test(devx): sweep the shrink-only ratchet self-tests for baseline-presence pins — 33 derived, 1 repaired

scripts/check-driver-memory-census.mjs

@@ -124,6 +124,16 @@ const DEP_FIELDS = ['dependencies', 'devDependencies', 'peerDependencies', 'opti
 /** Binding kinds a ledger entry may claim. `string-literal` is context, never gated. */
 const BINDING_KINDS = ['import', 'export-from', 'dynamic-import', 'import-type', 'require', 'mock'];
 
+/**
+ * Ceiling on `ruledConsumers` — the two arms #5704 Q2 and #6664 A ruled permanent.
+ *
+ * A CEILING, deliberately, and not the set's exact size: #5499 froze the driver and
+ * the programme above this gate exists to shrink the ruled set, so a PR that migrates
+ * an arm away lowers this number in the same edit. Raising it is a new maintainer
+ * ruling — the same authority `RULING_ISSUES` names in the self-test.
+ */
+const RULED_CEILING = 2;
+
 /**
  * The disposition vocabulary. Closed on purpose: a free-text axis would let the
  * next arrival be waved through with a word nobody has to defend.
@@ -664,8 +674,46 @@ function selfTest() {
  expect(`discovery reaches the ruled consumer ${e.file}`,
  realScan.bindings.some((b) => b.file === e.file && b.kind === e.kind));
  }
- expect('the ledger rules exactly the consumers #5704/#6664 named',
- (realLedger.ruledConsumers ?? []).length === 2);
+ // The claim here is about the RULING AUTHORITY, not about the ledger's current
+ // length.
+ //
+ // ⚠️ This was spelled `ruledConsumers.length === 2` — "the ledger rules exactly
+ // the consumers #5704/#6664 named". That reads identically on the day it is
+ // written and means something else: it holds only while both arms are STILL
+ // ledgered, so the gate's own LIVE invariant ("a migrated consumer must lose its
+ // entry in the same PR") cannot be obeyed without turning this self-test red —
+ // and red with a message that reads "the ledger lost an entry it must have" when
+ // the entry was correctly deleted. A pin on the debt rather than on the gate:
+ // the retirement programme #5499/#5704 exists to shrink this set, and an
+ // equality on its size makes it un-burnable by construction.
+ //
+ // What the pin was actually protecting is the OTHER direction: no third consumer
+ // may be waved into `ruled-permanent` — the strongest disposition this census
+ // has — under a marker of its own invention. `validateLedgerShape` already
+ // requires SOME rulingMarker; it does not require the ruling to be one this
+ // programme actually issued. So that is the claim, and it survives the set
+ // shrinking to empty.
+ const RULING_ISSUES = ['#5704', '#6664'];
+ const admittedByARuling = (e) => (e.rulingMarkers ?? []).some((m) => RULING_ISSUES.includes(m));
+ const ruled = realLedger.ruledConsumers ?? [];
+
+ // Carried on a WITNESS PAIR rather than on the live rows alone: `[].every(...)`
+ // is a pass that proves nothing, so the synthetic row keeps the positive half
+ // exercised once the ledger reaches zero, and the negative witness is what gives
+ // the case teeth at that point. (The `ESCAPABLE_LITERAL_LEDGER` cases in
+ // scripts/pm/dispatch-gates.mjs are the worked precedent for the idiom.)
+ const WITNESS_RULED = { file: 'w/itness.test.ts', kind: 'import', axis: 'ruled-permanent', rulingMarkers: ['#6664'] };
+ const WITNESS_UNRULED = { file: 'w/itness.test.ts', kind: 'import', axis: 'ruled-permanent', rulingMarkers: ['#0'] };
+ expect('every ruled consumer is admitted by one of this programme\'s two rulings',
+ [...ruled, WITNESS_RULED].every(admittedByARuling));
+ expect('…and that rule can FAIL: a marker neither ruling issued does not admit a consumer',
+ !admittedByARuling(WITNESS_UNRULED));
+
+ // The anti-GROWTH half, as a ceiling rather than an equality. It may be lowered
+ // by any PR that migrates an arm away; raising it is a new maintainer ruling,
+ // which is the same authority `RULING_ISSUES` names.
+ expect(`the ruled set never grows past what those rulings named (${RULED_CEILING} arm(s); it may shrink to empty)`,
+ ruled.length <= RULED_CEILING);
  }
 
  if (failures.length) {
@@ -679,8 +727,9 @@ function selfTest() {
  + 'entry, a log line, a comment), reads dependency fields but not a manifest\'s own `name`, reports an '
  + 'unledgered arrival AND a stale ledger entry AND a changed binding kind, refuses an unknown axis or an '
  + 'empty `why`, fails when a ruling marker is deleted, fails when a ruled file stops stating the census '
- + 'count, shows that growing the ruled set invalidates every sentence still carrying the old count, and '
- + 'proves discovery reaches both ruled consumers in the real tree.',
+ + 'count, shows that growing the ruled set invalidates every sentence still carrying the old count, '
+ + 'proves discovery reaches every ruled consumer in the real tree, and holds the ruled set to the '
+ + 'rulings that admitted it — a claim that survives the set shrinking to empty.',
  );
 }