The win32 tier is exactly the koffi IFileOpenDialog child process; any failure surfaces as-is. The pwsh -> Windows PowerShell 5.1 cascade, the shared WinForms script, and the triple-miss AggregateError are deleted: koffi is a packaged dependency whose availability the install guarantees, so no mechanism fallback exists (the browse backend remains the fallback at the composition level). The pwsh-first DPI picker-fix note is consolidated into a new simplification note recording the reversal.
The koffi IFileOpenDialog conversation runs in a spawned child process instead of a worker thread: the dialog is the child's first window, so Windows activates it without a foreground call, and a native fault stays contained to the child. The driver maps the child's message protocol onto a promise and services aborts by posting WM_CLOSE to the dialog thread's windows, killing the child when the close budget is exhausted. The built worker ships as lib/worker.cjs (the ./worker export) under plain node, and win32-dialog.spec.ts returns to the thread-safe pool.
The koffi redesign moved the dialog from a spawned child process (which
inherits a foreground-activation right from the spawning app) onto a worker
thread of the same process, so Windows shows the dialog without activating
it — it opens behind the app with a taskbar flash. The app has no native
HWND to hand the seam, so raise from the driver: on the 'showing' notice
(the worker posts it right before Show, before the dialog window exists),
attach this thread's input queue to the dialog thread's, call
SetForegroundWindow on its top-level window, and detach — retried on the
close cadence until the window appears, stopped on settle/abort/success,
never blocking the pick. Injectable seam mirrors closeThreadWindows; driver
tests pin the raise and its retry; the in-process note records the
mechanism (both languages, pairing re-recorded).
The driver's switch over Win32DialogWorkerMessage handled all three current
kinds but had no default, so a fourth kind added to the worker protocol
would compile cleanly and silently no-op — settle() never called and the
pick dangles until worker exit. Add the local assertNever backstop (the
command-compact shape; this package does not depend on dsh-llm for the
helper) and the return the error case needs to avoid falling into it.
Round-five review finding.
The @module header still described the Windows adapter as the pre-PR 'STA
PowerShell FolderBrowserDialog' while the README and Agent Notes document
the koffi IFileOpenDialog primary with the PowerShell chain as fallback;
mirror the README's platform summary.
- setThreadDpiAwareness checks SetThreadDpiAwarenessContext's return value
and cascades per-monitor-v2 -> per-monitor -> system-aware; DPI stays a
deliberate cosmetic best-effort - a host accepting none (or lacking the
API, pre-1607) still gets the modern dialog instead of a downgrade to the
legacy fallback chain over a cosmetic concern.
- The mocked-koffi world now uses a distinctive 4-byte pointer width and
rejects mis-sized out-buffers and mis-divided vtable offsets, so a
regression to hardcoded 8s fails the suite (the ia32 bug class).
- A keyless built-worker e2e guard loads lib/worker.cjs under plain
worker_threads on POSIX (the workflow-workerthread shape).
- The 'loaded lazily' module claims are reworded to attribute laziness to
the dynamic import('koffi') calls, and the discarded close-attempt
rejection is named at its catch.
Review round two on the in-process dialog:
- Vtable slots and out-pointers use koffi.sizeof('void *') instead of a
hardcoded 8 - win32-ia32 (which Node and koffi both ship) would have read
method pointers from the wrong address and crashed in-process before any
fallback could run.
- runFolderDialog pairs every successful (incl. S_FALSE) CoInitializeEx
with CoUninitialize in the outermost finally, releasing the dialog first;
a failed init is deliberately unpaired. Pinned across fake-bindings and
mocked-koffi suites.
- The abort close budget starts unconditionally: a worker hung before the
showing notice (koffi import or COM init) now ends in terminate instead
of a dangling promise; WM_CLOSE posting still waits for the thread id.
- A triple miss (dialog + pwsh + 5.1) surfaces an AggregateError carrying
all three causes - the in-process tier's reason was previously
unrecoverable from the final PowerShell error.
- The stray '=>{ ' formatter artifacts are normalized to real blocks.
Both stale note claims from the review are fixed: the DPI note's
Consequences no longer claims an ENOENT classification or zero new
dependencies, and the 2026-07-27 picker note's Windows bullet now names
the in-process primary and keeps the PowerShell chain as fallback (both
languages, pairings re-recorded).
The workspace files constraint keys worker bundles on the ./worker export
(lib/worker.cjs, the workflow-workerthread shape); the descriptive source
entry stays win32-dialog-worker.ts and tsdown renames the bundle.
The modern IFileOpenDialog becomes the primary win32 tier: a koffi-driven
COM conversation on a worker_threads worker (the modal Show never blocks
the host event loop), per-monitor-v2 DPI via SetThreadDpiAwarenessContext,
and abort service by re-posting WM_CLOSE to the dialog thread's windows,
with terminate+unref as the last resort (Node cannot interrupt a thread
blocked in native code, and such a worker must never hold the process open).
The PowerShell chain stays as the fallback tier with its trigger widened
from ENOENT to any pwsh failure, closing the review-flagged PowerShell 6
regression (no WinForms: exit 1, not ENOENT, so 5.1 never ran).
Layering keeps per-file coverage honest on every host: pure sequencing and
the driver test against fakes anywhere; the bindings run against a mocked
koffi COM world (the session-persistence-jsonl technique); POSIX hosts
drive the real spawn plumbing to its koffi-load rejection; win32 hosts run
a real open-and-abort-close smoke. The smoke joins processBoundTests: a
worker blocked in a native modal wedges the threads pool's teardown, while
a fork contains it. The worker bundles as its own CJS tsdown entry
(workflow-workerthread's pattern; no TLA), and the host module is imported
statically so the node-half bundle stays chunk-free.
Built-plane and real-COM behavior verified on native Windows: standalone
probes for the source worker, the built CJS worker, and the driver's abort
path all open and close the real dialog.
Agent Notes: new implemented/feature/2026-08-02-win32-in-process-folder-dialog
(bilingual) owns the decision; the DPI note is re-scoped to the fallback tier
it now describes and its AutoUpgradeEnabled attribution corrected (.NET Core
3.0 rewrote FolderBrowserDialog; the opt-out arrived in .NET 6).
.NET 10's modern FolderBrowserDialog renders Description as a bottom
strip above the folder input, and the 5.1 classic dialog as an unthemed
white box; the property is dropped entirely and a regression assertion
pins its absence.
The win32 branch now spawns pwsh.exe (PowerShell 7) first and falls back
to powershell.exe (Windows PowerShell 5.1) only when pwsh is missing
(ENOENT), mirroring the Zenity-KDialog fallback. PowerShell 7 renders the
modern IFileDialog folder picker; the 5.1 fallback keeps the legacy tree
functional. Both runtimes execute the identical script, which opts the
process into system DPI awareness (SetProcessDPIAware) before any window
exists, fixing the blurry bitmap-stretched dialog on scaled displays.
The construction-rollback + late-conflict-rollback + loud-rethrow block was
about to be a verbatim clone across the two flow packages; ui-slots now owns
it as deferGroupRegistration (one occupant, several holes, as a unit), with
direct specs for all three arms, and the native flow consumes it.
Holes declared after two flow providers activated left the loser throwing
out of the slot flush with partial occupancy. deferRegistration gains an
onFailure channel (late failures unsubscribe, then hand over instead of
throwing through the flush); the native flow's pair rolls back wholesale
and re-raises on the global channel the boot's fail-loud handler owns.
Duplicate rows of the SAME package stay silently idempotent (the component
identity guard skips an occupied hole).
- Directory-flow occupancy moves onto the inject face's reserved hooks
compartment: apply publishes a stable observable per surface and the
renderer binds useDirectoryFlow — no hand-rolled component subscriptions
(the client contract's channel for registrant-private reactive facts).
- The native flow's alive guard re-arms in effect setup: StrictMode's
development replay ran the cleanup once and every later outcome was
discarded.
- NativeDirectoryFlow moves to a package-internal module; ./client exports
only the Loader surface, tests import the internal module directly.
- The composition swap comment no longer advertises -browse as a complete
swap before its dialog lands (stacked follow-up).
An HMR replacement left the old instance's pick promise able to adopt a
second path through the shared owner callbacks; settlements now check a
component-lifetime ref (an injected-face identity change alone keeps the
pending settlement — the host-side dialog is unchanged, and the wire has no
per-request abort). Both settlement arms covered (ds-review-bot).
A declared-but-occupied second hole registers synchronously, so the pair
construction can throw after the first deferral installed its subscription;
that orphan then fires against the failed fiber's inactive context. The
effect now disposes already-created deferrals before rethrowing
(ds-review-bot on the browse twin; same shape here).
ui-workspace's two trigger surfaces each declare a single-kind directory-flow
hole (conversation.hero.workspace.directoryFlow / sidebar.workspaces.directoryFlow,
same owner contract) and keep only the trigger and the adoption: the Open-local-
folder entry renders while the surface's hole is occupied, and the occupant
reports one picked path per open through the hole's owner conversation
(open/busy/onPicked/onCancel/onError).
directory-picker-native becomes dual-face: its browser half fills both holes
with a renderless occupant driving host.pickDirectory, so the cordis.yml row
that mounts the backend also composes the client interaction — a mismatch is
impossible and a second flow package fails at client load.
With composition wiring both sides, the host.describe.directoryPicker
advertisement and the client's kind branching lose their last consumer:
the field, WorkspacesService.directoryPickerKind(), the DirectoryPickerKind
wire type, and the picker's per-open describe read are deleted. The connection
fixture now serves a deterministic pickDirectory path so the keyless snapshot
drives the full pick-then-adopt flow. ui-workspace's hand-rolled declaration
deferral is replaced by the deferRegistration helper it duplicated.
master's toolcall-open extracted runNativeCommand inside apiproxy for the
openPath opener while the picker seam had moved the native chooser (its other
consumer) into directory-picker-native; after the merge the two packages each
carried a verbatim copy. The runner now lives in packages/util/native-command
(zero-dependency library, per the util-group contract) and both native
integrations depend on it.
The browse interaction also presents a dialog (the in-app modal), so 'dialog'
failed to discriminate the two capability kinds; 'native' names where the
chooser runs. Package directory-picker-dialog -> directory-picker-native, kind
'dialog' -> 'native', with every seam/gateway/client/doc reference updated and
the seam Agent Note's naming rationale rewritten to match.
Huanqi Cao
creatixchu