- Include `optionalDependencies` in the declared tier's candidate union. A
peer range constrains the consumer's host; an optional range is a direct
declaration npm attempts to install, so omitting it left an optional-only
package free to skew unseen. `peerDependencies` stays excluded, with the
reason stated.
- Make the end-to-end fixture's client copy UNDECLARED — only the root
manifest names `solo`, while `clients/web` merely holds a top-level copy.
That is #2226's defining shape, and it is what makes the candidate set a
union across installs rather than a per-install intersection; the old
fixture would have passed a per-install implementation. Adds the mirror
case (declared only by a client, held by the root) so the union is pinned
in both directions.
- Update the two docs that still described the single-tier guard:
`.claude/skills/local-dev/SKILL.md` said "nothing gates either of those,
and `verify:dep-lockstep` is not it" and cited the live `@types/node`
drift in the present tense; `docs/quality-gate.md` described only the
program tier. Both now state what each tier covers and the two limits
that remain.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01J86a6vMcA9csPtdsg7ZcCZ
Signed-off-by: cliffhall <cliff@futurescale.com>
`clients/cli` resolved `@types/node` 24.13.1 against the root's 24.13.3.
Neither client declares it — #2196 consolidated it to the root — so the cli
copy arrived transitively via `@types/express` and was constrained by no
range of ours. `verify:dep-lockstep` reported OK and was right to: it
compares only packages that reach one `tsc` **program** from two installs,
and no one program sees both copies.
Fixes the instance and the class, which the issue notes are not exclusive.
**The class.** The guard grows a second tier alongside the program-derived
one, asking the weaker but broader question `AGENTS.md`'s "one version per
install-crossing dependency" rule actually states: does a package this repo
declares anywhere resolve to two versions across our installs at all? The
candidate set is every name in any install's `dependencies`/`devDependencies`
that more than one install holds a **top-level** copy of — 17 packages today.
Nested copies are excluded: one exists because some dependency asked for a
different version, so it is that dependency's range, not ours.
Neither tier subsumes the other. The program tier sees a copy no manifest
names (the `@modelcontextprotocol/sdk` case, arriving through another
package's `.d.ts`). The declared tier sees a transitive copy no program
loads (this issue), two *clients* disagreeing with no root copy involved
(`@types/react`, web against tui), and the peer shadows `AGENTS.md` calls out
as ungated — `eslint`, `typescript`, `vitest`.
Deny-by-default, with its own empty `TOLERATED_DECLARED_SKEW` and the same
within-a-major rule, now stated once in a shared `toleratesSkew` so the two
tiers cannot drift.
**The instance, and three others the new tier surfaced.** All four were
patch-level:
- `@types/node` — cli 24.13.1 vs root 24.13.3. Transitive, so it takes an
`overrides` entry in `clients/cli` (the repo's sanctioned lever for a
transitive pin), at the root's own `^24.12.4` rather than a frozen number.
- `@types/react` — web 19.2.18 vs tui 19.2.17.
- `react` — web 19.2.8 vs root/tui 19.2.7.
- `@vitejs/plugin-react` — web 6.0.5 vs root 6.0.2.
The last three are `npm update` in the stale install: it moves the lockfile
within the declared range without widening a range, which matters for the
root `react ^19.0.0` that `ink`'s externalized-bundle exemption depends on.
No declaration or range changed.
Tests: 4 end-to-end cases (the fixture gains manifest deps and a client-side
`solo` install, so the skew is real and no program holds both copies) and 13
helper cases.
Closes#2226
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01J86a6vMcA9csPtdsg7ZcCZ
Signed-off-by: cliffhall <cliff@futurescale.com>
Upstream #1965 moved the tsc --listFilesOnly machinery into
scripts/lib/tsc-program.mjs (shared with the new verify:dep-lockstep),
still spawning `npx` — which is ENOENT on Windows. Resolve the conflict
by taking upstream's factoring and porting the #1939 fix into the lib:
rawProjectListing and verify-typecheck-coverage's --showConfig pass now
spawn process.execPath with the cached, hard-failing tscEntry resolver
(exported from tsc-program.mjs). Fixture copies in both main tests pick
up the new lib import graph. verify:dep-lockstep now runs on Windows
too.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Two findings from the Copilot review of #1965, both real.
1. The candidates were flattened to package names before the version
comparison, so a third install holding a different copy failed the guard
even when no program loads that copy beside another — and the diagnostic
named an install that never took part. `crossInstallPackages` now returns
the co-occurrences themselves (name → program → install → entry paths) and
`findSkew` compares per program, across only the installs that met there.
2. Folding a nested copy onto its outermost install lost the path that
identifies which copy was loaded, and the version was then read from the
install's top-level entry — absent or differently versioned, either way
letting a real pair pass. `classifyModulePath` now also returns the
`entryPath` npm keys the lockfile by, `topLevelLockVersions` becomes
`lockVersionsByPath`, and each holder is priced from the entry the program
resolved. A resolved copy with no lockfile entry is now a hard failure
rather than a silently dropped holder.
The failure output prints `in <program>` with each holder's install path
beside its version, so a nested copy is distinguishable from a top-level one.
Signed-off-by: cliffhall <cliff@futurescale.com>
`verify:dep-lockstep` derived its candidate set from the packages the shared
first-party sources named *directly*, so a package whose declarations reach a
program only through another package's `.d.ts` was invisible to it — it could
skew across installs and recreate the two-copy blow-up #1896 was about while
the guard stayed green. `@modelcontextprotocol/sdk` was the live example: never
written in first-party code, yet 16 of its `.d.ts` files land in clients/web's
test program.
Replace the derivation with the measured one: list every client tsconfig
project with `tsc --listFilesOnly`, map each resolved `node_modules` file to
its owning install and package, and keep the packages that reach ONE program
from TWO installs. That is exactly the set that can put two structurally
distinct copies of a type in front of one checker. The rest of the guard is
unchanged — top-level lockfile comparison, deny-by-default, `TOLERATED_SKEW` as
a name allowlist scoped to within-a-major.
The listing machinery moves to `scripts/lib/tsc-program.mjs`, shared with
`verify:typecheck-coverage`, so the two guards can't disagree about what a
program contains. It is deliberately not cached to disk between the two
processes: a stale fingerprint would make a guard measure a program that no
longer exists and pass on a real miss. The second pass costs ~14s.
`TOLERATED_SKEW` is now empty. `jose` and `@modelcontextprotocol/ext-apps` are
root-only since #1970 and cannot skew; `react` (whose types are `@types/react`,
resolved from one install) and `hono` never reach one program from two
installs. Each would be a rationale for a skew that cannot occur.
Closes#1965
Signed-off-by: cliffhall <cliff@futurescale.com>
From Copilot's fifteenth pass of #1962. `installDirs` filtered on the presence
of a lockfile, so a missing one silently removed that install from the
comparison rather than failing. For the root — the install every shared source
resolves from — that meant the guard could report success from client locks
alone, which is the deny-by-default contract inverted.
Enrolment is now by `package.json` (an install we are meant to compare), with
the root always enrolled, and a missing lockfile is a named, loud failure. A
`clients/` directory with no `package.json` is not an install and is skipped,
so a stray scratch dir isn't asked for a lockfile it should never have.
Three regression cases: a missing client lockfile in a fixture that IS skewed
(so failing open would show as a pass), a missing ROOT lockfile, and a stray
`clients/` dir that must not be enrolled.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01HDdo1rNRVQnVRRdsqSrvG3
From Copilot's eleventh pass of #1962, and the most consequential kind of bug
for a gate: it failed *open*.
`topLevelLockVersions` returns an empty map for anything without a v2+
`packages` table — a lockfileVersion 1 file, or a malformed one. `main()` fed
that straight into the comparison, so such an install contributed no holders
at all, and a genuine skew among the remaining installs was reported as
aligned. The guard would have said OK to exactly what it exists to catch.
`hasReadableLockShape` now gates every discovered lockfile before any
comparison, requiring a `packages` object carrying the `""` root entry npm
always writes — "has a packages key" is not enough. An unreadable one is named
and exits 1, telling you to regenerate it. A JSON parse failure likewise
reports the file rather than dying on a bare SyntaxError with no path in it.
The empty-map behavior of the pure helper is kept and its test now says why it
is safe: the shape check rejects those inputs before they can reach
`findSkew`.
Three regression cases: a v1 lockfile in a fixture that IS skewed (so failing
open would show as a pass), a `packages` table with no root entry, and the
unit table for the predicate. Fixtures now write the `""` root entry, matching
real npm output.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01HDdo1rNRVQnVRRdsqSrvG3
From Copilot's tenth pass of #1962. The suite covered only pure helpers, so a
regression in source enumeration, install discovery, lockfile loading, the
sibling-guard vouch, or the nonzero exit on real skew would have left it
green — and the negative cases had only ever been run by hand, once per review
round.
Five end-to-end cases build a throwaway repo and run the guard as a
subprocess: aligned installs exit 0; a skewed one exits 1 naming the package
and every holder while leaving the agreeing package unreported; a package
imported only by `test-servers/src` still fails (so dropping the second shared
tree can't pass); a shared source matching no tracked file fails; and a
`validate` chain that stopped running `verify:format-coverage` fails the vouch
even when the versions are fine.
The fixture must be realpath'd. On macOS `tmpdir()` is `/var/…`, a symlink to
`/private/var/…`, and the guard runs `main()` only when `import.meta.url` (the
resolved path) matches `process.argv[1]` — so launching it via the unresolved
path loads the module and does nothing, exiting 0 silently. That is how all
five first "passed" as no-ops, and the comment records it.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01HDdo1rNRVQnVRRdsqSrvG3
