Fix delegation claim syncing (#889)

* sync claims on validator state changes and slashes

* add test notes

* update missed sync delegator calls

* tidy up suite addresses initialization

* test claim synced when validator bonds/unbonds

* test validator slashed

* check reward factor increased

* test redelegation sync claim

* revert mistake

* resolve trailing TODOs

* call incentive hooks after hard liquidation

* check global index in tests after delegator reward sync

Co-authored-by: denalimarsh <denalimarsh@gmail.com>
Co-authored-by: karzak <kjydavis3@gmail.com>

x/hard/keeper/liquidation.go

@@ -61,8 +61,13 @@ func (k Keeper) AttemptKeeperLiquidation(ctx sdk.Context, keeper sdk.AccAddress,
 		return err
 	}
 
+	deposit.Amount = sdk.NewCoins()
 	k.DeleteDeposit(ctx, deposit)
+	k.AfterDepositModified(ctx, deposit)
+
+	borrow.Amount = sdk.NewCoins()
 	k.DeleteBorrow(ctx, borrow)
+	k.AfterBorrowModified(ctx, borrow)
 	return nil
 }
 

x/incentive/keeper/hooks.go

@@ -66,30 +66,69 @@ func (h Hooks) AfterBorrowModified(ctx sdk.Context, borrow hardtypes.Borrow) {
 	h.k.UpdateHardBorrowIndexDenoms(ctx, borrow)
 }
 
-// ------------------- Staking Module Hooks -------------------
+/* ------------------- Staking Module Hooks -------------------
+
+Rewards are calculated based on total delegated tokens to bonded validators (not shares).
+We need to sync the claim before the user's delegated tokens are changed.
+
+When delegated tokens (to bonded validators) are changed:
+- user creates new delegation
+  - total bonded delegation increases
+- user delegates or beginUnbonding or beginRedelegate an existing delegation
+  - total bonded delegation increases or decreases
+- validator is slashed and Jailed/Tombstoned (tokens reduce, and validator is unbonded)
+  - slash: total bonded delegation decreases (less tokens)
+  - jail: total bonded delegation decreases (tokens no longer bonded (after end blocker runs))
+- validator becomes unbonded (ie when they drop out of the top 100)
+  - total bonded delegation decreases (tokens no longer bonded)
+
+*/
 
 // BeforeDelegationCreated runs before a delegation is created
 func (h Hooks) BeforeDelegationCreated(ctx sdk.Context, delAddr sdk.AccAddress, valAddr sdk.ValAddress) {
+	// Add a claim if one doesn't exist, otherwise sync the existing.
 	h.k.InitializeHardDelegatorReward(ctx, delAddr)
 }
 
 // BeforeDelegationSharesModified runs before an existing delegation is modified
 func (h Hooks) BeforeDelegationSharesModified(ctx sdk.Context, delAddr sdk.AccAddress, valAddr sdk.ValAddress) {
-	h.k.SynchronizeHardDelegatorRewards(ctx, delAddr)
+	// Sync rewards based on total delegated to bonded validators.
+	h.k.SynchronizeHardDelegatorRewards(ctx, delAddr, nil, false)
 }
 
-// NOTE: following hooks are just implemented to ensure StakingHooks interface compliance
-
 // BeforeValidatorSlashed is called before a validator is slashed
-func (h Hooks) BeforeValidatorSlashed(ctx sdk.Context, valAddr sdk.ValAddress, fraction sdk.Dec) {}
+// Validator status is not updated when Slash or Jail is called
+func (h Hooks) BeforeValidatorSlashed(ctx sdk.Context, valAddr sdk.ValAddress, fraction sdk.Dec) {
+	// Sync all claims for users delegated to this validator.
+	// For each claim, sync based on the total delegated to bonded validators.
+	for _, delegation := range h.k.stakingKeeper.GetValidatorDelegations(ctx, valAddr) {
+		h.k.SynchronizeHardDelegatorRewards(ctx, delegation.DelegatorAddress, nil, false)
+	}
+}
 
 // AfterValidatorBeginUnbonding is called after a validator begins unbonding
+// Validator status is set to Unbonding prior to hook running
 func (h Hooks) AfterValidatorBeginUnbonding(ctx sdk.Context, consAddr sdk.ConsAddress, valAddr sdk.ValAddress) {
+	// Sync all claims for users delegated to this validator.
+	// For each claim, sync based on the total delegated to bonded validators, and also delegations to valAddr.
+	// valAddr's status has just been set to Unbonding, but we want to include delegations to it in the sync.
+	for _, delegation := range h.k.stakingKeeper.GetValidatorDelegations(ctx, valAddr) {
+		h.k.SynchronizeHardDelegatorRewards(ctx, delegation.DelegatorAddress, valAddr, true)
+	}
 }
 
 // AfterValidatorBonded is called after a validator is bonded
+// Validator status is set to Bonded prior to hook running
 func (h Hooks) AfterValidatorBonded(ctx sdk.Context, consAddr sdk.ConsAddress, valAddr sdk.ValAddress) {
+	// Sync all claims for users delegated to this validator.
+	// For each claim, sync based on the total delegated to bonded validators, except for delegations to valAddr.
+	// valAddr's status has just been set to Bonded, but we don't want to include delegations to it in the sync
+	for _, delegation := range h.k.stakingKeeper.GetValidatorDelegations(ctx, valAddr) {
+		h.k.SynchronizeHardDelegatorRewards(ctx, delegation.DelegatorAddress, valAddr, false)
 	}
+}
+
+// NOTE: following hooks are just implemented to ensure StakingHooks interface compliance
 
 // AfterDelegationModified runs after a delegation is modified
 func (h Hooks) AfterDelegationModified(ctx sdk.Context, delAddr sdk.AccAddress, valAddr sdk.ValAddress) {

x/incentive/keeper/integration_test.go

@@ -209,20 +209,11 @@ func NewStakingGenesisState() app.GenesisState {
 }
 
 func (suite *KeeperTestSuite) SetupWithGenState() {
-	config := sdk.GetConfig()
-	app.SetBech32AddressPrefixes(config)
-
-	_, allAddrs := app.GeneratePrivKeyAddressPairs(10)
-	suite.addrs = allAddrs[:5]
-	for _, a := range allAddrs[5:] {
-		suite.validatorAddrs = append(suite.validatorAddrs, sdk.ValAddress(a))
-	}
-
 	tApp := app.NewTestApp()
 	ctx := tApp.NewContext(true, abci.Header{Height: 1, Time: tmtime.Now()})
 
 	tApp.InitializeFromGenesisStates(
-		NewAuthGenState(allAddrs, cs(c("ukava", 1_000_000_000))),
+		NewAuthGenState(suite.getAllAddrs(), cs(c("ukava", 1_000_000_000))),
 		NewStakingGenesisState(),
 		NewPricefeedGenStateMulti(),
 		NewCDPGenStateMulti(),

x/incentive/keeper/keeper_test.go

@@ -38,17 +38,33 @@ type KeeperTestSuite struct {
 
 // The default state used by each test
 func (suite *KeeperTestSuite) SetupTest() {
+	config := sdk.GetConfig()
+	app.SetBech32AddressPrefixes(config)
+
+	_, allAddrs := app.GeneratePrivKeyAddressPairs(10)
+	suite.addrs = allAddrs[:5]
+	for _, a := range allAddrs[5:] {
+		suite.validatorAddrs = append(suite.validatorAddrs, sdk.ValAddress(a))
+	}
+
 	tApp := app.NewTestApp()
 	ctx := tApp.NewContext(true, abci.Header{Height: 1, Time: tmtime.Now()})
 
 	tApp.InitializeFromGenesisStates()
 
-	_, addrs := app.GeneratePrivKeyAddressPairs(5)
-	keeper := tApp.GetIncentiveKeeper()
+	suite.keeper = tApp.GetIncentiveKeeper()
 	suite.app = tApp
 	suite.ctx = ctx
-	suite.keeper = keeper
-	suite.addrs = addrs
+}
+
+// getAllAddrs returns all user and validator addresses in the suite
+func (suite *KeeperTestSuite) getAllAddrs() []sdk.AccAddress {
+	accAddrs := []sdk.AccAddress{} // initialize new slice to avoid accidental modifications to underlying
+	accAddrs = append(accAddrs, suite.addrs...)
+	for _, a := range suite.validatorAddrs {
+		accAddrs = append(accAddrs, sdk.AccAddress(a))
+	}
+	return accAddrs
 }
 
 func (suite *KeeperTestSuite) getAccount(addr sdk.AccAddress) authexported.Account {

x/incentive/keeper/rewards.go

@@ -271,10 +271,7 @@ func (k Keeper) InitializeHardSupplyReward(ctx sdk.Context, deposit hardtypes.De
 	}
 
 	claim, found := k.GetHardLiquidityProviderClaim(ctx, deposit.Depositor)
-	if found {
-		// Reset borrow reward indexes
-		claim.BorrowRewardIndexes = types.MultiRewardIndexes{}
-	} else {
+	if !found {
 		// Instantiate claim object
 		claim = types.NewHardLiquidityProviderClaim(deposit.Depositor, sdk.Coins{}, nil, nil, nil)
 	}
@@ -496,8 +493,10 @@ func (k Keeper) UpdateHardBorrowIndexDenoms(ctx sdk.Context, borrow hardtypes.Bo
 	k.SetHardLiquidityProviderClaim(ctx, claim)
 }
 
-// SynchronizeHardDelegatorRewards updates the claim object by adding any accumulated rewards
-func (k Keeper) SynchronizeHardDelegatorRewards(ctx sdk.Context, delegator sdk.AccAddress) {
+// SynchronizeHardDelegatorRewards updates the claim object by adding any accumulated rewards, and setting the reward indexes to the global values.
+// valAddr and shouldIncludeValidator are used to ignore or include delegations to a particular validator when summing up the total delegation.
+// Normally only delegations to Bonded validators are included in the total. This is needed as staking hooks are sometimes called on the wrong side of a validator's state update (from this module's perspective).
+func (k Keeper) SynchronizeHardDelegatorRewards(ctx sdk.Context, delegator sdk.AccAddress, valAddr sdk.ValAddress, shouldIncludeValidator bool) {
 	claim, found := k.GetHardLiquidityProviderClaim(ctx, delegator)
 	if !found {
 		return
@@ -529,10 +528,17 @@ func (k Keeper) SynchronizeHardDelegatorRewards(ctx sdk.Context, delegator sdk.A
 			continue
 		}
 
-		// Delegators don't accumulate rewards if their validator is unbonded/slashed
+		if valAddr == nil {
+			// Delegators don't accumulate rewards if their validator is unbonded
 			if validator.GetStatus() != sdk.Bonded {
 				continue
 			}
+		} else {
+			if !shouldIncludeValidator && validator.OperatorAddress.Equals(valAddr) {
+				// ignore tokens delegated to the validator
+				continue
+			}
+		}
 
 		if validator.GetTokens().IsZero() {
 			continue
@@ -601,7 +607,7 @@ func (k Keeper) InitializeHardDelegatorReward(ctx sdk.Context, delegator sdk.Acc
 		// Instantiate claim object
 		claim = types.NewHardLiquidityProviderClaim(delegator, sdk.Coins{}, nil, nil, nil)
 	} else {
-		k.SynchronizeHardDelegatorRewards(ctx, delegator)
+		k.SynchronizeHardDelegatorRewards(ctx, delegator, nil, false)
 		claim, _ = k.GetHardLiquidityProviderClaim(ctx, delegator)
 	}
 
@@ -652,7 +658,7 @@ func (k Keeper) SynchronizeHardLiquidityProviderClaim(ctx sdk.Context, owner sdk
 	}
 
 	// Synchronize any hard delegator rewards
-	k.SynchronizeHardDelegatorRewards(ctx, owner)
+	k.SynchronizeHardDelegatorRewards(ctx, owner, nil, false)
 }
 
 // ZeroHardLiquidityProviderClaim zeroes out the claim object's rewards and returns the updated claim object

x/incentive/keeper/rewards_test.go

@@ -16,6 +16,10 @@ import (
 	"github.com/kava-labs/kava/x/incentive/types"
 )
 
+const (
+	oneYear time.Duration = time.Hour * 24 * 365
+)
+
 func (suite *KeeperTestSuite) TestAccumulateUSDXMintingRewards() {
 	type args struct {
 		ctype                 string
@@ -885,7 +889,7 @@ func (suite *KeeperTestSuite) TestAccumulateHardDelegatorRewards() {
 
 			err := suite.deliverMsgCreateValidator(suite.ctx, suite.validatorAddrs[0], tc.args.delegation)
 			suite.Require().NoError(err)
-			suite.deliverMsgDelegate(suite.ctx, suite.addrs[0], suite.validatorAddrs[0], tc.args.delegation)
+			err = suite.deliverMsgDelegate(suite.ctx, suite.addrs[0], suite.validatorAddrs[0], tc.args.delegation)
 			suite.Require().NoError(err)
 
 			staking.EndBlocker(suite.ctx, suite.stakingKeeper)
@@ -2407,7 +2411,7 @@ func (suite *KeeperTestSuite) TestSynchronizeHardDelegatorReward() {
 
 			// After we've accumulated, run synchronize
 			suite.Require().NotPanics(func() {
-				suite.keeper.SynchronizeHardDelegatorRewards(suite.ctx, suite.addrs[0])
+				suite.keeper.SynchronizeHardDelegatorRewards(suite.ctx, suite.addrs[0], nil, false)
 			})
 
 			// Check that reward factor and claim have been updated as expected
@@ -2767,7 +2771,7 @@ func (suite *KeeperTestSuite) TestSimulateHardDelegatorRewardSynchronization() {
 			// Delegator delegates
 			err := suite.deliverMsgCreateValidator(suite.ctx, suite.validatorAddrs[0], tc.args.delegation)
 			suite.Require().NoError(err)
-			suite.deliverMsgDelegate(suite.ctx, suite.addrs[0], suite.validatorAddrs[0], tc.args.delegation)
+			err = suite.deliverMsgDelegate(suite.ctx, suite.addrs[0], suite.validatorAddrs[0], tc.args.delegation)
 			suite.Require().NoError(err)
 
 			staking.EndBlocker(suite.ctx, suite.stakingKeeper)
@@ -2944,3 +2948,348 @@ func (suite *KeeperTestSuite) deliverMsgDelegate(ctx sdk.Context, delegator sdk.
 	_, err := handleStakingMsg(ctx, msg)
 	return err
 }
+
+func (suite *KeeperTestSuite) deliverMsgRedelegate(ctx sdk.Context, delegator sdk.AccAddress, sourceValidator, destinationValidator sdk.ValAddress, amount sdk.Coin) error {
+	msg := staking.NewMsgBeginRedelegate(
+		delegator,
+		sourceValidator,
+		destinationValidator,
+		amount,
+	)
+	handleStakingMsg := staking.NewHandler(suite.stakingKeeper)
+	_, err := handleStakingMsg(ctx, msg)
+	return err
+}
+
+// given a user has a delegation to a bonded validator, when the validator starts unbonding, the user does not accumulate rewards
+func (suite *KeeperTestSuite) TestUnbondingValidatorSyncsClaim() {
+	suite.SetupWithGenState()
+	initialTime := time.Date(2020, 12, 15, 14, 0, 0, 0, time.UTC)
+	suite.ctx = suite.ctx.WithBlockTime(initialTime)
+	blockDuration := 10 * time.Second
+
+	// Setup incentive state
+	rewardsPerSecond := c("hard", 122354)
+	bondDenom := "ukava"
+	params := types.NewParams(
+		nil,
+		nil,
+		nil,
+		types.RewardPeriods{
+			types.NewRewardPeriod(true, bondDenom, initialTime.Add(-1*oneYear), initialTime.Add(4*oneYear), rewardsPerSecond),
+		},
+		types.DefaultMultipliers,
+		initialTime.Add(5*oneYear),
+	)
+	suite.keeper.SetParams(suite.ctx, params)
+	suite.keeper.SetPreviousHardDelegatorRewardAccrualTime(suite.ctx, bondDenom, initialTime)
+	suite.keeper.SetHardDelegatorRewardFactor(suite.ctx, bondDenom, sdk.ZeroDec())
+
+	// Reduce the size of the validator set
+	stakingParams := suite.app.GetStakingKeeper().GetParams(suite.ctx)
+	stakingParams.MaxValidators = 2
+	suite.app.GetStakingKeeper().SetParams(suite.ctx, stakingParams)
+
+	// Create 3 validators
+	err := suite.deliverMsgCreateValidator(suite.ctx, suite.validatorAddrs[0], c(bondDenom, 10_000_000))
+	suite.Require().NoError(err)
+	err = suite.deliverMsgCreateValidator(suite.ctx, suite.validatorAddrs[1], c(bondDenom, 5_000_000))
+	suite.Require().NoError(err)
+	err = suite.deliverMsgCreateValidator(suite.ctx, suite.validatorAddrs[2], c(bondDenom, 1_000_000))
+	suite.Require().NoError(err)
+
+	// End the block so top validators become bonded
+	_ = suite.app.EndBlocker(suite.ctx, abci.RequestEndBlock{})
+
+	suite.ctx = suite.ctx.WithBlockTime(initialTime.Add(1 * blockDuration))
+	_ = suite.app.BeginBlocker(suite.ctx, abci.RequestBeginBlock{}) // height and time in header are ignored by module begin blockers
+
+	// Delegate to a bonded validator from the test user. This will initialize their incentive claim.
+	err = suite.deliverMsgDelegate(suite.ctx, suite.addrs[0], suite.validatorAddrs[1], c(bondDenom, 1_000_000))
+	suite.Require().NoError(err)
+
+	// Start a new block to accumulate some delegation rewards for the user.
+	_ = suite.app.EndBlocker(suite.ctx, abci.RequestEndBlock{})
+	suite.ctx = suite.ctx.WithBlockTime(initialTime.Add(2 * blockDuration))
+	_ = suite.app.BeginBlocker(suite.ctx, abci.RequestBeginBlock{}) // height and time in header are ignored by module begin blockers
+
+	// Delegate to the unbonded validator to push it into the bonded validator set, pushing out the user's delegated validator
+	err = suite.deliverMsgDelegate(suite.ctx, suite.addrs[2], suite.validatorAddrs[2], c(bondDenom, 8_000_000))
+	suite.Require().NoError(err)
+
+	// End the block to start unbonding the user's validator
+	_ = suite.app.EndBlocker(suite.ctx, abci.RequestEndBlock{})
+	// but don't start the next block as it will accumulate delegator rewards and we won't be able to tell if the user's reward was synced.
+
+	// Check that the user's claim has been synced. ie rewards added, index updated
+	claim, found := suite.keeper.GetHardLiquidityProviderClaim(suite.ctx, suite.addrs[0])
+	suite.Require().True(found)
+
+	globalIndex, found := suite.keeper.GetHardDelegatorRewardFactor(suite.ctx, bondDenom)
+	suite.Require().True(found)
+	claimIndex, found := claim.DelegatorRewardIndexes.GetRewardIndex(bondDenom)
+	suite.Require().True(found)
+	suite.Require().Equal(globalIndex, claimIndex.RewardFactor)
+
+	suite.Require().Equal(
+		cs(c(rewardsPerSecond.Denom, 76471)),
+		claim.Reward,
+	)
+
+	// Run another block and check the claim is not accumulating more rewards
+	suite.ctx = suite.ctx.WithBlockTime(initialTime.Add(3 * blockDuration))
+	_ = suite.app.BeginBlocker(suite.ctx, abci.RequestBeginBlock{})
+
+	suite.keeper.SynchronizeHardDelegatorRewards(suite.ctx, suite.addrs[0], nil, false)
+
+	// rewards are the same as before
+	laterClaim, found := suite.keeper.GetHardLiquidityProviderClaim(suite.ctx, suite.addrs[0])
+	suite.Require().True(found)
+	suite.Require().Equal(claim.Reward, laterClaim.Reward)
+
+	// claim index has been updated to latest global value
+	laterClaimIndex, found := laterClaim.DelegatorRewardIndexes.GetRewardIndex(bondDenom)
+	suite.Require().True(found)
+	globalIndex, found = suite.keeper.GetHardDelegatorRewardFactor(suite.ctx, bondDenom)
+	suite.Require().True(found)
+	suite.Require().Equal(globalIndex, laterClaimIndex.RewardFactor)
+}
+
+// given a user has a delegation to an unbonded validator, when the validator becomes bonded, the user starts accumulating rewards
+func (suite *KeeperTestSuite) TestBondingValidatorSyncsClaim() {
+	suite.SetupWithGenState()
+	initialTime := time.Date(2020, 12, 15, 14, 0, 0, 0, time.UTC)
+	suite.ctx = suite.ctx.WithBlockTime(initialTime)
+	blockDuration := 10 * time.Second
+
+	// Setup incentive state
+	rewardsPerSecond := c("hard", 122354)
+	bondDenom := "ukava"
+	params := types.NewParams(
+		nil,
+		nil,
+		nil,
+		types.RewardPeriods{
+			types.NewRewardPeriod(true, bondDenom, initialTime.Add(-1*oneYear), initialTime.Add(4*oneYear), rewardsPerSecond),
+		},
+		types.DefaultMultipliers,
+		initialTime.Add(5*oneYear),
+	)
+	suite.keeper.SetParams(suite.ctx, params)
+	suite.keeper.SetPreviousHardDelegatorRewardAccrualTime(suite.ctx, bondDenom, initialTime)
+	suite.keeper.SetHardDelegatorRewardFactor(suite.ctx, bondDenom, sdk.ZeroDec())
+
+	// Reduce the size of the validator set
+	stakingParams := suite.app.GetStakingKeeper().GetParams(suite.ctx)
+	stakingParams.MaxValidators = 2
+	suite.app.GetStakingKeeper().SetParams(suite.ctx, stakingParams)
+
+	// Create 3 validators
+	err := suite.deliverMsgCreateValidator(suite.ctx, suite.validatorAddrs[0], c(bondDenom, 10_000_000))
+	suite.Require().NoError(err)
+	err = suite.deliverMsgCreateValidator(suite.ctx, suite.validatorAddrs[1], c(bondDenom, 5_000_000))
+	suite.Require().NoError(err)
+	err = suite.deliverMsgCreateValidator(suite.ctx, suite.validatorAddrs[2], c(bondDenom, 1_000_000))
+	suite.Require().NoError(err)
+
+	// End the block so top validators become bonded
+	_ = suite.app.EndBlocker(suite.ctx, abci.RequestEndBlock{})
+
+	suite.ctx = suite.ctx.WithBlockTime(initialTime.Add(1 * blockDuration))
+	_ = suite.app.BeginBlocker(suite.ctx, abci.RequestBeginBlock{}) // height and time in header are ignored by module begin blockers
+
+	// Delegate to an unbonded validator from the test user. This will initialize their incentive claim.
+	err = suite.deliverMsgDelegate(suite.ctx, suite.addrs[0], suite.validatorAddrs[2], c(bondDenom, 1_000_000))
+	suite.Require().NoError(err)
+
+	// Start a new block to accumulate some delegation rewards globally.
+	_ = suite.app.EndBlocker(suite.ctx, abci.RequestEndBlock{})
+	suite.ctx = suite.ctx.WithBlockTime(initialTime.Add(2 * blockDuration))
+	_ = suite.app.BeginBlocker(suite.ctx, abci.RequestBeginBlock{})
+
+	// Delegate to the user's unbonded validator to push it into the bonded validator set
+	err = suite.deliverMsgDelegate(suite.ctx, suite.addrs[2], suite.validatorAddrs[2], c(bondDenom, 4_000_000))
+	suite.Require().NoError(err)
+
+	// End the block to bond the user's validator
+	_ = suite.app.EndBlocker(suite.ctx, abci.RequestEndBlock{})
+	// but don't start the next block as it will accumulate delegator rewards and we won't be able to tell if the user's reward was synced.
+
+	// Check that the user's claim has been synced. ie rewards added, index updated
+	claim, found := suite.keeper.GetHardLiquidityProviderClaim(suite.ctx, suite.addrs[0])
+	suite.Require().True(found)
+
+	globalIndex, found := suite.keeper.GetHardDelegatorRewardFactor(suite.ctx, bondDenom)
+	suite.Require().True(found)
+	claimIndex, found := claim.DelegatorRewardIndexes.GetRewardIndex(bondDenom)
+	suite.Require().True(found)
+	suite.Require().Equal(globalIndex, claimIndex.RewardFactor)
+
+	suite.Require().Equal(
+		sdk.Coins(nil),
+		claim.Reward,
+	)
+
+	// Run another block and check the claim is accumulating more rewards
+	suite.ctx = suite.ctx.WithBlockTime(initialTime.Add(3 * blockDuration))
+	_ = suite.app.BeginBlocker(suite.ctx, abci.RequestBeginBlock{})
+
+	suite.keeper.SynchronizeHardDelegatorRewards(suite.ctx, suite.addrs[0], nil, false)
+
+	// rewards are greater than before
+	laterClaim, found := suite.keeper.GetHardLiquidityProviderClaim(suite.ctx, suite.addrs[0])
+	suite.Require().True(found)
+	suite.Require().True(laterClaim.Reward.IsAllGT(claim.Reward))
+
+	// claim index has been updated to latest global value
+	laterClaimIndex, found := laterClaim.DelegatorRewardIndexes.GetRewardIndex(bondDenom)
+	suite.Require().True(found)
+	globalIndex, found = suite.keeper.GetHardDelegatorRewardFactor(suite.ctx, bondDenom)
+	suite.Require().True(found)
+	suite.Require().Equal(globalIndex, laterClaimIndex.RewardFactor)
+}
+
+// If a validator is slashed delegators should have their claims synced
+func (suite *KeeperTestSuite) TestSlashingValidatorSyncsClaim() {
+	suite.SetupWithGenState()
+	initialTime := time.Date(2020, 12, 15, 14, 0, 0, 0, time.UTC)
+	suite.ctx = suite.ctx.WithBlockTime(initialTime)
+	blockDuration := 10 * time.Second
+
+	// Setup incentive state
+	rewardsPerSecond := c("hard", 122354)
+	bondDenom := "ukava"
+	params := types.NewParams(
+		nil,
+		nil,
+		nil,
+		types.RewardPeriods{
+			types.NewRewardPeriod(true, bondDenom, initialTime.Add(-1*oneYear), initialTime.Add(4*oneYear), rewardsPerSecond),
+		},
+		types.DefaultMultipliers,
+		initialTime.Add(5*oneYear),
+	)
+	suite.keeper.SetParams(suite.ctx, params)
+	suite.keeper.SetPreviousHardDelegatorRewardAccrualTime(suite.ctx, bondDenom, initialTime.Add(-1*blockDuration))
+	suite.keeper.SetHardDelegatorRewardFactor(suite.ctx, bondDenom, sdk.ZeroDec())
+
+	// Reduce the size of the validator set
+	stakingParams := suite.app.GetStakingKeeper().GetParams(suite.ctx)
+	stakingParams.MaxValidators = 2
+	suite.app.GetStakingKeeper().SetParams(suite.ctx, stakingParams)
+
+	// Create 2 validators
+	err := suite.deliverMsgCreateValidator(suite.ctx, suite.validatorAddrs[0], c(bondDenom, 10_000_000))
+	suite.Require().NoError(err)
+	err = suite.deliverMsgCreateValidator(suite.ctx, suite.validatorAddrs[1], c(bondDenom, 10_000_000))
+	suite.Require().NoError(err)
+
+	// End the block so validators become bonded
+	_ = suite.app.EndBlocker(suite.ctx, abci.RequestEndBlock{})
+
+	suite.ctx = suite.ctx.WithBlockTime(initialTime.Add(1 * blockDuration))
+	_ = suite.app.BeginBlocker(suite.ctx, abci.RequestBeginBlock{}) // height and time in header are ignored by module begin blockers
+
+	// Delegate to a bonded validator from the test user. This will initialize their incentive claim.
+	err = suite.deliverMsgDelegate(suite.ctx, suite.addrs[0], suite.validatorAddrs[1], c(bondDenom, 1_000_000))
+	suite.Require().NoError(err)
+
+	// Check that claim has been created with synced reward index but no reward coins
+	initialClaim, found := suite.keeper.GetHardLiquidityProviderClaim(suite.ctx, suite.addrs[0])
+	suite.True(found)
+	initialGlobalIndex, found := suite.keeper.GetHardDelegatorRewardFactor(suite.ctx, bondDenom)
+	suite.True(found)
+	initialClaimIndex, found := initialClaim.DelegatorRewardIndexes.GetRewardIndex(bondDenom)
+	suite.True(found)
+	suite.Require().Equal(initialGlobalIndex, initialClaimIndex.RewardFactor)
+	suite.True(initialClaim.Reward.Empty()) // Initial claim should not have any rewards
+
+	// Start a new block to accumulate some delegation rewards for the user.
+	_ = suite.app.EndBlocker(suite.ctx, abci.RequestEndBlock{})
+	suite.ctx = suite.ctx.WithBlockTime(initialTime.Add(2 * blockDuration))
+	_ = suite.app.BeginBlocker(suite.ctx, abci.RequestBeginBlock{}) // height and time in header are ignored by module begin blockers
+
+	// Fetch validator and slash them
+	stakingKeeper := suite.app.GetStakingKeeper()
+	validator, found := stakingKeeper.GetValidator(suite.ctx, suite.validatorAddrs[1])
+	suite.Require().True(found)
+	suite.Require().True(validator.GetTokens().IsPositive())
+	fraction := sdk.NewDecWithPrec(5, 1)
+	stakingKeeper.Slash(suite.ctx, validator.ConsAddress(), suite.ctx.BlockHeight(), 10, fraction)
+
+	// Check that the user's claim has been synced. ie rewards added, index updated
+	claim, found := suite.keeper.GetHardLiquidityProviderClaim(suite.ctx, suite.addrs[0])
+	suite.Require().True(found)
+	globalIndex, found := suite.keeper.GetHardDelegatorRewardFactor(suite.ctx, bondDenom)
+	suite.Require().True(found)
+	claimIndex, found := claim.DelegatorRewardIndexes.GetRewardIndex(bondDenom)
+	suite.Require().True(found)
+	suite.Require().Equal(globalIndex, claimIndex.RewardFactor)
+
+	// Check that rewards were added
+	suite.Require().Equal(
+		cs(c(rewardsPerSecond.Denom, 58264)),
+		claim.Reward,
+	)
+
+	// Check that reward factor increased from initial value
+	suite.True(claimIndex.RewardFactor.GT(initialClaimIndex.RewardFactor))
+}
+
+// Given a delegation to a bonded validator, when a user redelegates everything to another (bonded) validator, the user's claim is synced
+func (suite *KeeperTestSuite) TestRedelegationSyncsClaim() {
+	suite.SetupWithGenState()
+	initialTime := time.Date(2020, 12, 15, 14, 0, 0, 0, time.UTC)
+	suite.ctx = suite.ctx.WithBlockTime(initialTime)
+	blockDuration := 10 * time.Second
+
+	// Setup incentive state
+	rewardsPerSecond := c("hard", 122354)
+	bondDenom := "ukava"
+	params := types.NewParams(
+		nil,
+		nil,
+		nil,
+		types.RewardPeriods{
+			types.NewRewardPeriod(true, bondDenom, initialTime.Add(-1*oneYear), initialTime.Add(4*oneYear), rewardsPerSecond),
+		},
+		types.DefaultMultipliers,
+		initialTime.Add(5*oneYear),
+	)
+	suite.keeper.SetParams(suite.ctx, params)
+	suite.keeper.SetPreviousHardDelegatorRewardAccrualTime(suite.ctx, bondDenom, initialTime)
+	suite.keeper.SetHardDelegatorRewardFactor(suite.ctx, bondDenom, sdk.ZeroDec())
+
+	// Create 2 validators
+	err := suite.deliverMsgCreateValidator(suite.ctx, suite.validatorAddrs[0], c(bondDenom, 10_000_000))
+	suite.Require().NoError(err)
+	err = suite.deliverMsgCreateValidator(suite.ctx, suite.validatorAddrs[1], c(bondDenom, 5_000_000))
+	suite.Require().NoError(err)
+
+	// Delegatefrom the test user. This will initialize their incentive claim.
+	err = suite.deliverMsgDelegate(suite.ctx, suite.addrs[0], suite.validatorAddrs[0], c(bondDenom, 1_000_000))
+	suite.Require().NoError(err)
+
+	// Start a new block to accumulate some delegation rewards globally.
+	_ = suite.app.EndBlocker(suite.ctx, abci.RequestEndBlock{})
+	suite.ctx = suite.ctx.WithBlockTime(initialTime.Add(1 * blockDuration))
+	_ = suite.app.BeginBlocker(suite.ctx, abci.RequestBeginBlock{}) // height and time in header are ignored by module begin blockers
+
+	// Redelegate the user's delegation between the two validators. This should trigger hooks that sync the user's claim.
+	err = suite.deliverMsgRedelegate(suite.ctx, suite.addrs[0], suite.validatorAddrs[0], suite.validatorAddrs[1], c(bondDenom, 1_000_000))
+	suite.Require().NoError(err)
+
+	// Check that the user's claim has been synced. ie rewards added, index updated
+	claim, found := suite.keeper.GetHardLiquidityProviderClaim(suite.ctx, suite.addrs[0])
+	suite.Require().True(found)
+
+	globalIndex, found := suite.keeper.GetHardDelegatorRewardFactor(suite.ctx, bondDenom)
+	suite.Require().True(found)
+	claimIndex, found := claim.DelegatorRewardIndexes.GetRewardIndex(bondDenom)
+	suite.Require().True(found)
+	suite.Require().Equal(globalIndex, claimIndex.RewardFactor)
+	suite.Require().Equal(
+		cs(c(rewardsPerSecond.Denom, 76471)),
+		claim.Reward,
+	)
+}

x/incentive/types/expected_keepers.go

@@ -19,6 +19,7 @@ type SupplyKeeper interface {
 // StakingKeeper defines the expected staking keeper for module accounts
 type StakingKeeper interface {
 	GetDelegatorDelegations(ctx sdk.Context, delegator sdk.AccAddress, maxRetrieve uint16) (delegations []stakingtypes.Delegation)
+	GetValidatorDelegations(ctx sdk.Context, valAddr sdk.ValAddress) (delegations []stakingtypes.Delegation)
 	GetValidator(ctx sdk.Context, addr sdk.ValAddress) (validator stakingtypes.Validator, found bool)
 	TotalBondedTokens(ctx sdk.Context) sdk.Int
 }