refactor: account for isTimeBased reverting

subgraphs/isolated-pools/schema.graphql

@@ -250,6 +250,7 @@ type RewardsDistributor @entity {
     rewardTokenAddress: Bytes!
     "Distribution rate for suppliers"
     marketRewards: [MarketReward!]! @derivedFrom(field:"rewardsDistributor")
+    "Depending on the Chain, the rewards distributor is time based or block based"
     isTimeBased: Boolean!
 }
 

subgraphs/isolated-pools/src/operations/create.ts

@@ -48,6 +48,7 @@ import {
   getRewardsDistributorId,
   getTransactionEventId,
 } from '../utilities/ids';
+import valueOrFalseIfReverted from '../utilities/valueOrFalseIfReverted';
 
 export function createPool(comptroller: Address): Pool {
   const pool = new Pool(getPoolId(comptroller));
@@ -311,7 +312,9 @@ export function createRewardDistributor(
   rewardsDistributor.address = rewardsDistributorAddress;
   rewardsDistributor.pool = comptrollerAddress;
   rewardsDistributor.rewardTokenAddress = rewardToken;
-  rewardsDistributor.isTimeBased = rewardDistributorContract.isTimeBased();
+  rewardsDistributor.isTimeBased = valueOrFalseIfReverted(
+    rewardDistributorContract.try_isTimeBased(),
+  );
   rewardsDistributor.save();
 
   // we get the current speeds for all known markets at this point in time

subgraphs/isolated-pools/src/utilities/valueOrFalseIfReverted.ts

@@ -0,0 +1,8 @@
+import { ethereum } from '@graphprotocol/graph-ts';
+
+// checks if a call reverted, in case it is we return -1 to indicate the wanted value is not available
+function valueOrFalseIfReverted(callResult: ethereum.CallResult<boolean>): boolean {
+  return callResult.reverted ? false : callResult.value;
+}
+
+export default valueOrFalseIfReverted;