The mocked process.send consumed vitest's own fork-pool IPC messages and immediately ran the post callback, whose disconnect() severed the test worker's channel (process.connected is true under forks) — the whole spec's results vanished and win32-dialog-bindings.ts/win32-dialog-worker.ts fell to near-zero coverage on CI. The mock now records without invoking the callback or disconnecting; the real close lifecycle stays with built-worker.e2e.ts. Verified under both the threads and forks pools.
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.
- 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 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).
