Files
deepseek-harness/packages/fs/fs-local
Tianyi Cui b3f8b4c9c6 test(fs): close abort/concurrency/observed coverage gaps + with-key e2e
Behavioral gaps from the coverage audit (line coverage was already 100%; these
close BEHAVIOR gaps):

- fs-local: service-level writeText/editText pre-abort → FS_ABORTED (file
  unchanged); concurrent guarded-write race and mixed write-vs-edit race (one
  wins, one FS_STALE_VERSION, locks released); edit→edit version refresh at the
  provider; the replaceIfVersion post-write version matches a fresh stat. fsio:
  a mid-stream abort → FS_ABORTED (previously only pre-abort was covered).
- fs-policy: the agent-without-session owner rung ({agent:{}} → no owner →
  createIfAbsent / FS_NOT_OBSERVED); fs/write-intent first-wins (symmetric to
  the existing edit-intent test).
- tool-fs: abort-through-the-tool for read/write/edit (isError FS_ABORTED, file
  unchanged); a deterministic tool-tier concurrent-edit race via a shared read;
  the throwing-fs/observed contract (a throwing listener surfaces as isError but
  the mutation already hit disk); the replace_all edit message; parseReadArgs
  rejects fractional/NaN offset and zero/negative limit.
- dsh-fs: FsError chains a cause through ErrorOptions.

New with-key e2e (packages/fs/tool-fs/tests/fs-tools.e2e.ts, self-skips without
DEEPSEEK_API_KEY): a real model drives the real read/write/edit tools to create
→ read → edit a file, verified on disk; a second test proves a relative path
resolves against the per-session cwd (factory meta.cwd) not config.cwd. Booted
via a plain tests/harness.ts. Added dsh-agent-loop + dsh-llm-deepseek devDeps.
2026-07-02 20:38:06 +08:00
..

@deepseek-ai/dsh-fs-local

The local-filesystem implementation of the ctx.fs provider seam (@deepseek-ai/dsh-fs). Backs the six FileSystem primitives with the host filesystem; loading it as a plugin populates ctx.fs.

import { LocalFileSystem } from '@deepseek-ai/dsh-fs-local'

await ctx.plugin(LocalFileSystem, { cwd: process.cwd() })
// ctx.fs is now the local backend; load @deepseek-ai/dsh-fs-policy for the
// freshness policy gate and @deepseek-ai/dsh-tool-fs to expose read/write/edit.

Behavior

  • resolve(path, opts?) — a relative path resolves against opts.cwd when the caller supplies one (the model-facing tools pass the calling agent's session cwd — see the per-session cwd RFC), else config.cwd (default process.cwd()); an absolute path ignores both. The targetKey is the file's realpath, so two input paths reaching the same file through symlinks share one identity, and writes/edits land on the link target (preserving the link). A not-yet-existing path uses the realpathed parent directory plus basename when the parent exists; only an unresolvable parent falls back to the absolute path. displayPath is the absolute (un-resolved) path.
  • stat — returns FsInfo (version = mtimeMs:size, type of file/directory/other, byte size) or undefined when the target is absent.
  • readText / streamText — UTF-8 only. readText reads the whole file; streamText streams it in chunks (cross-chunk decoding) so a huge file never has to be held whole in memory. Both reject invalid UTF-8 and NUL-byte binary samples (FS_NOT_TEXT) and non-regular targets. The read tool (@deepseek-ai/dsh-tool-fs) decides which to call by size and owns the line windowing.
  • writeText — atomic: writes to a temp file opened exclusively (wx, 0o600) inside a randomly-named private staging dir (0o700) next to the target, fsyncs, then renames over the target. An existing file's mode is preserved, while new files default to 0o600. The expected guard is OPTIONAL: omitting it unconditionally creates-or-overwrites; createIfAbsent creates a missing target and rejects an existing one (FS_NOT_OBSERVED); replaceIfVersion replaces only at the observed version (a missing target or mismatch is FS_STALE_VERSION).
  • editText — atomic literal read-modify-write over the same primitive, serialized per target by a mutation lock. The expected guard is OPTIONAL: when supplied it verifies the version BEFORE literal matching (a stale edit reports FS_STALE_VERSION, never FS_EDIT_NOT_FOUND/FS_AMBIGUOUS_EDIT against newer content); omitting it edits the current content unconditionally. A missing target reports FS_STALE_VERSION either way. LF-normalizes for matching, restores the file's dominant CRLF/LF style, and rejects empty oldString / zero matches (FS_EDIT_NOT_FOUND) or ambiguous multi-matches without replace_all (FS_AMBIGUOUS_EDIT).

cwd is not a sandbox

config.cwd is a resolution default, not a containment boundary — absolute paths and .. escape it. Enforce containment with a stricter ctx.fs backend or a permission plugin on the tools/execute waterfall. See the filesystem capability-seam RFC's Risks section.

The raw I/O lives in src/fsio.ts (Cordis-free, independently unit-tested); src/index.ts is the thin service wiring.