feat(pulse-scheduler): add permanent subscriptions, allow permissionless funding, clean up tests (#2593)

* feat: add permanent subscriptions, clean up tests

* fix: disallow config and whitelist updates for permanent subs

* fix: disallow updating isActive for permanent subscriptions

* doc: clarify comment

Author: tejasbadadare

target_chains/ethereum/contracts/contracts/pulse/scheduler/Scheduler.sol

@@ -98,6 +98,11 @@ abstract contract Scheduler is IScheduler, SchedulerState {
         bool wasActive = currentParams.isActive;
         bool willBeActive = newParams.isActive;
 
+        // Check for permanent subscription restrictions
+        if (currentParams.isPermanent) {
+            _validatePermanentSubscriptionUpdate(currentParams, newParams);
+        }
+
         // If subscription is inactive and will remain inactive, no need to validate parameters
         if (!wasActive && !willBeActive) {
             // Update subscription parameters
@@ -385,6 +390,103 @@ abstract contract Scheduler is IScheduler, SchedulerState {
         revert UpdateConditionsNotMet();
     }
 
+    /**
+     * @notice Internal helper to validate modifications to a permanent subscription.
+     * @param currentParams The current subscription parameters (storage).
+     * @param newParams The proposed new subscription parameters (memory).
+     */
+    function _validatePermanentSubscriptionUpdate(
+        SubscriptionParams storage currentParams,
+        SubscriptionParams memory newParams
+    ) internal view {
+        // Cannot disable isPermanent flag once set
+        if (!newParams.isPermanent) {
+            revert IllegalPermanentSubscriptionModification();
+        }
+
+        // Cannot deactivate a permanent subscription
+        if (!newParams.isActive) {
+            revert IllegalPermanentSubscriptionModification();
+        }
+
+        // Cannot remove price feeds from a permanent subscription
+        if (newParams.priceIds.length < currentParams.priceIds.length) {
+            revert IllegalPermanentSubscriptionModification();
+        }
+
+        // Check that all existing price IDs are preserved (adding is allowed, not removing)
+        for (uint i = 0; i < currentParams.priceIds.length; i++) {
+            bool found = false;
+            for (uint j = 0; j < newParams.priceIds.length; j++) {
+                if (currentParams.priceIds[i] == newParams.priceIds[j]) {
+                    found = true;
+                    break;
+                }
+            }
+            if (!found) {
+                revert IllegalPermanentSubscriptionModification();
+            }
+        }
+
+        // Cannot change reader whitelist settings for permanent subscriptions
+        if (newParams.whitelistEnabled != currentParams.whitelistEnabled) {
+            revert IllegalPermanentSubscriptionModification();
+        }
+
+        // Check if the set of addresses in the whitelist is the same
+        if (
+            newParams.readerWhitelist.length !=
+            currentParams.readerWhitelist.length
+        ) {
+            revert IllegalPermanentSubscriptionModification();
+        }
+        uint256 n = newParams.readerWhitelist.length;
+        bool[] memory currentVisited = new bool[](n);
+        uint256 matchesFound = 0;
+        for (uint256 i = 0; i < n; i++) {
+            bool foundInCurrent = false;
+            for (uint256 j = 0; j < n; j++) {
+                if (
+                    !currentVisited[j] &&
+                    newParams.readerWhitelist[i] ==
+                    currentParams.readerWhitelist[j]
+                ) {
+                    currentVisited[j] = true;
+                    foundInCurrent = true;
+                    matchesFound++;
+                    break;
+                }
+            }
+            if (!foundInCurrent) {
+                revert IllegalPermanentSubscriptionModification();
+            }
+        }
+
+        // Cannot change update criteria for permanent subscriptions
+        if (
+            newParams.updateCriteria.updateOnHeartbeat !=
+            currentParams.updateCriteria.updateOnHeartbeat ||
+            newParams.updateCriteria.heartbeatSeconds !=
+            currentParams.updateCriteria.heartbeatSeconds ||
+            newParams.updateCriteria.updateOnDeviation !=
+            currentParams.updateCriteria.updateOnDeviation ||
+            newParams.updateCriteria.deviationThresholdBps !=
+            currentParams.updateCriteria.deviationThresholdBps
+        ) {
+            revert IllegalPermanentSubscriptionModification();
+        }
+
+        // Cannot change gas config for permanent subscriptions
+        if (
+            newParams.gasConfig.maxBaseFeeMultiplierCapPct !=
+            currentParams.gasConfig.maxBaseFeeMultiplierCapPct ||
+            newParams.gasConfig.maxPriorityFeeMultiplierCapPct !=
+            currentParams.gasConfig.maxPriorityFeeMultiplierCapPct
+        ) {
+            revert IllegalPermanentSubscriptionModification();
+        }
+    }
+
     /// FETCH PRICES
 
     /**
@@ -487,9 +589,7 @@ abstract contract Scheduler is IScheduler, SchedulerState {
 
     /// BALANCE MANAGEMENT
 
-    function addFunds(
-        uint256 subscriptionId
-    ) external payable override onlyManager(subscriptionId) {
+    function addFunds(uint256 subscriptionId) external payable override {
         if (!_state.subscriptionParams[subscriptionId].isActive) {
             revert InactiveSubscription();
         }
@@ -508,6 +608,11 @@ abstract contract Scheduler is IScheduler, SchedulerState {
             subscriptionId
         ];
 
+        // Prevent withdrawals from permanent subscriptions
+        if (params.isPermanent) {
+            revert IllegalPermanentSubscriptionModification();
+        }
+
         if (status.balanceInWei < amount) {
             revert InsufficientBalance();
         }

target_chains/ethereum/contracts/contracts/pulse/scheduler/SchedulerErrors.sol

@@ -12,6 +12,7 @@ error InvalidGasConfig();
 error PriceSlotMismatch();
 error TooManyPriceIds(uint256 provided, uint256 maximum);
 error UpdateConditionsNotMet();
+error IllegalPermanentSubscriptionModification();
 error TimestampOlderThanLastUpdate(
     uint256 providedUpdateTimestamp,
     uint256 lastUpdatedAt

target_chains/ethereum/contracts/contracts/pulse/scheduler/SchedulerState.sol

@@ -41,6 +41,7 @@ contract SchedulerState {
         address[] readerWhitelist;
         bool whitelistEnabled;
         bool isActive;
+        bool isPermanent;
         UpdateCriteria updateCriteria;
         GasConfig gasConfig;
     }