp-swift
      name: '@dsh-lsp-packs/dsh-lsp-swift'

Smoke test

pnpm vitest run --dir dsh-lsp-swift   # or from the repo root: pnpm test

• Lane 1 (offline): asserts the defaults (command / args / extension table / provider id).
• Lane 2 (offline): asserts the missing-server fallback returns LSP_UNAVAILABLE.
• Lane 3 (needs the server): runs the four lsp operations against Sources/sample/sample.swift; it auto-skips when sourcekit-lsp is not on PATH.

The smoke test writes a minimal SwiftPM package (Package.swift + Sources/sample/) so sourcekit-lsp can serve references and protocol implementations; the protocol area() gives goToImplementation a real struct Circle target.

License

MIT — see LICENSE. The server binary is a third-party component with its own license.