test: give the 10k-iteration sort-key property test its own timeout #318

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fable-5 merged 1 commits from fix/sort-key-test-timeout into main 2026-08-02 14:30:05 +02:00

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@ -26,48 +26,56 @@ describe('sort-key helpers (issue #45)', () => {
* pattern repeatedly drop the last page between the first two must never
* collide and never overflow the key length, because the caller rebalances
* when {@link nextKeyOrRebalance} returns null.
*
* Under parallel CI load the 10.000 iterations have repeatedly exceeded the
* default 5 s per-test timeout (runs 685, 699 same code passed on rerun),
* so this test carries its own budget.
*/
it('10.000 adversarial reorders never collide or overflow (rebalance verified)', () => {
// Start with five pages in a fixed order.
let order = evenlySpacedKeys(5).map((key, i) => ({ id: `p${i}`, key }));
let rebalances = 0;
it(
'10.000 adversarial reorders never collide or overflow (rebalance verified)',
{ timeout: 30_000 },
() => {
// Start with five pages in a fixed order.
let order = evenlySpacedKeys(5).map((key, i) => ({ id: `p${i}`, key }));
let rebalances = 0;
const rebalance = (): void => {
const keys = evenlySpacedKeys(order.length);
order = order.map((page, i) => ({ ...page, key: keys[i]! }));
rebalances += 1;
};
const rebalance = (): void => {
const keys = evenlySpacedKeys(order.length);
order = order.map((page, i) => ({ ...page, key: keys[i]! }));
rebalances += 1;
};
for (let i = 0; i < 10_000; i += 1) {
// Move the last page to sit between the first and second — the tightest
// possible gap, which is what grows key length fastest.
const moved = order[order.length - 1]!;
const rest = order.slice(0, -1);
const afterKey = rest[0]!.key;
const beforeKey = rest[1]!.key;
for (let i = 0; i < 10_000; i += 1) {
// Move the last page to sit between the first and second — the tightest
// possible gap, which is what grows key length fastest.
const moved = order[order.length - 1]!;
const rest = order.slice(0, -1);
const afterKey = rest[0]!.key;
const beforeKey = rest[1]!.key;
const key = nextKeyOrRebalance(afterKey, beforeKey);
if (key === null) {
// Rebalance keeps the CURRENT order, then retry the move once.
rebalance();
const k2 = nextKeyOrRebalance(order[0]!.key, order[1]!.key);
expect(k2).not.toBeNull();
order = [order[0]!, { ...moved, key: k2! }, ...order.slice(1)];
} else {
order = [rest[0]!, { ...moved, key }, ...rest.slice(1)];
const key = nextKeyOrRebalance(afterKey, beforeKey);
if (key === null) {
// Rebalance keeps the CURRENT order, then retry the move once.
rebalance();
const k2 = nextKeyOrRebalance(order[0]!.key, order[1]!.key);
expect(k2).not.toBeNull();
order = [order[0]!, { ...moved, key: k2! }, ...order.slice(1)];
} else {
order = [rest[0]!, { ...moved, key }, ...rest.slice(1)];
}
// Invariants after every move: keys unique, bounded, and consistent with
// the intended array order.
const keys = order.map((p) => p.key);
expect(new Set(keys).size).toBe(keys.length);
expect(Math.max(...keys.map((k) => k.length))).toBeLessThanOrEqual(MAX_SORT_KEY_LENGTH);
for (let j = 1; j < keys.length; j += 1) {
expect(keys[j - 1]! < keys[j]!).toBe(true);
}
}
// Invariants after every move: keys unique, bounded, and consistent with
// the intended array order.
const keys = order.map((p) => p.key);
expect(new Set(keys).size).toBe(keys.length);
expect(Math.max(...keys.map((k) => k.length))).toBeLessThanOrEqual(MAX_SORT_KEY_LENGTH);
for (let j = 1; j < keys.length; j += 1) {
expect(keys[j - 1]! < keys[j]!).toBe(true);
}
}
// The adversarial pattern must have forced at least one rebalance.
expect(rebalances).toBeGreaterThan(0);
});
// The adversarial pattern must have forced at least one rebalance.
expect(rebalances).toBeGreaterThan(0);
},
);
});