fix: added falback to maxExitEpoch

Author: Tarens2

src/waiting-time/waiting-time.service.ts

@@ -90,14 +90,14 @@ export class WaitingTimeService {
     const additionalStETH = parseEther(amount || '0');
     const queueStETH = unfinalized.add(additionalStETH);
 
-    const latestEpoch = this.validators.getMaxExitEpoch();
+    const maxExitEpoch = this.getMaxExitEpoch();
 
     const { frame, type } = await this.calculateWithdrawalFrame({
       unfinalized: queueStETH,
       vaultsBalance,
       buffer,
       requestTimestamp: Date.now(),
-      latestEpoch,
+      latestEpoch: maxExitEpoch.toString(),
     });
     const ms = this.genesisTimeService.timeToWithdrawalFrame(frame, Date.now());
     const finalizationIn = validateTimeResponseWithFallback(ms) + GAP_AFTER_REPORT;
@@ -132,7 +132,7 @@ export class WaitingTimeService {
     const nextCalculationAt = this.queueInfo.getNextUpdate().toISOString();
     const request = requests.find((item) => item.id.eq(BigNumber.from(requestId)));
 
-    const maxExitEpoch = this.validators.getMaxExitEpoch();
+    const maxExitEpoch = this.getMaxExitEpoch();
     const currentEpoch = this.genesisTimeService.getCurrentEpoch();
 
     const queueStETH = calculateUnfinalizedEthToRequestId(requests, request);
@@ -325,7 +325,7 @@ export class WaitingTimeService {
   private async checkInPastCase(args: CheckInPastCaseArgs) {
     const { request, vaultsBalance, buffer, type, frame } = args;
 
-    const maxExitEpoch = this.validators.getMaxExitEpoch();
+    const maxExitEpoch = this.getMaxExitEpoch();
     const requests = this.queueInfo.getRequests();
     const requestTimestamp = request.timestamp.toNumber() * 1000;
     const queueStETH = calculateUnfinalizedEthToRequestId(requests, request);
@@ -477,14 +477,14 @@ export class WaitingTimeService {
 
   public calculateRequestTimeSimple(unfinalizedETH: BigNumber): number {
     const currentEpoch = this.genesisTimeService.getCurrentEpoch();
-    const latestEpoch = this.validators.getMaxExitEpoch();
+    const maxExitEpoch = this.getMaxExitEpoch();
     const totalValidators = this.validators.getActiveValidatorsCount();
 
     const churnLimit = Math.max(MIN_PER_EPOCH_CHURN_LIMIT, totalValidators / CHURN_LIMIT_QUOTIENT);
 
     const lidoQueueInEpoch = unfinalizedETH.div(MIN_ACTIVATION_BALANCE.mul(Math.floor(churnLimit)));
     const sweepingMean = this.validators.getSweepMeanEpochs();
-    const potentialExitEpoch = BigNumber.from(latestEpoch).add(lidoQueueInEpoch).add(sweepingMean);
+    const potentialExitEpoch = BigNumber.from(maxExitEpoch).add(lidoQueueInEpoch).add(sweepingMean);
 
     const waitingTime = potentialExitEpoch
       .sub(currentEpoch)
@@ -494,4 +494,12 @@ export class WaitingTimeService {
 
     return Math.round(waitingTime.toNumber());
   }
+
+  // returns max exit epoch of validators with fallback to current epoch if max exit epoch already passed
+  public getMaxExitEpoch() {
+    const maxExitEpoch = this.validators.getMaxExitEpoch();
+    const currentEpoch = this.genesisTimeService.getCurrentEpoch();
+
+    return Math.max(+maxExitEpoch, currentEpoch + MAX_SEED_LOOKAHEAD + 1);
+  }
 }