refactor: computeRoundTiming should not allow duration === frequency

Agoric · Mar 5, 2023 · 42dd965 · 42dd965
1 parent 8d641af
commit 42dd965
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Showing 3 changed files with 52 additions and 17 deletions.
diff --git a/packages/inter-protocol/src/auction/scheduler.js b/packages/inter-protocol/src/auction/scheduler.js
@@ -57,17 +57,23 @@ export const computeRoundTiming = (params, baseTime) => {
     Fail`startFrequency must exceed lock period, ${freq}, ${lockPeriod}`;
 
   startingRate > lowestRate ||
-    Fail`startingRate ${startingRate} must be more than ${lowestRate}`;
+    Fail`startingRate ${startingRate} must be more than lowest: ${lowestRate}`;
   const rateChange = subtract(startingRate, lowestRate);
   const requestedSteps = floorDivide(rateChange, discountStep);
   requestedSteps > 0n ||
     Fail`discountStep ${discountStep} too large for requested rates`;
   TimeMath.compareRel(freq, clockStep) >= 0 ||
-    Fail`clockStep ${clockStep} must be shorter than startFrequency ${freq} to allow >1 steps `;
+    Fail`clockStep ${TimeMath.relValue(
+      clockStep,
+    )} must be shorter than startFrequency ${TimeMath.relValue(
+      freq,
+    )} to allow at least one step down`;
 
   const requestedDuration = TimeMath.multiplyRelNat(clockStep, requestedSteps);
   const targetDuration =
-    TimeMath.compareRel(requestedDuration, freq) < 0 ? requestedDuration : freq;
+    TimeMath.compareRel(requestedDuration, freq) < 0
+      ? requestedDuration
+      : TimeMath.subtractRelRel(freq, TimeMath.toRel(1n));
   const steps = TimeMath.divideRelRel(targetDuration, clockStep);
   const duration = TimeMath.multiplyRelNat(clockStep, steps);
 

diff --git a/packages/inter-protocol/test/auction/test-computeRoundTiming.js b/packages/inter-protocol/test/auction/test-computeRoundTiming.js
@@ -175,9 +175,9 @@ test(
   100,
   {
     startTime: 3600 + 300,
-    endTime: 3600 + 6 * 10 * 60 + 300,
-    steps: 6n,
-    endRate: 10_500n - 6n * 10n,
+    endTime: 3600 + 5 * 10 * 60 + 300,
+    steps: 5n,
+    endRate: 10_500n - 5n * 10n,
     startDelay: 300,
     clockStep: 600,
   },
@@ -192,9 +192,9 @@ test(
   100,
   {
     startTime: 3600 + 300,
-    endTime: 3600 + 6 * 10 * 60 + 300,
-    steps: 6n,
-    endRate: 10_500n - 6n * 350n,
+    endTime: 3600 + 5 * 10 * 60 + 300,
+    steps: 5n,
+    endRate: 10_500n - 5n * 350n,
     startDelay: 300,
     clockStep: 600,
   },

diff --git a/packages/inter-protocol/test/auction/test-scheduler.js b/packages/inter-protocol/test/auction/test-scheduler.js
@@ -215,7 +215,7 @@ test('lowest >= starting', async t => {
   await t.throwsAsync(
     () =>
       makeScheduler(fakeAuctioneer, timer, paramManager, timer.getTimerBrand()),
-    { message: '-5 is negative' },
+    { message: /startingRate "\[105n]" must be more than lowest: "\[110n]"/ },
   );
 });
 
@@ -257,7 +257,10 @@ test('zero time for auction', async t => {
   await t.throwsAsync(
     () =>
       makeScheduler(fakeAuctioneer, timer, paramManager, timer.getTimerBrand()),
-    { message: /Frequency .* must exceed duration/ },
+    {
+      message:
+        /clockStep "\[3n]" must be shorter than startFrequency "\[2n]" to allow at least one step down/,
+    },
   );
 });
 
@@ -475,6 +478,8 @@ test('duration = freq', async t => {
   const publisherKit = makePublisherFromFakes();
 
   let defaultParams = makeDefaultParams(fakeInvitationPayment, timerBrand);
+  // start hourly, request 6 steps down every 10 minutes, so duration would be
+  // 1 hour. Instead cut the auction short.
   defaultParams = {
     ...defaultParams,
     priceLockPeriod: 20n,
@@ -501,11 +506,35 @@ test('duration = freq', async t => {
     params2,
   );
 
-  await t.throwsAsync(
-    () =>
-      makeScheduler(fakeAuctioneer, timer, paramManager, timer.getTimerBrand()),
-    {
-      message: /Frequency .* must exceed duration .*/,
-    },
+  const scheduler = await makeScheduler(
+    fakeAuctioneer,
+    timer,
+    paramManager,
+    timer.getTimerBrand(),
   );
+  let schedule = scheduler.getSchedule();
+  t.deepEqual(schedule.liveAuctionSchedule, undefined);
+  const firstSchedule = {
+    startTime: TimeMath.toAbs(365n, timerBrand),
+    endTime: TimeMath.toAbs(665n, timerBrand),
+    steps: 5n,
+    endRate: 50n,
+    startDelay: TimeMath.toRel(5n, timerBrand),
+    clockStep: TimeMath.toRel(60n, timerBrand),
+  };
+  t.deepEqual(schedule.nextAuctionSchedule, firstSchedule);
+
+  await timer.advanceTo(725n);
+  schedule = scheduler.getSchedule();
+
+  // start the second auction on time
+  const secondSchedule = {
+    startTime: TimeMath.toAbs(725n, timerBrand),
+    endTime: TimeMath.toAbs(1025n, timerBrand),
+    steps: 5n,
+    endRate: 50n,
+    startDelay: TimeMath.toRel(5n, timerBrand),
+    clockStep: TimeMath.toRel(60n, timerBrand),
+  };
+  t.deepEqual(schedule.nextAuctionSchedule, secondSchedule);
 });