Make block/epoch alignment in tests more predictable (#555)

- Change the advanceToNextEpoch function to always advance to the first block in the next epoch, rather than always advancing a full epoch
- Change several tests that advanced an epochLength to use advanceToNextEpoch instead
- In takeRewards tests that expect an amount for indexer rewards, align to the first block in an epoch and recalculate the expected rewards using the number of blocks, that is now a bit easier to calculate by just counting the number of transactions in the test code.

Author: pcarranzav

test/lib/testHelpers.ts

@@ -74,14 +74,13 @@ export const advanceBlocks = async (blocks: string | number | BigNumber): Promis
   const steps = typeof blocks === 'number' || typeof blocks === 'string' ? toBN(blocks) : blocks
   const currentBlock = await latestBlock()
   const toBlock = currentBlock.add(steps)
-  await advanceBlockTo(toBlock)
+  return advanceBlockTo(toBlock)
 }
 
 export const advanceToNextEpoch = async (epochManager: EpochManager): Promise<void> => {
-  const currentBlock = await latestBlock()
-  const epochLength = await epochManager.epochLength()
-  const nextEpochBlock = currentBlock.add(epochLength)
-  await advanceBlockTo(nextEpochBlock)
+  const blocksSinceEpoch = await epochManager.currentEpochBlockSinceStart()
+  const epochLen = await epochManager.epochLength()
+  return advanceBlocks(epochLen.sub(blocksSinceEpoch))
 }
 
 export const evmSnapshot = async (): Promise<number> => provider().send('evm_snapshot', [])

test/rewards/rewards.test.ts

@@ -573,19 +573,29 @@ describe('Rewards', () => {
       }
 
       it('should distribute rewards on closed allocation and stake', async function () {
+
+        // Align with the epoch boundary
+        await advanceToNextEpoch(epochManager)
         // Setup
         await setupIndexerAllocation()
 
         // Jump
-        await advanceBlocks(await epochManager.epochLength())
+        await advanceToNextEpoch(epochManager)
 
         // Before state
         const beforeTokenSupply = await grt.totalSupply()
         const beforeIndexer1Stake = await staking.getIndexerStakedTokens(indexer1.address)
         const beforeIndexer1Balance = await grt.balanceOf(indexer1.address)
         const beforeStakingBalance = await grt.balanceOf(staking.address)
 
-        const expectedIndexingRewards = toGRT('1471954234')
+        // All the rewards in this subgraph go to this allocation.
+        // Rewards per token will be (totalSupply * issuanceRate^nBlocks - totalSupply) / allocatedTokens
+        // The first snapshot is after allocating, that is 2 blocks after the signal is minted:
+        // startRewardsPerToken = (10004000000 * 1.01227 ^ 2 - 10004000000) / 12500 = 122945.16
+        // The final snapshot is when we close the allocation, that happens 9 blocks later:
+        // endRewardsPerToken = (10004000000 * 1.01227 ^ 9 - 10004000000) / 12500 = 92861.24
+        // Then our expected rewards are (endRewardsPerToken - startRewardsPerToken) * 12500.
+        const expectedIndexingRewards = toGRT('913715958')
 
         // Close allocation. At this point rewards should be collected for that indexer
         const tx = await staking
@@ -623,19 +633,28 @@ describe('Rewards', () => {
         const destinationAddress = randomHexBytes(20)
         await staking.connect(indexer1.signer).setRewardsDestination(destinationAddress)
 
+        // Align with the epoch boundary
+        await advanceToNextEpoch(epochManager)
         // Setup
         await setupIndexerAllocation()
 
         // Jump
-        await advanceBlocks(await epochManager.epochLength())
+        await advanceToNextEpoch(epochManager)
 
         // Before state
         const beforeTokenSupply = await grt.totalSupply()
         const beforeIndexer1Stake = await staking.getIndexerStakedTokens(indexer1.address)
         const beforeDestinationBalance = await grt.balanceOf(destinationAddress)
         const beforeStakingBalance = await grt.balanceOf(staking.address)
 
-        const expectedIndexingRewards = toGRT('1471954234')
+        // All the rewards in this subgraph go to this allocation.
+        // Rewards per token will be (totalSupply * issuanceRate^nBlocks - totalSupply) / allocatedTokens
+        // The first snapshot is after allocating, that is 2 blocks after the signal is minted:
+        // startRewardsPerToken = (10004000000 * 1.01227 ^ 2 - 10004000000) / 12500 = 122945.16
+        // The final snapshot is when we close the allocation, that happens 9 blocks later:
+        // endRewardsPerToken = (10004000000 * 1.01227 ^ 9 - 10004000000) / 12500 = 92861.24
+        // Then our expected rewards are (endRewardsPerToken - startRewardsPerToken) * 12500.
+        const expectedIndexingRewards = toGRT('913715958')
 
         // Close allocation. At this point rewards should be collected for that indexer
         const tx = await staking
@@ -678,10 +697,13 @@ describe('Rewards', () => {
         }
         const tokensToDelegate = toGRT('2000')
 
+        // Align with the epoch boundary
+        await advanceToNextEpoch(epochManager)
+        // Setup the allocation and delegators
         await setupIndexerAllocationWithDelegation(tokensToDelegate, delegationParams)
 
         // Jump
-        await advanceBlocks(await epochManager.epochLength())
+        await advanceToNextEpoch(epochManager)
 
         // Before state
         const beforeTokenSupply = await grt.totalSupply()
@@ -698,8 +720,15 @@ describe('Rewards', () => {
 
         // Check that rewards are put into indexer stake (only indexer cut)
         // Check that rewards are put into delegators pool accordingly
-        // NOTE: calculated manually on a spreadsheet
-        const expectedIndexingRewards = toGRT('1454109066')
+
+        // All the rewards in this subgraph go to this allocation.
+        // Rewards per token will be (totalSupply * issuanceRate^nBlocks - totalSupply) / allocatedTokens
+        // The first snapshot is after allocating, that is 2 blocks after the signal is minted:
+        // startRewardsPerToken = (10004000000 * 1.01227 ^ 2 - 10004000000) / 14500 = 8466.995
+        // The final snapshot is when we close the allocation, that happens 4 blocks later:
+        // endRewardsPerToken = (10004000000 * 1.01227 ^ 4 - 10004000000) / 14500 = 34496.55
+        // Then our expected rewards are (endRewardsPerToken - startRewardsPerToken) * 14500.
+        const expectedIndexingRewards = toGRT('377428566.77')
         // Calculate delegators cut
         const indexerRewards = delegationParams.indexingRewardCut
           .mul(expectedIndexingRewards)
@@ -725,7 +754,7 @@ describe('Rewards', () => {
         await setupIndexerAllocation()
 
         // Jump
-        await advanceBlocks(await epochManager.epochLength())
+        await advanceToNextEpoch(epochManager)
 
         // Close allocation. At this point rewards should be collected for that indexer
         const tx = staking.connect(indexer1.signer).closeAllocation(allocationID, randomHexBytes())
@@ -769,7 +798,7 @@ describe('Rewards', () => {
         )
 
       // Jump
-      await advanceBlocks(await epochManager.epochLength())
+      await advanceToNextEpoch(epochManager)
 
       // Remove all signal from the subgraph
       const curatorShares = await curation.getCuratorSignal(curator1.address, subgraphDeploymentID1)