add governors vp invariant

x/gov/keeper/delegation.go

@@ -76,6 +76,22 @@ func (k Keeper) GetGovernorValShares(ctx sdk.Context, governorAddr types.Governo
 	return share, true
 }
 
+// IterateGovernorValShares iterates over all governor validator shares
+func (k Keeper) IterateGovernorValShares(ctx sdk.Context, governorAddr types.GovernorAddress, cb func(index int64, share v1.GovernorValShares) (stop bool)) {
+	store := ctx.KVStore(k.storeKey)
+	iterator := sdk.KVStorePrefixIterator(store, types.ValidatorSharesByGovernorKey(governorAddr, []byte{}))
+	defer iterator.Close()
+
+	for i := int64(0); iterator.Valid(); iterator.Next() {
+		var share v1.GovernorValShares
+		k.cdc.MustUnmarshal(iterator.Value(), &share)
+		if cb(i, share) {
+			break
+		}
+		i++
+	}
+}
+
 // GetGovernorValSharesByValidator gets all governor validator shares for a specific validator
 func (k Keeper) GetGovernorValSharesByValidator(ctx sdk.Context, validatorAddr sdk.ValAddress) []v1.GovernorValShares {
 	store := ctx.KVStore(k.storeKey)
@@ -185,9 +201,9 @@ func (k Keeper) DecreaseGovernorShares(ctx sdk.Context, governorAddr types.Gover
 	k.UpdateGovernorByPowerIndex(ctx, governor)
 }
 
-// UndelegateGovernor decreases all governor validator shares in the store
+// UndelegateFromGovernor decreases all governor validator shares in the store
 // and then removes the governor delegation for the given delegator
-func (k Keeper) undelegateGovernor(ctx sdk.Context, delegatorAddr sdk.AccAddress) {
+func (k Keeper) UndelegateFromGovernor(ctx sdk.Context, delegatorAddr sdk.AccAddress) {
 	delegation, found := k.GetGovernanceDelegation(ctx, delegatorAddr)
 	if !found {
 		return
@@ -217,7 +233,7 @@ func (k Keeper) DelegateToGovernor(ctx sdk.Context, delegatorAddr sdk.AccAddress
 // RedelegateGovernor re-delegates all governor validator shares from one governor to another
 func (k Keeper) RedelegateToGovernor(ctx sdk.Context, delegatorAddr sdk.AccAddress, dstGovernorAddr types.GovernorAddress) {
 	// undelegate from the source governor
-	k.undelegateGovernor(ctx, delegatorAddr)
+	k.UndelegateFromGovernor(ctx, delegatorAddr)
 	// delegate to the destination governor
 	k.DelegateToGovernor(ctx, delegatorAddr, dstGovernorAddr)
 }

x/gov/keeper/invariants.go

@@ -14,6 +14,7 @@ import (
 // RegisterInvariants registers all governance invariants
 func RegisterInvariants(ir sdk.InvariantRegistry, keeper *Keeper, bk types.BankKeeper) {
 	ir.RegisterRoute(types.ModuleName, "module-account", ModuleAccountInvariant(keeper, bk))
+	ir.RegisterRoute(types.ModuleName, "governors-voting-power", GovernorsVotingPowerInvariant(keeper, keeper.sk))
 }
 
 // AllInvariants runs all invariants of the governance module
@@ -47,3 +48,57 @@ func ModuleAccountInvariant(keeper *Keeper, bk types.BankKeeper) sdk.Invariant {
 				balances, expectedDeposits)), broken
 	}
 }
+
+// GovernorsVotingPowerInvariant checks that the voting power of all governors
+// is actually equal to the voting power resulting from the delegated validator shares
+func GovernorsVotingPowerInvariant(keeper *Keeper, sk types.StakingKeeper) sdk.Invariant {
+	return func(ctx sdk.Context) (string, bool) {
+		var (
+			expectedVotingPower sdk.Dec
+			actualVotingPower   sdk.Dec
+			broken              bool
+			brokenGovernorAddr  string
+			fail                bool
+			invariantStr        string
+		)
+
+		keeper.IterateGovernors(ctx, func(index int64, governor v1.GovernorI) bool {
+			expectedVotingPower = governor.GetVotingPower()
+			actualVotingPower = sdk.ZeroDec()
+			fail = false
+			keeper.IterateGovernorValShares(ctx, governor.GetAddress(), func(index int64, shares v1.GovernorValShares) bool {
+				validatorAddr, err := sdk.ValAddressFromBech32(shares.ValidatorAddress)
+				if err != nil {
+					invariantStr = sdk.FormatInvariant(types.ModuleName, "governor %s voting power",
+						fmt.Sprintf("failed to parse validator address %s: %v", shares.ValidatorAddress, err))
+					fail = true
+					return true
+				}
+				validator, found := sk.GetValidator(ctx, validatorAddr)
+				if !found {
+					invariantStr = sdk.FormatInvariant(types.ModuleName, "governor %s voting power",
+						fmt.Sprintf("validator %s not found", validatorAddr.String()))
+					fail = true
+					return true
+				}
+				vp := shares.Shares.MulInt(validator.GetBondedTokens()).Quo(validator.GetDelegatorShares())
+				actualVotingPower = actualVotingPower.Add(vp)
+				return false
+			})
+			broken = !expectedVotingPower.Equal(actualVotingPower)
+			if fail {
+				broken = true
+			}
+			if broken {
+				brokenGovernorAddr = governor.GetAddress().String()
+			}
+			return broken // break on first broken invariant
+		})
+		if !fail {
+			invariantStr = sdk.FormatInvariant(types.ModuleName, "governor %s voting power",
+				fmt.Sprintf("\texpected %s voting power: %s\n\tactual voting power: %s\n",
+					brokenGovernorAddr, expectedVotingPower, actualVotingPower))
+		}
+		return invariantStr, broken
+	}
+}

x/gov/keeper/msg_server.go

@@ -303,7 +303,7 @@ func (k msgServer) UndelegateGovernor(goCtx context.Context, msg *v1.MsgUndelega
 	}
 
 	// Remove the delegation
-	k.undelegateGovernor(ctx, delAddr)
+	k.UndelegateFromGovernor(ctx, delAddr)
 
 	return &v1.MsgUndelegateGovernorResponse{}, nil
 }