fix(upgrade): handle the case of no validator commission (#641)

This PR is to handle the case that the validator has no commission to
withdraw.

issue: #635

Author: 0xHansLee

client/app/upgrades/horace/expected_keepers.go

@@ -0,0 +1,76 @@
+package horace
+
+import (
+	"context"
+	"cosmossdk.io/core/address"
+	sdk "github.com/cosmos/cosmos-sdk/types"
+	dtypes "github.com/cosmos/cosmos-sdk/x/distribution/types"
+	stypes "github.com/cosmos/cosmos-sdk/x/staking/types"
+	minttypes "github.com/piplabs/story/client/x/mint/types"
+)
+
+// StakingKeeper is a test-only interface for upgrade handlers.
+type StakingKeeper interface {
+	GetParams(ctx context.Context) (stypes.Params, error)
+	SetParams(ctx context.Context, params stypes.Params) error
+
+	GetAllValidators(ctx context.Context) ([]stypes.Validator, error)
+	GetValidator(ctx context.Context, valAddr sdk.ValAddress) (stypes.Validator, error)
+	SetValidator(ctx context.Context, val stypes.Validator) error
+
+	GetValidatorDelegations(ctx context.Context, valAddr sdk.ValAddress) ([]stypes.Delegation, error)
+	GetDelegation(ctx context.Context, delAddr sdk.AccAddress, valAddr sdk.ValAddress) (stypes.Delegation, error)
+	SetDelegation(ctx context.Context, del stypes.Delegation) error
+
+	GetPeriodDelegation(
+		ctx context.Context,
+		delAddr sdk.AccAddress,
+		valAddr sdk.ValAddress,
+		periodDelegationID string,
+	) (stypes.PeriodDelegation, error)
+
+	SetPeriodDelegation(
+		ctx context.Context,
+		delAddr sdk.AccAddress,
+		valAddr sdk.ValAddress,
+		pd stypes.PeriodDelegation,
+	) error
+}
+
+// DistributionKeeper is a test-only interface for upgrade handlers.
+type DistributionKeeper interface {
+	WithdrawValidatorCommission(
+		ctx context.Context,
+		valAddr sdk.ValAddress,
+	) (sdk.Coins, error)
+
+	WithdrawDelegationRewards(
+		ctx context.Context,
+		delAddr sdk.AccAddress,
+		valAddr sdk.ValAddress,
+	) (sdk.Coins, error)
+
+	GetDelegatorStartingInfo(
+		ctx context.Context,
+		valAddr sdk.ValAddress,
+		delAddr sdk.AccAddress,
+	) (dtypes.DelegatorStartingInfo, error)
+
+	SetDelegatorStartingInfo(
+		ctx context.Context,
+		valAddr sdk.ValAddress,
+		delAddr sdk.AccAddress,
+		info dtypes.DelegatorStartingInfo,
+	) error
+}
+
+// MintKeeper is a test-only interface for upgrade handlers.
+type MintKeeper interface {
+	GetParams(ctx context.Context) (minttypes.Params, error)
+	SetParams(ctx context.Context, params minttypes.Params) error
+}
+
+// AccountKeeper is a test-only interface for upgrade handlers.
+type AccountKeeper interface {
+	AddressCodec() address.Codec
+}