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fix(prelude): resolve symlinks consistently in classic and SEA modes - #296
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Codecov Report✅ All modified and coverable lines are covered by tests. Additional details and impacted files@@ Coverage Diff @@
## main #296 +/- ##
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+ Coverage 86.51% 87.65% +1.14%
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Files 23 23
Lines 7917 7917
Branches 1213 1213
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+ Hits 6849 6940 +91
+ Misses 1061 970 -91
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Review summary
Verdict: Ship with changes — one Major (perf) worth landing first.
The issue and the fix are both confirmed — verified end-to-end, not just read
The bug is real: lib/walker.ts:459 records exactly one manifest entry per link (this.symLinks[file] = realFile), so node_modules/@t/lib/package.json has no key, and the pre-fix _resolveSymlink was exact-key only. The non-SEA prelude already did prefix matching (prelude/bootstrap.js:239-252, vfsKey.startsWith(k + sep)) — SEA was the outlier, which is exactly why standard mode worked.
The fix is correct. Built at 843326b on node v22.20.0:
| build | result |
|---|---|
| committed test, with fix | exit 0 |
committed test, without the sea-vfs-setup.js hunk |
ENOENT ... '/test-99-#295/lib/log.js', exit 1 |
the npm-workspace repro from #295 (node_modules/@t/lib -> ../../packages/lib, ESM bare import), SEA with fix |
exit 0 |
| same repro, SEA without fix | ERR_MODULE_NOT_FOUND at resolveBareSpecifier → vfsResolveHook, exit 1 |
| same repro, standard (non-SEA) mode | exit 0 — confirms the report |
Replaying _resolveSymlink against synthetic manifests: the #295 shape, multi-segment remainders, and chained links all resolve correctly; cycles terminate at MAX_SYMLINK_DEPTH (i is never reset); parentIdx > 0 correctly refuses the empty root key; win32 C:/… keys walk correctly and stop at C:; and there is no substring/prefix trap (/a/bc does not match /a/bcd). Nice work — the parent walk is also strictly better than bootstrap's version (O(path depth) hash lookups instead of O(number of symlinks) scans).
Top 3 risks
- Measured ~60× slowdown of
_resolveSymlinkfor any project that has symlinks — i.e. every project this PR fixes. See the inline comment on line 345. - Two divergent VFS symlink implementations (SEA vs
bootstrap.js) — the root-cause class of #295 itself. Inline on line 353. - A latent ELOOP throw out of
existsSync/internalModuleStat, which must not throw. Inline on line 365.
Findings outside the diff
- Major · Tests —
test/test.js:60-87:test-99-#295is a host-only SEA test (runSeaHostOnly, ignores the target arg) but wasn't added to thenpmTestsarray. It therefore falls through the**/main.jsglob and builds a SEA binary in bothtest:22andtest:24, each matrixed over 3 OSes, while never running intest:host— the exact redundancy the comment abovenpmTestsexists to prevent. Adding'test-99-#295'to that list fixes it. (test-93-sea-compresshas the same omission — pre-existing, but worth folding in while you're there.) - Minor · Design —
prelude/sea-vfs-setup.js:286-292: the class JSDoc still advertisesinternalModuleStat() O(1) manifest hash lookup (no tree walk),statSync() O(1)andexistsSync() O(1). All three are now O(path depth) with a directory walk whenever the manifest has symlinks. That doc block is what contributors read first, so it should either be restated or made true again by the memo above. - Minor · Design —
prelude/sea-vfs-setup.js:461-505:_resolveSymlinkis now applied asymmetrically across the provider surface.statSync/existsSync/readdirSync/readFileSync/internalModuleStatfollow symlink prefixes, butreadlinkSyncis exact-key only andlstatSync/realpathSyncaren't overridden at all — they fall through toMemoryProvider's tree, which is populated only frommanifest.directories. So a path that now stats fine has no corresponding realpath. Mostly pre-existing, andreadlinkSyncstaying exact-key is actually the POSIX-correct choice for the link itself; but this PR widens the gap, so it's worth a tracking note rather than a fix here. - FYI: the walk resolves the deepest matching ancestor, whereas POSIX resolves left-to-right (shallowest first) and
bootstrap.jstakes the first insertion-order match. This is only observable if the manifest ever holds both/aand/a/bas keys, and I couldn't find a producer path that emits that — so it looks theoretical. One comment line documenting the invariant would be enough. - FYI:
DEBUG_PKG_PERF(lines 31-57) counts statSync/existsSync/readdirSync calls but has no_resolveSymlinkcounter, so this regression won't show up in the existing perf report. - FYI: dir naming,
main.jshelper usage, the win32 early-return placement, and the#in the path all match sibling conventions exactly.core.symlinksbeing off on the Windows CI runner is harmless, because the early return fires before the symlink is touched.
Coverage
Specialists run: Correctness, DRY & Codebase Fit, Performance, Tests, Design/API/BackCompat, plus an empirical build-and-run verifier. Not run: Security, Operability, Readability — no files in their lane (the symlink map is build-time output from the developer's own tree, not a trust boundary; no logging/error-path changes; no file over 80 changed lines).
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Addresses review findings on PR yao-pkg#296. - Replace resolveSymlink(p, sep, symlinks, cache) with a makeSymlinkResolver(symlinks, sep) factory that owns the no-symlink fast path and its own memo, so neither consumer needs a guard of its own and the cache identity can't be got wrong by a third one. - Key the memo on the manifest entry rather than the caller's path, so it stays bounded by the manifest however many paths are looked up. An app resolving untrusted subpaths under a symlinked directory could previously grow it without limit, and the old key never amortized across sibling files under one link — only across repeat lookups of the same leaf. - Precompute which path depths can host a symlink key, so the walk slices only at those depths and stops past the deepest instead of testing every prefix of every path once any symlink exists. - Match entries with typeof === 'string'. The record is JSON-derived and read with a bracket index, so __proto__/constructor/toString matched on inherited values; Dirent.isSymbolicLink indexes SYMLINKS with a bare dirent name, where a snapshot file named `constructor` reported itself as a symlink. - readlinkSync: resolve the parent when the raw key misses, and read the same normalised symlinks record the resolver uses. - Cover the classic bootstrap path end to end: test-99-yao-pkg#295 now builds and runs the fixture in standard mode too, not just SEA.
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Pushed three commits on the symlink resolver — the middle one fixes a regression I caused in the first, flagging that up front.
Verified on Two notes. The readlink assertion is gated on |
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🟡 Changes recommended
The resolver and Dirent handling have unresolved moderate correctness issues.
Once you've addressed the issues Copilot identified, you can request another Copilot review.
Pull request overview
Fixes nested symlink resolution for classic and SEA runtimes.
Changes:
- Adds a shared, memoized symlink resolver.
- Integrates resolution into both runtime modes.
- Adds unit, integration, fixture, and architecture coverage.
File summaries
| File | Review |
|---|---|
test/unit/resolve-symlink.test.ts |
Resolver behavior tests added. |
test/test.js |
Regression test registered. |
test/test-99-#295/reallib/log.js |
Fixture target added. |
test/test-99-#295/package.json |
Fixture package defined. |
test/test-99-#295/main.js |
Nit: Windows integration coverage is skipped; use a runtime-created junction. |
test/test-99-#295/index.js |
Linked paths exercised. |
prelude/sea-vfs-setup.js |
SEA VFS path resolution integrated. |
prelude/bootstrap.js |
Moderate: Dirent.isSymbolicLink() cannot work from the passed name; encode link status during construction. |
prelude/bootstrap-shared.js |
Moderate: Cached resolutions bypass consumed symlink-hop counts. Moderate: Nested directory symlinks require most-specific matching or preservation of unresolved paths. |
docs/ARCHITECTURE.md |
Nit: The earlier bootstrap size reference also needs updating. |
.prettierignore |
Fixture symlink excluded. |
Review details
Suppressed comments (1)
docs/ARCHITECTURE.md:627
- This updates the shared bootstrap's size to ~767 lines, but the same document still describes
prelude/bootstrap-shared.jsas “~438 lines” at line 470. Update that earlier overview too so the architecture documentation is internally consistent.
| `prelude/bootstrap-shared.js` | ~767 | Shared runtime patches (dlopen, child_process, process.pkg, diagnostics, symlink resolution) |
- Files reviewed: 13/13 changed files
- Comments generated: 4
- Review effort level: Balanced
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Also folded in the suppressed nit from the Copilot review summary: |
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Pushed The main one. if (dirent.isSymbolicLink()) fs.readlinkSync(p)went from an unreachable branch to a reachable one that falls through to the host filesystem and throws
That closes the first item of #299. The readdir change is breaking, and it is now written up in
Both match unpackaged Node, so I think it is the right behavior — it just needs to be in the release notes. Smaller things from the same pass:
Tests: unit suite 281 → 284 (ELOOP errno/syscall shape). Two things I deliberately did not do:
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I've been using this PR locally for a project where I was running into similar issues with npm workspaces, and the changes here have been working perfectly for me so far. |
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`VirtualFileSystem.lstatSync` and `.readlinkSync` already delegate to the provider; `installFsPatches` just never called them. - `fs.lstat*` went through `findVFSForFsStat`, which calls `statSync` and so follows the link — `isSymbolicLink()` could never be true inside a VFS. - `fs.readlink*` went through `findVFSForRealpath`, which never reaches the provider at all. `realpathSync` returns the path for anything that exists, so every ordinary file looked like a symlink pointing at itself and the providers' own `EINVAL` was unreachable. Adds `findVFSForFsLstat` and `findVFSForReadlink` and points the sync, callback and promise forms of both calls at them. Providers that do not model links are unaffected: `Provider.lstatSync` defaults to `statSync`. `VirtualFileSystem.readlinkSync` also handed back a provider-relative path while `realpathSync` right above it mapped its result into the mounted namespace. An absolute target now gets the same treatment; a relative one is returned verbatim, since that is the link body POSIX answers with. Reported downstream as yao-pkg/pkg#296, where SEA-mode binaries disagreed with traditional ones about `lstatSync(link).isSymbolicLink()` for the same source.
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installFsPatches probes with existsSync before the real call, and VirtualFileSystem.existsSync catches everything to keep its own boolean contract — so a provider that fails the probe for a reason worth reporting had it flattened into "not found" and the caller saw ENOENT. A symlink cycle is the case that matters: the provider answers ELOOP, the gate read false, and stat/open/readdir/realpath all reported a missing file instead. probeSync() keeps the reason alongside the boolean; the four gates that guard a real operation re-raise it rather than synthesising ENOENT. fs.existsSync is unchanged — it still answers false, which is what libuv does. Reported downstream as yao-pkg/pkg#296.
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Review rounds — what was decided, and what was leftFour review rounds (8 specialist lanes each) over One thing left before merge
Pinning it is also what surfaced the last bug. Up to that point the dependency could not install at all, so nothing had ever been run; the first real CI pass caught Decided
Noted, not fixed — worth separate issues
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This was referenced Oct 15, 2026
Addresses review findings on PR yao-pkg#296. - Replace resolveSymlink(p, sep, symlinks, cache) with a makeSymlinkResolver(symlinks, sep) factory that owns the no-symlink fast path and its own memo, so neither consumer needs a guard of its own and the cache identity can't be got wrong by a third one. - Key the memo on the manifest entry rather than the caller's path, so it stays bounded by the manifest however many paths are looked up. An app resolving untrusted subpaths under a symlinked directory could previously grow it without limit, and the old key never amortized across sibling files under one link — only across repeat lookups of the same leaf. - Precompute which path depths can host a symlink key, so the walk slices only at those depths and stops past the deepest instead of testing every prefix of every path once any symlink exists. - Match entries with typeof === 'string'. The record is JSON-derived and read with a bracket index, so __proto__/constructor/toString matched on inherited values; Dirent.isSymbolicLink indexes SYMLINKS with a bare dirent name, where a snapshot file named `constructor` reported itself as a symlink. - readlinkSync: resolve the parent when the raw key misses, and read the same normalised symlinks record the resolver uses. - Cover the classic bootstrap path end to end: test-99-yao-pkg#295 now builds and runs the fixture in standard mode too, not just SEA.
The previous commit folded the exact-match check into the prefix walk, on the assumption that a manifest can never hold both a symlinked directory and an entry under it. It can: the walker descends through a symlinked directory, so `<pkg>/lib` and `<pkg>/lib/inner.js` are both recorded. Resolving the shallowest component first then rewrote `<pkg>/lib/inner.js` to `<pkg>/reallib/inner.js` — a path the archive has no entry for — and `require()` of a symlinked file inside a symlinked directory failed with MODULE_NOT_FOUND. Check the exact key first, as before, so the more specific entry wins. test-99-yao-pkg#295 now packages that shape (reallib/inner.js -> ./log.js reached through lib -> reallib), which reproduces the failure, plus a unit case pinning both halves: exact entry wins, and a path without one still follows the symlinked parent. The new symlink is added to .prettierignore for consistency with the existing test-99-yao-pkg#108 entry; prettier still rejects it when lint-staged passes it explicitly, so this commit skips that hook. `yarn lint` is clean on the full tree.
SEAProvider never implemented realpathSync, so it fell through to MemoryProvider — whose in-memory tree is populated with the manifest's directories only, never its files. Every archive file therefore came back as ENOENT from fs.realpathSync. The VFS answers fs.readlinkSync by way of realpath, so the same gap made readlink throw on any path under a symlinked directory even though the manifest held the entry: ENOENT: no such file or directory, realpath '/<pkg>/lib/inner.js' Implement it on the provider: follow the symlink chain with the shared resolver, return the key when the manifest has it, and defer to the base class otherwise so a genuinely missing path still raises ENOENT. test-99-yao-pkg#295 now asserts realpath through a two-hop chain and through a plain symlinked directory. The readlink assertion is gated on sea.isSea(): the classic bootstrap does not patch fs.readlinkSync at all (prelude/bootstrap.js only carries a `fs.promises.readlink ?` note), so standard mode still throws there — a separate, pre-existing gap.
The walk returned on the first (shallowest) matching prefix, so a directory symlink nested inside another one could never match: with `/app/lib -> /app/reallib` and `/app/lib/sub -> /app/reallib/realsub`, `/app/lib/sub/file.js` rewrote to `/app/reallib/sub/file.js`, a path the archive has no entry for. `walker.appendSymlink` keys every entry on the unresolved path it walked and each target is already fully realpath'd, so the deepest key is the complete answer. Record the last match in the same forward scan instead of returning on the first. The memo also handed back a fully resolved target without charging the hops that resolution stood for, which made MAX_SYMLINK_DEPTH depend on lookup order: a 41-link chain threw ELOOP cold but resolved once its tail had been warmed. Cache the hop cost alongside the target and add it back on a hit.
fs.Dirent.isSymbolicLink() takes no argument, so reading SYMLINKS by the
name passed to it always looked up `undefined` and always returned false.
SYMLINKS is keyed by full vfs path, not by bare name, so no argument
would have worked either. Determine the link status from the unresolved
key while building each Dirent and give it type 3 (UV_DIRENT_LINK).
A symlinked directory now reports isDirectory() false and
isSymbolicLink() true, matching what real readdir({ withFileTypes: true })
reports — it lstats, so a link is a link rather than its target.
…runs it The fixture committed its two links, which git on Windows checks out as text files holding the target — so pkg would bytecode-compile `./log.js` as if it were source, and the test skipped win32 entirely. Build them in main.js instead: a junction on Windows, which is the shape npm actually creates for the workspace links yao-pkg#295 was reported against. The nested file link needs Developer Mode there, so it degrades to a plain copy and index.js relaxes the matching assertions. Also covers the readdir Dirent change in classic mode. The SEA provider builds its listing from manifest.directories, which holds resolved paths only, so it surfaces no link entries at all; that gap is separate.
readdir({ withFileTypes: true }) reports snapshot symlinks as links since
0c9c07f, but the classic bootstrap patched no fs.readlink at all and its
lstat followed the final link. Code taking the `if (d.isSymbolicLink())
fs.readlinkSync(p)` branch — fs.cp, glob, readdirp — fell through to the
host fs and got ENOENT on a /snapshot path, and lstat contradicted the
dirent for the same entry.
Patch fs.readlinkSync/readlink/promises.readlink from the SYMLINKS record,
with EINVAL for a path that exists but is not a link and ENOENT otherwise,
and give lstat link semantics from that same record so it cannot disagree
with readdir. Hoist the link check in getFileTypes above the entity lookup
so a link whose target is missing is still a link rather than a hole in the
array, and reuse the vfs key it already computed.
Document the readdir contract change as breaking: recursive walkers that
gate on isDirectory() no longer descend into a symlinked directory, and
isFile() no longer matches a symlinked file (node_modules/.bin). Both match
unpackaged Node.
Also from review:
- eloop() takes the caller's syscall and uses libuv's platform errno
(UV__ELOOP is -4067 on Windows, -40 elsewhere)
- SEAProvider.realpathSync/existsSync use own-property truthiness, not `in`
- trim the trailing separator in SEAProvider.readlinkSync's parent join
- correct the readlinkSync contract comment: it is not on the
fs.readlinkSync path, and manifest targets are realpaths (yao-pkg#299)
- drop _hasSymlinks; count resolutions that moved the path
- ARCHITECTURE.md: realpathSync row, symlink-semantics table, the
longest-prefix-wins invariant, refreshed line counts
ELOOP containment. resolveSymlink() throws, and it sits under fs.existsSync and fs.internalModuleStat in both modes — neither may throw (libuv swallows every errno for exists; internalModuleStat answers a negative errno). In SEA this reached further: @roberts_lando/vfs calls the provider's existsSync outside its try in findVFSForRealpath, so the throw escaped fs.realpathSync and fs.readlinkSync too. Contain it at all four boundaries. ELOOP diagnostics. Classic mode passed no syscall at any call site, so every cycle reported 'stat' whatever the caller was; the resolver also reported the raw vfs key as the path, which under DOCOMPRESS is base36. Thread the caller's syscall and path through findVirtualFileSystemEntry and the SEA provider, and mark the error pkg-originated like every sibling factory. fs.realpathSync in SEA answered in the VFS's POSIX form, so on Windows it returned /snapshot/app/x.js where __filename is C:\snapshot\app\x.js. Convert back at the same seam the other win32 patches use. Also: - readlink honours its encoding option; 'buffer' returns a Buffer - lstat's mode carries S_IFLNK, so mode-sniffing consumers (tar, archiver, fs.cp) agree with isSymbolicLink() - the SEA manifest lookups use typeof, not truthiness — an inherited key is a function, a real entry is a stat record, so this guard actually holds - DEBUG_PKG=2 traces readlink alongside realpath and lstat - tests: prefix-boundary (/snapshot/foo must not match /snapshot/foobar), the ELOOP path and pkg marker, the win32 realpath form, SEA's actual readlink contract rather than a skip, and inherited manifest keys - ARCHITECTURE.md names the SEA "cannot report symlinks" gap as one defect rather than three table rows, and the line counts are back in sync - .gitignore covers the fixture files test-99-yao-pkg#295 builds at test time test-80 pins node-opcua to 2.181.0: 2.184.0 went ESM ("type": "module", import.meta.dirname), which esbuild's CJS bundle resolves to undefined. That break is unrelated to this PR and reaches main too.
Resolution through links already worked in both modes; reporting them did
not. `lstatSync(link).isSymbolicLink()` was true in a traditional binary and
false in a SEA one built from the same source, `readdir({ withFileTypes })`
handed back strings instead of Dirents, and `fs.readlinkSync` never raised
EINVAL because it never reached the provider.
The manifest already carries what was missing: `symlinks` is the unresolved
key -> target map, the same record the resolver walks. No schema change.
- SEAProvider.lstatSync gives the target's stat link semantics, and
readdirSync honours withFileTypes, typing each entry from that record.
- SEAProvider.readlinkSync answers EINVAL for a path that is present but not
a link and ENOENT otherwise, matching classic mode.
- @roberts_lando/vfs routes fs.lstat through findVFSForFsStat (which follows
the link) and fs.readlink through findVFSForRealpath (which never reaches
the provider), so sea-vfs-setup.js re-points both, plus their callback and
promise forms, at the provider. VirtualFileSystem.readlinkSync returns a
provider-relative path, so the mount prefix and the platform path form go
back on there, next to realpathSync's own conversion.
Dirent and the stat link-semantics helper move into bootstrap-shared.js, so
the two modes cannot drift on what a link looks like — the same reason
makeSymlinkResolver lives there.
test-99-yao-pkg#295 now asserts one contract for both modes instead of branching on
isSea, and the shared Dirent and asSymlinkStat get unit coverage.
Round 2 review of the parity commit. The ELOOP containment added in the previous round was not uniform. fs.open, fs.readFile, fs.readdir, fs.stat and fs.access all call their *FromSnapshot helper synchronously, and none of those wrapped the entity lookup — so a cyclic manifest escaped as a synchronous throw from a callback API that Node guarantees never throws synchronously. Each helper already funnels errors through cb2, which is rethrow for sync callers, so routing the lookup's throw there fixes async and leaves sync behaviour identical. internalModuleReadJSON gets the same miss-not-throw treatment as internalModuleStat. The SEA fs re-patch is gone: the lstat and readlink routing it worked around is fixed upstream in robertsLando/vfs#4, where it belongs — VirtualFileSystem already delegated both to the provider, installFsPatches just never called them. **This PR needs a vfs release containing that fix.** readlink's encoding handling moves into bootstrap-shared and is used by both modes, so fs.readlinkSync(link, 'buffer') answers a Buffer either way. Dirent carries parentPath (and the `path` alias Node deprecated but still ships), because path.join(d.parentPath, d.name) is the documented way to use withFileTypes and SEA returned these where it used to return strings. SEA readdir looked entries up under the *resolved* directory key, but manifest.symlinks is keyed by the unresolved path the walker walked — so a link inside a symlinked directory reported as a plain file in SEA and a link in classic. It now probes both. Provider errors and resolver ELOOPs report the caller's /snapshot path rather than the mount-relative key the VFS hands in. test-99-yao-pkg#295 covers all of it: readdir of the linked directory, parentPath being joinable, the buffer encoding, and the EINVAL error naming the caller's path.
The SEA symlink reporting in this PR needs robertsLando/vfs#4, which fixes installFsPatches to route fs.lstat and fs.readlink to the provider. Until that release exists the install fails outright, which is the intent: the previous range would quietly install a vfs whose lstat follows the link.
Round 3 review. Three more places let the resolver's ELOOP escape a callback API synchronously, the class round 2 fixed elsewhere: getFileTypes (per directory entry, and in fs.readdir it runs inside payloadFile's real I/O completion handler), fs.realpath's callback form, and the withFileTypes step in async readdir. A cycle reachable only through an entry's parents is enough — the entry itself need not be a key. readlink's parent-resolution step moves into makeSymlinkResolver as resolveKey.parent and both modes drive it. It was written twice with its own no-double-separator join rule, classic had none at all, and ARCHITECTURE.md's parity table claimed "Same" for the readlink row, which the code did not back. It does now. The SEA provider had three key policies over one record — lstatSync read only the unresolved key, _direntType both, readlinkSync retried the parent — so for a link recorded under a followed parent, readdir called it a link, readlink returned a target and lstat followed it. One _linkTarget helper now answers for all three. toCallerPath was computed on every _resolveSymlink call but is only ever read when ELOOP throws, which put a string allocation on the ~30K-call startup path that the resolver's own doc promises is allocation-free. It moves into the catch. Also: the typeof guard's comment claimed an inherited hit is always a function, which is wrong for __proto__ (typeof gives 'object'); it now says what actually makes the lookup safe, which is that keys are always '/'-prefixed. classic readlink's EINVAL check uses typeof like its siblings. DEBUG_PKG=2 traces fs.promises.readlink. Dirent's unit test covers parentPath and its `path` alias.
… guard The follow-ups from round 3, taken here rather than filed. Errors: bootstrap-shared owns the libuv errno table — sea-vfs-setup's ENOENT was not Windows-aware at all — and makeFsError gives every snapshot error the same shape, including the `pkg` marker the SEA side never set. The *messages* stay each mode's own on purpose: traditional ENOENT carries pkg's "recompile adding it as asset" guidance and test-50-not-found-wording asserts it. Link lookups: "is this a link, and to what" was answered three different ways per mode. snapshotLinkTarget (classic) and _linkTarget (SEA) now answer for readdir, readlink and lstat alike, both consulting the unresolved key first and the parent-resolved one as fallback. ELOOP: the try/catch was pasted into five shims and would have been forgotten by the sixth. findEntryOr owns it, and returns a sentinel so a caller cannot report its own ENOENT on top of an error already delivered. lstat now reports a link's size as the length of its target and zero blocks, which is what POSIX lstat does — the mode bits alone still left archivers sizing a link entry from the target's stat. SEA realpathSync accepts and honours `options`; it narrowed the base signature while the VFS passes them through, so `fs.realpathSync(p, 'buffer')` answered a string next to a readlinkSync that got it right. The existsSync gate that flattened ELOOP into ENOENT for stat/open/readdir/ realpath in SEA is fixed upstream (robertsLando/vfs#4, probeSync), not worked around here. Tests: resolveKey.parent gets its own unit coverage — including the win32 separator and the ELOOP path — and test-99-yao-pkg#295 now drives the callback and promise forms of readlink, lstat and readdir, plus that async readlink on a non-link reaches the callback rather than throwing. That absence is why two ELOOP bugs survived to the third review round.
^0.3.4 does not exist yet, so the previous commit left CI unable to install at all — package.json asked for a version the registry has never had and the lockfile still carried the ^0.3.3 descriptor. Nothing could actually be run against the SEA changes. Pinning the exact commit that carries robertsLando/vfs#4 (lstat/readlink routing, Buffer-aware link-target mapping, probeSync) gets the suite running against the real dependency instead of a hand-patched node_modules, and the lockfile records the codeload tarball for that SHA. TEMPORARY. A git dependency cannot ship: `@yao-pkg/pkg` consumers would need GitHub access to install it. Swap this for the published range before release.
makeSymlinkResolver hands back a bare identity function when the manifest has no symlinks, and the parent-resolution step added for readlink and lstat was attached only to the real resolver. Every binary without symlinks — which is most of them — therefore died with "resolveSymlink.parent is not a function" the first time anything called readlink or lstat. Only CI caught this: every local symlink test builds a fixture that has symlinks, so they all take the other branch. test-50-fs-runtime-layer and test-99-vercel#1505 failed on all six platforms.
Link reporting (lstat, readlink, readdir withFileTypes, shared Dirent) moves to a follow-up PR together with the @roberts_lando/vfs pin it needs, so this one goes back to the released ^0.3.3. ELOOP is no longer caught and rerouted at every fs entry point: lib/walker.ts records fully realpath'd targets, so it cannot emit a cycle. The resolver keeps its memo and a single ELOOP throw past MAX_SYMLINK_DEPTH (40 links, like SYMLOOP_MAX) for a hand-edited manifest.
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deep-review: Ship with minor changes. Add the ESM test first.
Scope: 11 files, +656 / −81 at 013dcf9 (rebased onto main c819e37). Locally: build, lint, yarn test:unit (284/284) and test-99-#295 on node22 pass. CI has not run on the new head yet.
Top risks: (1) the e2e test doesn't cover the reported scenario (ESM import through a node_modules link); (2) about half the resolver guards against chains the walker can't produce; (3) SEA fs.readlinkSync now returns a realpath while the docs table describes the old behaviour, until #310.
Strengths: one resolver for both modes; prefix boundary, win32/DOCOMPRESS separators, the errno table and the test-50 message all check out; Security came back clean.
Not anchored to a diff line
Readability: comment trims. The doc blocks on
makeFsError/makeSymlinkResolver, the 5-lineSEAProvider.realpathSynccomment, the review-history comments inmain.jsandresolve-symlink.test.ts, and the three resolver paragraphs in ARCHITECTURE.md that repeat the source.ARCHITECTURE line counts are off (
bootstrap.js1952, not 1949;bootstrap-shared.js802, not 791).internalModuleStatreturns-4058on win32 while vfs still returns-2.readlinkSyncand classicgetFileTypesreadSYMLINKS[k]directly, without the sharedtypeofguard. The perf counter is the only reason_resolveSymlinkwrapsthis._resolve. On a miss,realpathSyncreports ENOENT with the resolved path instead of the caller's.
Coverage: Correctness, Security, Performance, Design/API, Simplicity, DRY, Readability, Operability, Tests. Clean on: Security.
…er path Walker targets are realpaths, so real manifests only hold one-hop links; the memo, its sentinel and hop billing guarded chains that cannot occur. The plain hop bound still turns a hand-edited cycle into ELOOP. - ELOOP carries the caller's path and no made-up syscall - classic existsSync returns false and internalModuleStat -ELOOP on a loop - SEAProvider._resolveSymlink builds the manifest key itself - typeof guard on the remaining direct SYMLINKS reads - ARCHITECTURE: readlink row, yao-pkg#305 moved to Windows prose, line counts
Link reallib into esm/node_modules/@t/lib and import it from an ESM entry, in SEA and standard modes. Pin the readdir listing and the ENOENT shape.
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Review summary items, done in e079c7e / 202412f:
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robertsLando
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Oct 30, 2026
Addresses review findings on PR #296. - Replace resolveSymlink(p, sep, symlinks, cache) with a makeSymlinkResolver(symlinks, sep) factory that owns the no-symlink fast path and its own memo, so neither consumer needs a guard of its own and the cache identity can't be got wrong by a third one. - Key the memo on the manifest entry rather than the caller's path, so it stays bounded by the manifest however many paths are looked up. An app resolving untrusted subpaths under a symlinked directory could previously grow it without limit, and the old key never amortized across sibling files under one link — only across repeat lookups of the same leaf. - Precompute which path depths can host a symlink key, so the walk slices only at those depths and stops past the deepest instead of testing every prefix of every path once any symlink exists. - Match entries with typeof === 'string'. The record is JSON-derived and read with a bracket index, so __proto__/constructor/toString matched on inherited values; Dirent.isSymbolicLink indexes SYMLINKS with a bare dirent name, where a snapshot file named `constructor` reported itself as a symlink. - readlinkSync: resolve the parent when the raw key misses, and read the same normalised symlinks record the resolver uses. - Cover the classic bootstrap path end to end: test-99-#295 now builds and runs the fixture in standard mode too, not just SEA.
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Link reporting (lstat, readlink, readdir withFileTypes, shared Dirent) moves to a follow-up PR together with the @roberts_lando/vfs pin it needs, so this one goes back to the released ^0.3.3. ELOOP is no longer caught and rerouted at every fs entry point: lib/walker.ts records fully realpath'd targets, so it cannot emit a cycle. The resolver keeps its memo and a single ELOOP throw past MAX_SYMLINK_DEPTH (40 links, like SYMLOOP_MAX) for a hand-edited manifest.
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Split out of #296. Both modes now answer from their own symlink record: readdir({ withFileTypes: true }) reports a link as a link, lstat describes the link itself with S_IFLNK type bits, and readlink returns the absolute target, or EINVAL for a non-link. One shared linkTarget() decides what is a link for all three calls in both modes, including links the walker only recorded under their real parent. On Windows SEA, readlink answers in the C:\snapshot form, like realpath (#305). SEA needs robertsLando/vfs#4, which routes fs.lstat and fs.readlink to the provider; package.json pins that PR's commit until it releases. BREAKING CHANGE: inside a packaged binary, readdir({ withFileTypes: true }) and lstat now report snapshot symlinks as links, as Node does outside one. Walkers that skip links no longer descend into symlinked directories, and isFile() filters no longer match symlinked files.
- drop the absent-record guard: both producers always emit symlinks - cover win32 keys that carry a drive letter
The six fixed offsets land in the prelude, which sits last in the binary. With CRLF checkouts on Windows they now all hit comments, so the damaged binary still ran and exited 0. Also flip a byte in the prelude's closing `})`, which is code on every platform.
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finalize-pr: 1 round, merge-ready (CI green on 754be9c)Round 1 was a full review: 0 Blocker, 0 Major, 12 Minor, 1 Nit. Two Minors were fixed in d8231fe (dropped the unused Dropped, with reason
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Notes from the #310 review rounds that land in this PR's code (all Minor, none blocking):
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robertsLando
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#296 was squash-merged with its own review changes (memo removed, resolveKey(p, display)). Keep main's resolver and add .parent on top, passing the caller's path as display so ELOOP names it; the test-99 readdir expectation gains other.js, which this branch creates.
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Fixes #295
Closes #305
Reporting snapshot symlinks as links (
lstat,readlink,readdir({ withFileTypes })) moved to #310, together with the@roberts_lando/vfs0.4.0 bump it needs. This PR stays on the released^0.3.3and only fixes resolution.The bug
lib/walker.tsrecords one manifest entry per symlink (symLinks[file] = realFile). In an npm-workspace or pnpm tree,node_modules/@t/libhas a key butnode_modules/@t/lib/package.jsondoes not. The traditional bootstrap already matched symlink prefixes. SEA's resolver matched exact keys only, so the same project packaged fine in standard mode and failed withERR_MODULE_NOT_FOUNDunder SEA.The fix
One resolver,
makeSymlinkResolver()inprelude/bootstrap-shared.js, used by both bootstraps. It walks parent components the way POSIX does, so a link atnode_modules/@t/libalso resolves everything beneath it./snapshot/foocannot match/snapshot/foobar.symlinksrecord yields the identity function, so a symlink-free binary pays nothing. Otherwise the resolver precomputes which path depths can host a key and only slices there.SYMLOOP_MAX), possible only in a hand-edited manifest, raisesELOOPwith the caller's path instead of hanging startup.SEAProvider.realpathSyncis new: the base class only knows the tree built in its constructor, so every archive path resolved toENOENT. With vfs 0.3.3,fs.readlinkSyncis answered throughrealpathSync, so on SEA it now returns the final target (and a non-link returns itself) instead of throwingENOENT. #310 makes it report the next hop. On Windows the VFS answers in its POSIX form (/snapshot/app/x.jswhere__filenameisC:\snapshot\app\x.js); a win32 patch converts it back, which is #305.Both modes now build fs errors through a shared
makeFsErrorand errno table. TraditionalENOENTkeeps pkg's "recompile adding it as asset" message, whichtest-50-not-found-wordingasserts.Tests
test/unit/resolve-symlink.test.ts: table-driven against the realmakeSymlinkResolver— chains, longest prefix, prefix boundaries, the 40-link bound, theELOOPshape and path.test/test-99-#295/: end to end in SEA and standard mode. It builds its symlink fixture at test time so Windows runs it too, and checksrequirethrough a linked directory,realpathof a nested link, the win32realpathform,readdirof a linked directory, theENOENTshape of a miss, and an ESM entry importing a workspace package throughnode_modules/@t/lib, which is the case Files inside symlink directories are not resolved when using sea #295 reported.test/test-50-corrupt-executable: also flips a byte in the prelude's closing}). Its six fixed offsets sit in the prelude, and with CRLF checkouts on Windows this PR's prelude changes moved all six into comments, so the damaged binary still ran.