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.
The ACP bridge gives each session its own workspace (SessionHeader.cwd), and
dsh-tool-bash already resolves a bash workdir against it. But ctx.fs.resolve(path)
took no caller context and dsh-fs-local resolved every relative path against a
fixed config.cwd (process.cwd() at plugin load) — so in the ACP demo `write
foo.txt` and `bash cat foo.txt` hit different directories the moment an editor
opens any project other than the server's launch dir.
Thread the session cwd into resolution, mirroring dsh-tool-bash: widen
FileSystem.resolve to resolve(path, opts?: { cwd?: string }); dsh-fs-local bases
a relative path on opts.cwd ?? config.cwd (absolute paths ignore it); the
read/write/edit tools derive it via a shared sessionCwd(exec) helper
(exec.agent?.session.header.cwd). The provider stays free of dsh-agent/dsh-session
— the tool projects exec → cwd and hands over a plain string, per the
explicit-at-seams convention. Backward compatible (the arg is optional).
Tests: fs-local resolve(path,{cwd}) bases relative on the passed cwd / ignores it
for absolute; tool integration writes/reads/edits in a session cwd != config.cwd
and verifies the file on disk (proven to fail on the pre-fix no-cwd path). Fakes
that stood in a bare {session:{}} now carry a header so sessionCwd doesn't throw.
RFC in docs/rfc/implemented/architecture/2026-07-02-fs-per-session-cwd.md.
Rename per review naming decisions:
- package dsh-file-context → dsh-fs-policy (dir, package name, plugin name,
tsconfig refs, importers, type-equiv manifest, generated catalog + module-graph)
- events fs/write-expectation → fs/write-intent, fs/edit-expectation → fs/edit-intent
(fs/observed unchanged); type FsWriteExpectation → FsWriteIntent, "expectation"
wording → "intent" throughout
- exported FileContextExec → FsPolicyExec
Make the implemented RFCs describe what shipped, not the superseded designs:
the 2026-06-17 capability-seam + tool-schemas RFCs no longer place policy on
ctx.fs or use full/partial-view authorization, and the fsspec RFC's ctx.fileContext
service prose is rewritten to the fs/* event-gate reality (freshness-based auth).
Sharpen docs/rfc/implemented/AGENTS.md: a rename is a fact to fix IN PLACE — the
"new RFC" escape hatch is for macro decision reversals only, not renames.
Code fixes from review:
- fsio.ts resolveLocalTarget/probe translate ENOTDIR (a parent path segment is a
file) into the structured FsError taxonomy instead of leaking a raw Node error;
resolve reports FS_NOT_FOUND, probe reports absent. Regression tests proven to
fail on the unfixed code.
- tool-fs HMR test now asserts prompt sections (not just tool schemas) are
withdrawn on disposal.
- fs/observed is a plain (unguarded) ctx.emit: correct the fs-policy comment,
filesystem.md, and tool-fs module doc that wrongly claimed the tool "contains"
a throwing listener; a throw surfaces as the tool's isError result.
- drop the false "loaded by the default product config" claim (no config wires
the fs tools yet), the duplicate ctx.bash service-map row, the stale
FileReadRequest catalog link-map entry, and the fs/fs README EOF blank line;
correct the dsh-fs package.json description.
Two cohesion cleanups on the filesystem tool package:
- Fold window.ts + types.ts + formatReadOutput into one cordis-free
read-render.ts. Line windowing, the FileReadOutcome shape, and output
formatting are one concern (the read tool's rendering); splitting them across
three files added no value. read.ts is now just the tool (schema + I/O).
- Drop observe.ts and emit fs/observed with a plain ctx.emit in read/write/edit.
The event is contractually a synchronous, side-effect-only recorder
(file-context's listener is a WeakMap.set), so the per-call try/catch guarded
against a contract violation that cannot happen under the shipped listener —
defensive code for an impossible case. The event contract (dsh-fs JSDoc,
README, RFC) is updated to state the fire-and-forget semantics plainly.
Adapt the four fs packages to master's single-tsconfig build convention
(lib/types outDir + types path + files allowlist), brought in by the merge.
While doing so, drop dsh-tool-fs's /read//write//edit subpath plugins. They
were the only subpath-export package in the tree and forced bespoke tsdown,
tsconfig path, package.json files, and workspace-constraint handling that no
sibling tool package (e.g. dsh-tool-bash) carries, for a focused-deployment
use case no consumer needed. dsh-tool-fs is now a single root plugin that
registers read/write/edit, mirroring dsh-tool-bash; the per-tool registration
helpers stay internal modules the root composes. The file-context event-gate
RFC is amended to record the narrowed scope.
Invert the tool↔policy control flow per the file-context event-gate RFC.
dsh-tool-fs becomes the executor — it reads/writes/edits through ctx.fs
directly, owns read windowing, and dispatches fs/write-expectation /
fs/edit-expectation (single-slot waterfalls) plus a contained fs/observed
emit. dsh-file-context drops its ctx.fileContext service and becomes a pure
event-gate plugin (observed-state + read-before-edit + version-guarded
write/edit, decided on those events). The provider's version guard becomes
optional so ctx.fs alone is a complete unconstrained text-storage seam:
removing the policy plugin gracefully loses the policy instead of breaking
the tool at a service-injection boundary.
Implements the split-the-filesystem-seam RFC. ctx.fs shrinks to a text-storage
provider seam (resolve/stat/readText/streamText/writeText/editText with branded
FsTargetKey/FsVersion and an explicit FsWriteExpectation); the new
dsh-file-context package owns the model-facing policy (read windowing,
observed-state, write/edit freshness) as the concrete ctx.fileContext service.
Authorization is now freshness-based rather than full/partial view: a windowed
read records the file version and authorizes a later edit when the file is
unchanged, removing the dead-end where reading lines 100-150 of a large file
could not edit line 120. editText stays a provider primitive so version guard +
literal match + atomic rewrite remain one critical section, and the stale check
runs before matching so a stale edit reports FS_STALE_VERSION. tool-fs injects
fileContext, never reaching around to ctx.fs (the no-bypass contract).
Tianyi Cui
Dudu-0223