From 16f10b719f1e488b2f5b7cdf608d1c2a8ef0e2fb Mon Sep 17 00:00:00 2001
From: kogisin <jaybkim2@gmail.com>
Date: Wed, 6 Oct 2021 15:38:46 +0900
Subject: [PATCH 1/6] docs: add comments for flags

---
 x/farming/client/cli/flags.go | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/x/farming/client/cli/flags.go b/x/farming/client/cli/flags.go
index 3d0c11a1..0e008be9 100644
--- a/x/farming/client/cli/flags.go
+++ b/x/farming/client/cli/flags.go
@@ -14,6 +14,7 @@ const (
 	FlagAll              = "all"
 )
 
+// flagSetPlans returns the FlagSet used for farming plan related opertations.
 func flagSetPlans() *flag.FlagSet {
 	fs := flag.NewFlagSet("", flag.ContinueOnError)
 
@@ -25,6 +26,7 @@ func flagSetPlans() *flag.FlagSet {
 	return fs
 }
 
+// flagSetStakings returns the FlagSet used for farmer's staking coin denom.
 func flagSetStakings() *flag.FlagSet {
 	fs := flag.NewFlagSet("", flag.ContinueOnError)
 
@@ -33,6 +35,7 @@ func flagSetStakings() *flag.FlagSet {
 	return fs
 }
 
+// flagSetRewards returns the FlagSet used for farmer's rewards.
 func flagSetRewards() *flag.FlagSet {
 	fs := flag.NewFlagSet("", flag.ContinueOnError)
 
@@ -41,6 +44,7 @@ func flagSetRewards() *flag.FlagSet {
 	return fs
 }
 
+// flagSetHarvest returns the FlagSet used for harvest all staking coin denoms.
 func flagSetHarvest() *flag.FlagSet {
 	fs := flag.NewFlagSet("", flag.ContinueOnError)
 

From 02c12d34374818f1ec2e36215b5df27086700dfc Mon Sep 17 00:00:00 2001
From: kogisin <jaybkim2@gmail.com>
Date: Wed, 6 Oct 2021 20:01:53 +0900
Subject: [PATCH 2/6] docs: update comments

---
 x/farming/client/cli/query.go | 8 +++++++-
 x/farming/client/cli/tx.go    | 8 +++++++-
 x/farming/client/cli/utils.go | 2 ++
 3 files changed, 16 insertions(+), 2 deletions(-)

diff --git a/x/farming/client/cli/query.go b/x/farming/client/cli/query.go
index bce6c783..eb5efa34 100644
--- a/x/farming/client/cli/query.go
+++ b/x/farming/client/cli/query.go
@@ -39,10 +39,10 @@ func GetQueryCmd() *cobra.Command {
 		GetCmdQueryRewards(),
 		GetCmdQueryCurrentEpochDays(),
 	)
-
 	return farmingQueryCmd
 }
 
+// GetCmdQueryParams implements the query params command.
 func GetCmdQueryParams() *cobra.Command {
 	cmd := &cobra.Command{
 		Use:   "params",
@@ -78,6 +78,7 @@ $ %s query %s params
 	return cmd
 }
 
+// GetCmdQueryPlans implements the query all plans command.
 func GetCmdQueryPlans() *cobra.Command {
 	cmd := &cobra.Command{
 		Use:   "plans [optional flags]",
@@ -148,6 +149,7 @@ $ %s query %s plans --staking-coin-denom poolD35A0CC16EE598F90B044CE296A405BA9C3
 	return cmd
 }
 
+// GetCmdQueryPlan implements the query the particular plan command.
 func GetCmdQueryPlan() *cobra.Command {
 	cmd := &cobra.Command{
 		Use:   "plan [plan-id]",
@@ -190,6 +192,7 @@ $ %s query %s plan
 	return cmd
 }
 
+// GetCmdQueryStakings implements the query all stakings command.
 func GetCmdQueryStakings() *cobra.Command {
 	bech32PrefixAccAddr := sdk.GetConfig().GetBech32AccountAddrPrefix()
 
@@ -242,6 +245,7 @@ $ %s query %s stakings %s1gghjut3ccd8ay0zduzj64hwre2fxs9ldmqhffj --staking-coin-
 	return cmd
 }
 
+// GetCmdQueryTotalStakings implements the query total staking amounts for a staking coin denom command.
 func GetCmdQueryTotalStakings() *cobra.Command {
 	cmd := &cobra.Command{
 		Use:   "total-stakings [staking-coin-denom]",
@@ -284,6 +288,7 @@ $ %s query %s total-stakings poolD35A0CC16EE598F90B044CE296A405BA9C381E38837599D
 	return cmd
 }
 
+// GetCmdQueryRewards implements the query all rewards for a farmer command.
 func GetCmdQueryRewards() *cobra.Command {
 	bech32PrefixAccAddr := sdk.GetConfig().GetBech32AccountAddrPrefix()
 
@@ -336,6 +341,7 @@ $ %s query %s rewards %s1gghjut3ccd8ay0zduzj64hwre2fxs9ldmqhffj --staking-coin-d
 	return cmd
 }
 
+// GetCmdQueryCurrentEpochDays implements the query current epoch days command.
 func GetCmdQueryCurrentEpochDays() *cobra.Command {
 	cmd := &cobra.Command{
 		Use:   "current-epoch-days",
diff --git a/x/farming/client/cli/tx.go b/x/farming/client/cli/tx.go
index 31466716..236fb1c1 100644
--- a/x/farming/client/cli/tx.go
+++ b/x/farming/client/cli/tx.go
@@ -46,6 +46,7 @@ func GetTxCmd() *cobra.Command {
 	return farmingTxCmd
 }
 
+// NewCreateFixedAmountPlanCmd implements the create a fixed amount plan command handler.
 func NewCreateFixedAmountPlanCmd() *cobra.Command {
 	cmd := &cobra.Command{
 		Use:   "create-private-fixed-plan [plan-file]",
@@ -118,6 +119,7 @@ Description for the parameters:
 	return cmd
 }
 
+// NewCreateRatioPlanCmd implements the create a ratio plan command handler.
 func NewCreateRatioPlanCmd() *cobra.Command {
 	cmd := &cobra.Command{
 		Use:   "create-private-ratio-plan [plan-file]",
@@ -185,6 +187,7 @@ Description for the parameters:
 	return cmd
 }
 
+// NewStakeCmd implements the stake coin(s) command handler.
 func NewStakeCmd() *cobra.Command {
 	cmd := &cobra.Command{
 		Use:   "stake [amount]",
@@ -225,6 +228,7 @@ $ %s tx %s stake 1000poolD35A0CC16EE598F90B044CE296A405BA9C381E38837599D96F2F70C
 	return cmd
 }
 
+// NewUnstakeCmd implements the unstake coin(s) command handler.
 func NewUnstakeCmd() *cobra.Command {
 	cmd := &cobra.Command{
 		Use:   "unstake [amount]",
@@ -265,6 +269,7 @@ $ %s tx %s unstake 500poolD35A0CC16EE598F90B044CE296A405BA9C381E38837599D96F2F70
 	return cmd
 }
 
+// NewHarvestCmd implements the harvest rewards command handler.
 func NewHarvestCmd() *cobra.Command {
 	cmd := &cobra.Command{
 		Use:   "harvest [staking-coin-denoms]",
@@ -328,6 +333,7 @@ $ %s tx %s harvest --all --from mykey
 	return cmd
 }
 
+// NewAdvanceEpochCmd implements the advance epoch by 1 command handler.
 func NewAdvanceEpochCmd() *cobra.Command {
 	cmd := &cobra.Command{
 		Use:   "advance-epoch",
@@ -352,7 +358,7 @@ func NewAdvanceEpochCmd() *cobra.Command {
 	return cmd
 }
 
-// GetCmdSubmitPublicPlanProposal implements a command handler for submitting a public farming plan transaction to create, update, and delete plan.
+// GetCmdSubmitPublicPlanProposal implements the create/update/delete public farming plan command handler.
 func GetCmdSubmitPublicPlanProposal() *cobra.Command {
 	cmd := &cobra.Command{
 		Use:   "public-farming-plan [proposal-file] [flags]",
diff --git a/x/farming/client/cli/utils.go b/x/farming/client/cli/utils.go
index e87fd81d..f02c998d 100644
--- a/x/farming/client/cli/utils.go
+++ b/x/farming/client/cli/utils.go
@@ -77,6 +77,7 @@ func ParsePublicPlanProposal(cdc codec.JSONCodec, proposalFile string) (types.Pu
 	return proposal, nil
 }
 
+// String returns a human readable string representation of the request.
 func (req PrivateFixedPlanRequest) String() string {
 	result, err := json.Marshal(&req)
 	if err != nil {
@@ -85,6 +86,7 @@ func (req PrivateFixedPlanRequest) String() string {
 	return string(result)
 }
 
+// String returns a human readable string representation of the request.
 func (req PrivateRatioPlanRequest) String() string {
 	result, err := json.Marshal(&req)
 	if err != nil {

From df104f1d61bda97cde020b7fa1ef94540e68d5c6 Mon Sep 17 00:00:00 2001
From: kogisin <jaybkim2@gmail.com>
Date: Wed, 6 Oct 2021 20:08:19 +0900
Subject: [PATCH 3/6] docs: leave proper comments

---
 x/farming/client/proposal_handler.go | 3 ++-
 x/farming/client/rest/rest.go        | 3 ---
 2 files changed, 2 insertions(+), 4 deletions(-)

diff --git a/x/farming/client/proposal_handler.go b/x/farming/client/proposal_handler.go
index a8d00a97..be0880b0 100644
--- a/x/farming/client/proposal_handler.go
+++ b/x/farming/client/proposal_handler.go
@@ -7,7 +7,8 @@ import (
 	"github.com/tendermint/farming/x/farming/client/rest"
 )
 
-// ProposalHandler is the public plan creation handler.
+// ProposalHandler is the public plan command handler.
+// Note that rest.ProposalRESTHandler will be deprecated in the future.
 var (
 	ProposalHandler = govclient.NewProposalHandler(cli.GetCmdSubmitPublicPlanProposal, rest.ProposalRESTHandler)
 )
diff --git a/x/farming/client/rest/rest.go b/x/farming/client/rest/rest.go
index fdf6ddf9..d77eda04 100644
--- a/x/farming/client/rest/rest.go
+++ b/x/farming/client/rest/rest.go
@@ -7,9 +7,6 @@ import (
 	govrest "github.com/cosmos/cosmos-sdk/x/gov/client/rest"
 )
 
-// TODO: not implemented yet;
-// although this legacy REST API may not be needed, it needs for ProposalHandler; otherwise it throws panic when starting the chain
-
 // ProposalRESTHandler returns a ProposalRESTHandler that exposes the farming plan proposal (add/update/delete) REST handler with a given sub-route.
 func ProposalRESTHandler(clientCtx client.Context) govrest.ProposalRESTHandler {
 	return govrest.ProposalRESTHandler{

From e8c39f16f9c31482250a1a4b3dad089376d210d5 Mon Sep 17 00:00:00 2001
From: Hanjun Kim <hallazzang@gmail.com>
Date: Fri, 8 Oct 2021 18:22:35 +0900
Subject: [PATCH 4/6] chore: update comments for keeper

---
 x/farming/keeper/epoch.go            | 18 ++++++---
 x/farming/keeper/epoch_test.go       |  9 ++---
 x/farming/keeper/grpc_query.go       | 11 ++++--
 x/farming/keeper/keeper.go           | 13 ++++---
 x/farming/keeper/plan.go             | 20 +++++-----
 x/farming/keeper/proposal_handler.go |  2 +-
 x/farming/keeper/reward.go           | 58 +++++++++++++++++++++++++++-
 x/farming/keeper/staking.go          | 57 +++++++++++++++++++++------
 x/farming/keeper/staking_test.go     |  6 +--
 9 files changed, 147 insertions(+), 47 deletions(-)

diff --git a/x/farming/keeper/epoch.go b/x/farming/keeper/epoch.go
index 49e2313b..f7e212ff 100644
--- a/x/farming/keeper/epoch.go
+++ b/x/farming/keeper/epoch.go
@@ -10,21 +10,25 @@ import (
 	"github.com/tendermint/farming/x/farming/types"
 )
 
-func (k Keeper) GetLastEpochTime(ctx sdk.Context) (time.Time, bool) {
+// GetLastEpochTime returns the last time the epoch ended.
+func (k Keeper) GetLastEpochTime(ctx sdk.Context) (t time.Time, found bool) {
 	store := ctx.KVStore(k.storeKey)
 	bz := store.Get(types.LastEpochTimeKey)
 	if bz == nil {
-		return time.Time{}, false
+		return
 	}
 	var ts gogotypes.Timestamp
 	k.cdc.MustUnmarshal(bz, &ts)
-	t, err := gogotypes.TimestampFromProto(&ts)
+	var err error
+	t, err = gogotypes.TimestampFromProto(&ts)
 	if err != nil {
 		panic(err)
 	}
-	return t, true
+	found = true
+	return
 }
 
+// SetLastEpochTime sets the last time the epoch ended.
 func (k Keeper) SetLastEpochTime(ctx sdk.Context, t time.Time) {
 	store := ctx.KVStore(k.storeKey)
 	ts, err := gogotypes.TimestampProto(t)
@@ -35,6 +39,8 @@ func (k Keeper) SetLastEpochTime(ctx sdk.Context, t time.Time) {
 	store.Set(types.LastEpochTimeKey, bz)
 }
 
+// AdvanceEpoch ends the current epoch. When an epoch ends, rewards
+// are distributed and queued staking coins become staked.
 func (k Keeper) AdvanceEpoch(ctx sdk.Context) error {
 	if err := k.AllocateRewards(ctx); err != nil {
 		return err
@@ -45,7 +51,7 @@ func (k Keeper) AdvanceEpoch(ctx sdk.Context) error {
 	return nil
 }
 
-// GetCurrentEpochDays returns the  current epoch days.
+// GetCurrentEpochDays returns the current epoch days(period).
 func (k Keeper) GetCurrentEpochDays(ctx sdk.Context) uint32 {
 	var epochDays uint32
 	store := ctx.KVStore(k.storeKey)
@@ -63,7 +69,7 @@ func (k Keeper) GetCurrentEpochDays(ctx sdk.Context) uint32 {
 	return epochDays
 }
 
-// SetCurrentEpochDays sets the  current epoch days.
+// SetCurrentEpochDays sets the current epoch days(period).
 func (k Keeper) SetCurrentEpochDays(ctx sdk.Context, epochDays uint32) {
 	store := ctx.KVStore(k.storeKey)
 	bz := k.cdc.MustMarshal(&gogotypes.UInt32Value{Value: epochDays})
diff --git a/x/farming/keeper/epoch_test.go b/x/farming/keeper/epoch_test.go
index dcc87e65..91be4b60 100644
--- a/x/farming/keeper/epoch_test.go
+++ b/x/farming/keeper/epoch_test.go
@@ -24,12 +24,11 @@ func (suite *KeeperTestSuite) TestLastEpochTime() {
 
 func (suite *KeeperTestSuite) TestFirstEpoch() {
 	// The first epoch may run very quickly depending on when
-	// the farming module is deployed,
+	// the farming module was activated,
 	// meaning that (block time) - (last epoch time) may be smaller
-	// than epoch_days parameter on the first epoch.
+	// than the current epoch_days for the first epoch.
 
-	params := suite.keeper.GetParams(suite.ctx)
-	suite.Require().Equal(uint32(1), params.NextEpochDays)
+	suite.Require().Equal(uint32(1), suite.keeper.GetCurrentEpochDays(suite.ctx))
 
 	suite.ctx = suite.ctx.WithBlockTime(types.ParseTime("2021-08-11T23:59:59Z"))
 	farming.EndBlocker(suite.ctx, suite.keeper)
@@ -39,7 +38,7 @@ func (suite *KeeperTestSuite) TestFirstEpoch() {
 	suite.ctx = suite.ctx.WithBlockTime(types.ParseTime("2021-08-12T00:00:00Z"))
 	farming.EndBlocker(suite.ctx, suite.keeper)
 	t, _ := suite.keeper.GetLastEpochTime(suite.ctx)
-	suite.Require().True(t.After(lastEpochTime)) // Indicating that the epoch advanced.
+	suite.Require().True(t.After(lastEpochTime)) // Indicating that the epoch ended.
 }
 
 func (suite *KeeperTestSuite) TestEpochDays() {
diff --git a/x/farming/keeper/grpc_query.go b/x/farming/keeper/grpc_query.go
index 1cec3fe4..ebbbc4a1 100644
--- a/x/farming/keeper/grpc_query.go
+++ b/x/farming/keeper/grpc_query.go
@@ -77,7 +77,7 @@ func (k Querier) Plans(c context.Context, req *types.QueryPlansRequest) (*types.
 		if err != nil {
 			return false, err
 		}
-		any, err := codectypes.NewAnyWithValue(plan)
+		planAny, err := types.PackPlan(plan)
 		if err != nil {
 			return false, err
 		}
@@ -114,7 +114,7 @@ func (k Querier) Plans(c context.Context, req *types.QueryPlansRequest) (*types.
 		}
 
 		if accumulate {
-			plans = append(plans, any)
+			plans = append(plans, planAny)
 		}
 
 		return true, nil
@@ -138,14 +138,15 @@ func (k Querier) Plan(c context.Context, req *types.QueryPlanRequest) (*types.Qu
 		return nil, status.Errorf(codes.NotFound, "plan %d not found", req.PlanId)
 	}
 
-	any, err := codectypes.NewAnyWithValue(plan)
+	planAny, err := types.PackPlan(plan)
 	if err != nil {
 		return nil, status.Error(codes.Internal, err.Error())
 	}
 
-	return &types.QueryPlanResponse{Plan: any}, nil
+	return &types.QueryPlanResponse{Plan: planAny}, nil
 }
 
+// Stakings queries stakings for a farmer.
 func (k Querier) Stakings(c context.Context, req *types.QueryStakingsRequest) (*types.QueryStakingsResponse, error) {
 	if req == nil {
 		return nil, status.Error(codes.InvalidArgument, "empty request")
@@ -191,6 +192,7 @@ func (k Querier) Stakings(c context.Context, req *types.QueryStakingsRequest) (*
 	return resp, nil
 }
 
+// TotalStakings queries total staking coin amount for a specific staking coin denom.
 func (k Querier) TotalStakings(c context.Context, req *types.QueryTotalStakingsRequest) (*types.QueryTotalStakingsResponse, error) {
 	if req == nil {
 		return nil, status.Error(codes.InvalidArgument, "empty request")
@@ -212,6 +214,7 @@ func (k Querier) TotalStakings(c context.Context, req *types.QueryTotalStakingsR
 	}, nil
 }
 
+// Rewards queries accumulated rewards for a farmer.
 func (k Querier) Rewards(c context.Context, req *types.QueryRewardsRequest) (*types.QueryRewardsResponse, error) {
 	if req == nil {
 		return nil, status.Error(codes.InvalidArgument, "empty request")
diff --git a/x/farming/keeper/keeper.go b/x/farming/keeper/keeper.go
index 9482d39b..2e105e75 100644
--- a/x/farming/keeper/keeper.go
+++ b/x/farming/keeper/keeper.go
@@ -14,7 +14,10 @@ import (
 )
 
 var (
-	enableAdvanceEpoch = "false" // set it to "true" using build flags to enable AdvanceEpoch msg handling.
+	enableAdvanceEpoch = "false" // Set this to "true" using build flags to enable AdvanceEpoch msg handling.
+
+	// EnableAdvanceEpoch indicates whether msgServer accepts MsgAdvanceEpoch or not.
+	// Never set this to true in production mode. Doing that will expose serious attack vector.
 	EnableAdvanceEpoch = false
 )
 
@@ -71,7 +74,7 @@ func (k Keeper) Logger(ctx sdk.Context) log.Logger {
 	return ctx.Logger().With("module", "x/"+types.ModuleName)
 }
 
-// GetParams gets the parameters for the farming module.
+// GetParams returns the parameters for the farming module.
 func (k Keeper) GetParams(ctx sdk.Context) (params types.Params) {
 	k.paramSpace.GetParamSet(ctx, &params)
 	return params
@@ -82,15 +85,15 @@ func (k Keeper) SetParams(ctx sdk.Context, params types.Params) {
 	k.paramSpace.SetParamSet(ctx, &params)
 }
 
-// GetCodec return codec.Codec object used by the keeper
+// GetCodec returns codec.Codec object used by the keeper>
 func (k Keeper) GetCodec() codec.BinaryCodec { return k.cdc }
 
-// GetStakingReservePoolAcc returns module account for Staking Reserve Pool account
+// GetStakingReservePoolAcc returns module account for the staking reserve pool account.
 func (k Keeper) GetStakingReservePoolAcc(ctx sdk.Context) sdk.AccAddress { // nolint:interfacer
 	return types.StakingReserveAcc
 }
 
-// GetRewardsReservePoolAcc returns temporary module account for Reward coins Reserve Pool account
+// GetRewardsReservePoolAcc returns module account for the rewards reserve pool account.
 func (k Keeper) GetRewardsReservePoolAcc(ctx sdk.Context) sdk.AccAddress { // nolint:interfacer
 	return types.RewardsReserveAcc
 }
diff --git a/x/farming/keeper/plan.go b/x/farming/keeper/plan.go
index 4897f0bf..12e98668 100644
--- a/x/farming/keeper/plan.go
+++ b/x/farming/keeper/plan.go
@@ -11,7 +11,7 @@ import (
 	"github.com/tendermint/farming/x/farming/types"
 )
 
-// NewPlan sets the next plan number to a given plan interface
+// NewPlan sets the next plan number to a given PlanI.
 func (k Keeper) NewPlan(ctx sdk.Context, plan types.PlanI) types.PlanI {
 	if err := plan.SetId(k.GetNextPlanIdWithUpdate(ctx)); err != nil {
 		panic(err)
@@ -20,7 +20,7 @@ func (k Keeper) NewPlan(ctx sdk.Context, plan types.PlanI) types.PlanI {
 	return plan
 }
 
-// GetPlan implements PlanI.
+// GetPlan returns a plan for a given plan id.
 func (k Keeper) GetPlan(ctx sdk.Context, id uint64) (plan types.PlanI, found bool) {
 	store := ctx.KVStore(k.storeKey)
 	bz := store.Get(types.GetPlanKey(id))
@@ -31,7 +31,7 @@ func (k Keeper) GetPlan(ctx sdk.Context, id uint64) (plan types.PlanI, found boo
 	return k.decodePlan(bz), true
 }
 
-// GetPlans returns all plans in the Keeper.
+// GetPlans returns all plans in the store.
 func (k Keeper) GetPlans(ctx sdk.Context) (plans []types.PlanI) {
 	k.IteratePlans(ctx, func(plan types.PlanI) (stop bool) {
 		plans = append(plans, plan)
@@ -41,7 +41,7 @@ func (k Keeper) GetPlans(ctx sdk.Context) (plans []types.PlanI) {
 	return plans
 }
 
-// SetPlan implements PlanI.
+// SetPlan sets a plan for a given plan id.
 func (k Keeper) SetPlan(ctx sdk.Context, plan types.PlanI) {
 	id := plan.GetId()
 	store := ctx.KVStore(k.storeKey)
@@ -54,7 +54,7 @@ func (k Keeper) SetPlan(ctx sdk.Context, plan types.PlanI) {
 	store.Set(types.GetPlanKey(id), bz)
 }
 
-// RemovePlan removes an plan for the plan mapper store.
+// RemovePlan removes a plan from the store.
 // NOTE: this will cause supply invariant violation if called
 func (k Keeper) RemovePlan(ctx sdk.Context, plan types.PlanI) {
 	id := plan.GetId()
@@ -86,7 +86,7 @@ func (k Keeper) GetNextPlanIdWithUpdate(ctx sdk.Context) uint64 {
 	return id
 }
 
-// SetGlobalPlanId set the global Plan ID counter.
+// SetGlobalPlanId sets the global Plan ID counter.
 func (k Keeper) SetGlobalPlanId(ctx sdk.Context, id uint64) {
 	store := ctx.KVStore(k.storeKey)
 	bz := k.cdc.MustMarshal(&gogotypes.UInt64Value{Value: id})
@@ -124,13 +124,13 @@ func (k Keeper) decodePlan(bz []byte) types.PlanI {
 	return acc
 }
 
-// MarshalPlan protobuf serializes an Plan interface
+// MarshalPlan serializes a plan.
 func (k Keeper) MarshalPlan(plan types.PlanI) ([]byte, error) { // nolint:interfacer
 	return k.cdc.MarshalInterface(plan)
 }
 
-// UnmarshalPlan returns an Plan interface from raw encoded plan
-// bytes of a Proto-based Plan type
+// UnmarshalPlan returns a plan from raw serialized
+// bytes of a Proto-based Plan type.
 func (k Keeper) UnmarshalPlan(bz []byte) (plan types.PlanI, err error) {
 	return plan, k.cdc.UnmarshalInterface(bz, &plan)
 }
@@ -265,6 +265,8 @@ func (k Keeper) TerminatePlan(ctx sdk.Context, plan types.PlanI) error {
 	return nil
 }
 
+// GeneratePrivatePlanFarmingPoolAddress returns a unique account address
+// of a farming pool for a private plan.
 func (k Keeper) GeneratePrivatePlanFarmingPoolAddress(ctx sdk.Context, name string) (sdk.AccAddress, error) {
 	nextPlanId := k.GetGlobalPlanId(ctx) + 1
 	poolAcc := types.PrivatePlanFarmingPoolAddress(name, nextPlanId)
diff --git a/x/farming/keeper/proposal_handler.go b/x/farming/keeper/proposal_handler.go
index c84fe8b0..a3da501f 100644
--- a/x/farming/keeper/proposal_handler.go
+++ b/x/farming/keeper/proposal_handler.go
@@ -217,7 +217,7 @@ func (k Keeper) UpdatePublicPlanProposal(ctx sdk.Context, proposals []*types.Upd
 	return nil
 }
 
-// DeletePublicPlanProposal delets public plan proposal once the governance proposal is passed.
+// DeletePublicPlanProposal deletes public plan proposal once the governance proposal is passed.
 func (k Keeper) DeletePublicPlanProposal(ctx sdk.Context, proposals []*types.DeleteRequestProposal) error {
 	for _, p := range proposals {
 		plan, found := k.GetPlan(ctx, p.GetPlanId())
diff --git a/x/farming/keeper/reward.go b/x/farming/keeper/reward.go
index ea0bc077..cbbe54d6 100644
--- a/x/farming/keeper/reward.go
+++ b/x/farming/keeper/reward.go
@@ -9,6 +9,8 @@ import (
 	"github.com/tendermint/farming/x/farming/types"
 )
 
+// GetHistoricalRewards returns historical rewards for a given
+// staking coin denom and an epoch number.
 func (k Keeper) GetHistoricalRewards(ctx sdk.Context, stakingCoinDenom string, epoch uint64) (rewards types.HistoricalRewards, found bool) {
 	store := ctx.KVStore(k.storeKey)
 	bz := store.Get(types.GetHistoricalRewardsKey(stakingCoinDenom, epoch))
@@ -20,17 +22,24 @@ func (k Keeper) GetHistoricalRewards(ctx sdk.Context, stakingCoinDenom string, e
 	return
 }
 
+// SetHistoricalRewards sets historical rewards for a given
+// staking coin denom and an epoch number.
 func (k Keeper) SetHistoricalRewards(ctx sdk.Context, stakingCoinDenom string, epoch uint64, rewards types.HistoricalRewards) {
 	store := ctx.KVStore(k.storeKey)
 	bz := k.cdc.MustMarshal(&rewards)
 	store.Set(types.GetHistoricalRewardsKey(stakingCoinDenom, epoch), bz)
 }
 
+// DeleteHistoricalRewards deletes historical rewards for a given
+// staking coin denom and an epoch number.
 func (k Keeper) DeleteHistoricalRewards(ctx sdk.Context, stakingCoinDenom string, epoch uint64) {
 	store := ctx.KVStore(k.storeKey)
 	store.Delete(types.GetHistoricalRewardsKey(stakingCoinDenom, epoch))
 }
 
+// IterateHistoricalRewards iterates through all historical rewards
+// stored in the store and invokes callback function for each item.
+// Stops the iteration when the callback function returns true.
 func (k Keeper) IterateHistoricalRewards(ctx sdk.Context, cb func(stakingCoinDenom string, epoch uint64, rewards types.HistoricalRewards) (stop bool)) {
 	store := ctx.KVStore(k.storeKey)
 	iter := sdk.KVStorePrefixIterator(store, types.HistoricalRewardsKeyPrefix)
@@ -45,6 +54,8 @@ func (k Keeper) IterateHistoricalRewards(ctx sdk.Context, cb func(stakingCoinDen
 	}
 }
 
+// GetCurrentEpoch returns the current epoch number for a given
+// staking coin denom.
 func (k Keeper) GetCurrentEpoch(ctx sdk.Context, stakingCoinDenom string) uint64 {
 	store := ctx.KVStore(k.storeKey)
 	bz := store.Get(types.GetCurrentEpochKey(stakingCoinDenom))
@@ -53,6 +64,8 @@ func (k Keeper) GetCurrentEpoch(ctx sdk.Context, stakingCoinDenom string) uint64
 	return val.GetValue()
 }
 
+// SetCurrentEpoch sets the current epoch number for a given
+// staking coin denom.
 func (k Keeper) SetCurrentEpoch(ctx sdk.Context, stakingCoinDenom string, currentEpoch uint64) {
 	store := ctx.KVStore(k.storeKey)
 	val := gogotypes.UInt64Value{Value: currentEpoch}
@@ -60,6 +73,9 @@ func (k Keeper) SetCurrentEpoch(ctx sdk.Context, stakingCoinDenom string, curren
 	store.Set(types.GetCurrentEpochKey(stakingCoinDenom), bz)
 }
 
+// IterateCurrentEpochs iterates through all current epoch infos
+// stored in the store and invokes callback function for each item.
+// Stops the iteration when the callback function returns true.
 func (k Keeper) IterateCurrentEpochs(ctx sdk.Context, cb func(stakingCoinDenom string, currentEpoch uint64) (stop bool)) {
 	store := ctx.KVStore(k.storeKey)
 	iter := sdk.KVStorePrefixIterator(store, types.CurrentEpochKeyPrefix)
@@ -74,6 +90,8 @@ func (k Keeper) IterateCurrentEpochs(ctx sdk.Context, cb func(stakingCoinDenom s
 	}
 }
 
+// GetOutstandingRewards returns outstanding rewards for a given
+// staking coin denom.
 func (k Keeper) GetOutstandingRewards(ctx sdk.Context, stakingCoinDenom string) (rewards types.OutstandingRewards, found bool) {
 	store := ctx.KVStore(k.storeKey)
 	bz := store.Get(types.GetOutstandingRewardsKey(stakingCoinDenom))
@@ -85,17 +103,24 @@ func (k Keeper) GetOutstandingRewards(ctx sdk.Context, stakingCoinDenom string)
 	return
 }
 
+// SetOutstandingRewards sets outstanding rewards for a given
+// staking coin denom.
 func (k Keeper) SetOutstandingRewards(ctx sdk.Context, stakingCoinDenom string, rewards types.OutstandingRewards) {
 	store := ctx.KVStore(k.storeKey)
 	bz := k.cdc.MustMarshal(&rewards)
 	store.Set(types.GetOutstandingRewardsKey(stakingCoinDenom), bz)
 }
 
+// DeleteOutstandingRewards deletes outstanding rewards for a given
+// staking coin denom.
 func (k Keeper) DeleteOutstandingRewards(ctx sdk.Context, stakingCoinDenom string) {
 	store := ctx.KVStore(k.storeKey)
 	store.Delete(types.GetOutstandingRewardsKey(stakingCoinDenom))
 }
 
+// IterateOutstandingRewards iterates through all outstanding rewards
+// stored in the store and invokes callback function for each item.
+// Stops the iteration when the callback function returns true.
 func (k Keeper) IterateOutstandingRewards(ctx sdk.Context, cb func(stakingCoinDenom string, rewards types.OutstandingRewards) (stop bool)) {
 	store := ctx.KVStore(k.storeKey)
 	iter := sdk.KVStorePrefixIterator(store, types.OutstandingRewardsKeyPrefix)
@@ -110,12 +135,18 @@ func (k Keeper) IterateOutstandingRewards(ctx sdk.Context, cb func(stakingCoinDe
 	}
 }
 
+// IncreaseOutstandingRewards increases outstanding rewards for a given
+// staking coin denom by given amount.
 func (k Keeper) IncreaseOutstandingRewards(ctx sdk.Context, stakingCoinDenom string, amount sdk.DecCoins) {
 	outstanding, _ := k.GetOutstandingRewards(ctx, stakingCoinDenom)
 	outstanding.Rewards = outstanding.Rewards.Add(amount...)
 	k.SetOutstandingRewards(ctx, stakingCoinDenom, outstanding)
 }
 
+// DecreaseOutstandingRewards decreases outstanding rewards for a given
+// staking coin denom by given amount.
+// If the resulting outstanding rewards is zero, then the outstanding rewards
+// will be deleted, not updated.
 func (k Keeper) DecreaseOutstandingRewards(ctx sdk.Context, stakingCoinDenom string, amount sdk.DecCoins) {
 	outstanding, found := k.GetOutstandingRewards(ctx, stakingCoinDenom)
 	if !found {
@@ -129,6 +160,8 @@ func (k Keeper) DecreaseOutstandingRewards(ctx sdk.Context, stakingCoinDenom str
 	}
 }
 
+// CalculateRewards returns rewards accumulated until endingEpoch
+// for a farmer for a given staking coin denom.
 func (k Keeper) CalculateRewards(ctx sdk.Context, farmerAcc sdk.AccAddress, stakingCoinDenom string, endingEpoch uint64) (rewards sdk.DecCoins) {
 	staking, found := k.GetStaking(ctx, stakingCoinDenom, farmerAcc)
 	if !found {
@@ -142,6 +175,8 @@ func (k Keeper) CalculateRewards(ctx sdk.Context, farmerAcc sdk.AccAddress, stak
 	return
 }
 
+// Rewards returns truncated rewards accumulated until the current epoch
+// for a farmer for a given staking coin denom.
 func (k Keeper) Rewards(ctx sdk.Context, farmerAcc sdk.AccAddress, stakingCoinDenom string) sdk.Coins {
 	currentEpoch := k.GetCurrentEpoch(ctx, stakingCoinDenom)
 	rewards := k.CalculateRewards(ctx, farmerAcc, stakingCoinDenom, currentEpoch-1)
@@ -150,6 +185,8 @@ func (k Keeper) Rewards(ctx sdk.Context, farmerAcc sdk.AccAddress, stakingCoinDe
 	return truncatedRewards
 }
 
+// AllRewards returns truncated total rewards accumulated until the
+// current epoch for a farmer.
 func (k Keeper) AllRewards(ctx sdk.Context, farmerAcc sdk.AccAddress) sdk.Coins {
 	totalRewards := sdk.NewCoins()
 	k.IterateStakingsByFarmer(ctx, farmerAcc, func(stakingCoinDenom string, staking types.Staking) (stop bool) {
@@ -160,6 +197,10 @@ func (k Keeper) AllRewards(ctx sdk.Context, farmerAcc sdk.AccAddress) sdk.Coins
 	return totalRewards
 }
 
+// WithdrawRewards withdraws accumulated rewards for a farmer for a given
+// staking coin denom.
+// It decreases outstanding rewards and set the starting epoch of a
+// staking.
 func (k Keeper) WithdrawRewards(ctx sdk.Context, farmerAcc sdk.AccAddress, stakingCoinDenom string) (sdk.Coins, error) {
 	staking, found := k.GetStaking(ctx, stakingCoinDenom, farmerAcc)
 	if !found {
@@ -187,6 +228,7 @@ func (k Keeper) WithdrawRewards(ctx sdk.Context, farmerAcc sdk.AccAddress, staki
 	return truncatedRewards, nil
 }
 
+// WithdrawAllRewards withdraws all accumulated rewards for a farmer.
 func (k Keeper) WithdrawAllRewards(ctx sdk.Context, farmerAcc sdk.AccAddress) (sdk.Coins, error) {
 	totalRewards := sdk.NewCoins()
 	k.IterateStakingsByFarmer(ctx, farmerAcc, func(stakingCoinDenom string, staking types.Staking) (stop bool) {
@@ -237,11 +279,16 @@ func (k Keeper) Harvest(ctx sdk.Context, farmerAcc sdk.AccAddress, stakingCoinDe
 	return nil
 }
 
+// AllocationInfo holds information about an allocation for a plan.
 type AllocationInfo struct {
 	Plan   types.PlanI
 	Amount sdk.Coins
 }
 
+// AllocationInfos returns allocation infos for the end
+// of the current epoch.
+// When total allocated coins for a farming pool exceeds the pool's
+// balance, then allocation will not happen.
 func (k Keeper) AllocationInfos(ctx sdk.Context) []AllocationInfo {
 	farmingPoolBalances := make(map[string]sdk.Coins)   // farmingPoolAddress => sdk.Coins
 	allocCoins := make(map[string]map[uint64]sdk.Coins) // farmingPoolAddress => (planId => sdk.Coins)
@@ -301,6 +348,8 @@ func (k Keeper) AllocationInfos(ctx sdk.Context) []AllocationInfo {
 	return allocInfos
 }
 
+// AllocateRewards updates historical rewards and current epoch info
+// based on the allocation infos.
 func (k Keeper) AllocateRewards(ctx sdk.Context) error {
 	unitRewardsByDenom := map[string]sdk.DecCoins{} // (staking coin denom) => (unit rewards)
 
@@ -366,7 +415,9 @@ func (k Keeper) AllocateRewards(ctx sdk.Context) error {
 	return nil
 }
 
-// ValidateRemainingRewardsAmount checks that the balance of the RewardPoolAddresses of all plans greater than the total amount of unwithdrawn reward coins in all reward objects
+// ValidateRemainingRewardsAmount checks that the balance of the
+// rewards reserve pool is greater than the total amount of
+// unwithdrawn rewards.
 // TODO: correct comment above
 func (k Keeper) ValidateRemainingRewardsAmount(ctx sdk.Context) error {
 	remainingRewards := sdk.NewCoins()
@@ -384,6 +435,9 @@ func (k Keeper) ValidateRemainingRewardsAmount(ctx sdk.Context) error {
 	return nil
 }
 
+// ValidateOutstandingRewards checks that the balance of the
+// rewards reserve pool is greater than the total amount of
+// outstanding rewards.
 func (k Keeper) ValidateOutstandingRewards(ctx sdk.Context) error {
 	totalOutstandingRewards := sdk.NewDecCoins()
 	k.IterateOutstandingRewards(ctx, func(stakingCoinDenom string, rewards types.OutstandingRewards) (stop bool) {
@@ -394,7 +448,7 @@ func (k Keeper) ValidateOutstandingRewards(ctx sdk.Context) error {
 	rewardsReservePoolBalances := sdk.NewDecCoinsFromCoins(k.bankKeeper.GetAllBalances(ctx, k.GetRewardsReservePoolAcc(ctx))...)
 	_, hasNeg := rewardsReservePoolBalances.SafeSub(totalOutstandingRewards)
 	if hasNeg {
-		return types.ErrInvalidStakingReservedAmount // TODO: use different error type
+		return types.ErrInvalidRemainingRewardsAmount // TODO: use different error type
 	}
 
 	return nil
diff --git a/x/farming/keeper/staking.go b/x/farming/keeper/staking.go
index 3533e23e..8c293529 100644
--- a/x/farming/keeper/staking.go
+++ b/x/farming/keeper/staking.go
@@ -7,7 +7,7 @@ import (
 	"github.com/tendermint/farming/x/farming/types"
 )
 
-// GetStaking returns a specific staking identified by id.
+// GetStaking returns a staking for given staking denom and farmer.
 func (k Keeper) GetStaking(ctx sdk.Context, stakingCoinDenom string, farmerAcc sdk.AccAddress) (staking types.Staking, found bool) {
 	store := ctx.KVStore(k.storeKey)
 	bz := store.Get(types.GetStakingKey(stakingCoinDenom, farmerAcc))
@@ -19,7 +19,7 @@ func (k Keeper) GetStaking(ctx sdk.Context, stakingCoinDenom string, farmerAcc s
 	return
 }
 
-// SetStaking implements Staking.
+// SetStaking sets a staking for given staking coin denom and farmer.
 func (k Keeper) SetStaking(ctx sdk.Context, stakingCoinDenom string, farmerAcc sdk.AccAddress, staking types.Staking) {
 	store := ctx.KVStore(k.storeKey)
 	bz := k.cdc.MustMarshal(&staking)
@@ -27,12 +27,16 @@ func (k Keeper) SetStaking(ctx sdk.Context, stakingCoinDenom string, farmerAcc s
 	store.Set(types.GetStakingIndexKey(farmerAcc, stakingCoinDenom), []byte{})
 }
 
+// DeleteStaking deletes a staking for given staking coin denom and farmer.
 func (k Keeper) DeleteStaking(ctx sdk.Context, stakingCoinDenom string, farmerAcc sdk.AccAddress) {
 	store := ctx.KVStore(k.storeKey)
 	store.Delete(types.GetStakingKey(stakingCoinDenom, farmerAcc))
 	store.Delete(types.GetStakingIndexKey(farmerAcc, stakingCoinDenom))
 }
 
+// IterateStakings iterates through all stakings stored in the store
+// and invokes callback function for each item.
+// Stops the iteration when the callback function returns true.
 func (k Keeper) IterateStakings(ctx sdk.Context, cb func(stakingCoinDenom string, farmerAcc sdk.AccAddress, staking types.Staking) (stop bool)) {
 	store := ctx.KVStore(k.storeKey)
 	iter := sdk.KVStorePrefixIterator(store, types.StakingKeyPrefix)
@@ -47,6 +51,9 @@ func (k Keeper) IterateStakings(ctx sdk.Context, cb func(stakingCoinDenom string
 	}
 }
 
+// IterateStakingsByFarmer iterates through all stakings by a farmer
+// stored in the store and invokes callback function for each item.
+// Stops the iteration when the callback function returns true.
 func (k Keeper) IterateStakingsByFarmer(ctx sdk.Context, farmerAcc sdk.AccAddress, cb func(stakingCoinDenom string, staking types.Staking) (stop bool)) {
 	store := ctx.KVStore(k.storeKey)
 	iter := sdk.KVStorePrefixIterator(store, types.GetStakingsByFarmerPrefix(farmerAcc))
@@ -60,6 +67,7 @@ func (k Keeper) IterateStakingsByFarmer(ctx sdk.Context, farmerAcc sdk.AccAddres
 	}
 }
 
+// GetAllStakedCoinsByFarmer returns all coins that are staked by a farmer.
 func (k Keeper) GetAllStakedCoinsByFarmer(ctx sdk.Context, farmerAcc sdk.AccAddress) sdk.Coins {
 	stakedCoins := sdk.NewCoins()
 	k.IterateStakingsByFarmer(ctx, farmerAcc, func(stakingCoinDenom string, staking types.Staking) (stop bool) {
@@ -69,6 +77,8 @@ func (k Keeper) GetAllStakedCoinsByFarmer(ctx sdk.Context, farmerAcc sdk.AccAddr
 	return stakedCoins
 }
 
+// GetQueuedStaking returns a queued staking for given staking coin denom
+// and farmer.
 func (k Keeper) GetQueuedStaking(ctx sdk.Context, stakingCoinDenom string, farmerAcc sdk.AccAddress) (queuedStaking types.QueuedStaking, found bool) {
 	store := ctx.KVStore(k.storeKey)
 	bz := store.Get(types.GetQueuedStakingKey(stakingCoinDenom, farmerAcc))
@@ -80,15 +90,8 @@ func (k Keeper) GetQueuedStaking(ctx sdk.Context, stakingCoinDenom string, farme
 	return
 }
 
-func (k Keeper) GetAllQueuedStakedCoinsByFarmer(ctx sdk.Context, farmerAcc sdk.AccAddress) sdk.Coins {
-	stakedCoins := sdk.NewCoins()
-	k.IterateQueuedStakingsByFarmer(ctx, farmerAcc, func(stakingCoinDenom string, queuedStaking types.QueuedStaking) (stop bool) {
-		stakedCoins = stakedCoins.Add(sdk.NewCoin(stakingCoinDenom, queuedStaking.Amount))
-		return false
-	})
-	return stakedCoins
-}
-
+// SetQueuedStaking sets a queued staking for given staking coin denom
+// and farmer.
 func (k Keeper) SetQueuedStaking(ctx sdk.Context, stakingCoinDenom string, farmerAcc sdk.AccAddress, queuedStaking types.QueuedStaking) {
 	store := ctx.KVStore(k.storeKey)
 	bz := k.cdc.MustMarshal(&queuedStaking)
@@ -96,12 +99,17 @@ func (k Keeper) SetQueuedStaking(ctx sdk.Context, stakingCoinDenom string, farme
 	store.Set(types.GetQueuedStakingIndexKey(farmerAcc, stakingCoinDenom), []byte{})
 }
 
+// DeleteQueuedStaking deletes a queued staking for given staking coin denom
+// and farmer.
 func (k Keeper) DeleteQueuedStaking(ctx sdk.Context, stakingCoinDenom string, farmerAcc sdk.AccAddress) {
 	store := ctx.KVStore(k.storeKey)
 	store.Delete(types.GetQueuedStakingKey(stakingCoinDenom, farmerAcc))
 	store.Delete(types.GetQueuedStakingIndexKey(farmerAcc, stakingCoinDenom))
 }
 
+// IterateQueuedStakings iterates through all queued stakings stored in
+// the store and invokes callback function for each item.
+// Stops the iteration when the callback function returns true.
 func (k Keeper) IterateQueuedStakings(ctx sdk.Context, cb func(stakingCoinDenom string, farmerAcc sdk.AccAddress, queuedStaking types.QueuedStaking) (stop bool)) {
 	store := ctx.KVStore(k.storeKey)
 	iter := sdk.KVStorePrefixIterator(store, types.QueuedStakingKeyPrefix)
@@ -116,6 +124,9 @@ func (k Keeper) IterateQueuedStakings(ctx sdk.Context, cb func(stakingCoinDenom
 	}
 }
 
+// IterateQueuedStakingsByFarmer iterates through all queued stakings
+// by farmer stored in the store and invokes callback function for each item.
+// Stops the iteration when the callback function returns true.
 func (k Keeper) IterateQueuedStakingsByFarmer(ctx sdk.Context, farmerAcc sdk.AccAddress, cb func(stakingCoinDenom string, queuedStaking types.QueuedStaking) (stop bool)) {
 	store := ctx.KVStore(k.storeKey)
 	iter := sdk.KVStorePrefixIterator(store, types.GetQueuedStakingByFarmerPrefix(farmerAcc))
@@ -129,6 +140,18 @@ func (k Keeper) IterateQueuedStakingsByFarmer(ctx sdk.Context, farmerAcc sdk.Acc
 	}
 }
 
+// GetAllQueuedCoinsByFarmer returns all coins that are queued for staking
+// by a farmer.
+func (k Keeper) GetAllQueuedCoinsByFarmer(ctx sdk.Context, farmerAcc sdk.AccAddress) sdk.Coins {
+	stakedCoins := sdk.NewCoins()
+	k.IterateQueuedStakingsByFarmer(ctx, farmerAcc, func(stakingCoinDenom string, queuedStaking types.QueuedStaking) (stop bool) {
+		stakedCoins = stakedCoins.Add(sdk.NewCoin(stakingCoinDenom, queuedStaking.Amount))
+		return false
+	})
+	return stakedCoins
+}
+
+// GetTotalStakings returns total stakings for given staking coin denom.
 func (k Keeper) GetTotalStakings(ctx sdk.Context, stakingCoinDenom string) (totalStakings types.TotalStakings, found bool) {
 	store := ctx.KVStore(k.storeKey)
 	bz := store.Get(types.GetTotalStakingsKey(stakingCoinDenom))
@@ -140,17 +163,21 @@ func (k Keeper) GetTotalStakings(ctx sdk.Context, stakingCoinDenom string) (tota
 	return
 }
 
+// SetTotalStakings sets total stakings for given staking coin denom.
 func (k Keeper) SetTotalStakings(ctx sdk.Context, stakingCoinDenom string, totalStakings types.TotalStakings) {
 	store := ctx.KVStore(k.storeKey)
 	bz := k.cdc.MustMarshal(&totalStakings)
 	store.Set(types.GetTotalStakingsKey(stakingCoinDenom), bz)
 }
 
+// DeleteTotalStakings deletes total stakings for given staking coin denom.
 func (k Keeper) DeleteTotalStakings(ctx sdk.Context, stakingCoinDenom string) {
 	store := ctx.KVStore(k.storeKey)
 	store.Delete(types.GetTotalStakingsKey(stakingCoinDenom))
 }
 
+// IncreaseTotalStakings increases total stakings for given staking coin denom
+// by given amount.
 func (k Keeper) IncreaseTotalStakings(ctx sdk.Context, stakingCoinDenom string, amount sdk.Int) {
 	totalStaking, found := k.GetTotalStakings(ctx, stakingCoinDenom)
 	if !found {
@@ -160,6 +187,8 @@ func (k Keeper) IncreaseTotalStakings(ctx sdk.Context, stakingCoinDenom string,
 	k.SetTotalStakings(ctx, stakingCoinDenom, totalStaking)
 }
 
+// DecreaseTotalStakings decreases total stakings for given staking coin denom
+// by given amount.
 func (k Keeper) DecreaseTotalStakings(ctx sdk.Context, stakingCoinDenom string, amount sdk.Int) {
 	totalStaking, found := k.GetTotalStakings(ctx, stakingCoinDenom)
 	if !found {
@@ -216,6 +245,7 @@ func (k Keeper) Stake(ctx sdk.Context, farmerAcc sdk.AccAddress, amount sdk.Coin
 }
 
 // Unstake unstakes an amount of staking coins from the staking reserve account.
+// It causes accumulated rewards to be withdrawn to the farmer.
 func (k Keeper) Unstake(ctx sdk.Context, farmerAcc sdk.AccAddress, amount sdk.Coins) error {
 	// TODO: send coins at once, not in every WithdrawRewards
 
@@ -285,6 +315,7 @@ func (k Keeper) Unstake(ctx sdk.Context, farmerAcc sdk.AccAddress, amount sdk.Co
 }
 
 // ProcessQueuedCoins moves queued coins into staked coins.
+// It causes accumulated rewards to be withdrawn to the farmer.
 func (k Keeper) ProcessQueuedCoins(ctx sdk.Context) {
 	k.IterateQueuedStakings(ctx, func(stakingCoinDenom string, farmerAcc sdk.AccAddress, queuedStaking types.QueuedStaking) (stop bool) {
 		staking, found := k.GetStaking(ctx, stakingCoinDenom, farmerAcc)
@@ -308,7 +339,9 @@ func (k Keeper) ProcessQueuedCoins(ctx sdk.Context) {
 	})
 }
 
-// ValidateStakingReservedAmount checks that the balance of StakingReserveAcc greater than the amount of staked, queued coins in all staking objects.
+// ValidateStakingReservedAmount checks that the balance of
+// StakingReserveAcc greater than the amount of staked, queued coins in all
+// staking objects.
 func (k Keeper) ValidateStakingReservedAmount(ctx sdk.Context) error {
 	reservedCoins := sdk.NewCoins()
 	k.IterateStakings(ctx, func(stakingCoinDenom string, _ sdk.AccAddress, staking types.Staking) (stop bool) {
diff --git a/x/farming/keeper/staking_test.go b/x/farming/keeper/staking_test.go
index 63210776..fdd568e7 100644
--- a/x/farming/keeper/staking_test.go
+++ b/x/farming/keeper/staking_test.go
@@ -127,7 +127,7 @@ func (suite *KeeperTestSuite) TestUnstake() {
 			} else {
 				if suite.NoError(err) {
 					suite.True(coinsEq(tc.remainingStaked, suite.keeper.GetAllStakedCoinsByFarmer(suite.ctx, suite.addrs[tc.addrIdx])))
-					suite.True(coinsEq(tc.remainingQueued, suite.keeper.GetAllQueuedStakedCoinsByFarmer(suite.ctx, suite.addrs[tc.addrIdx])))
+					suite.True(coinsEq(tc.remainingQueued, suite.keeper.GetAllQueuedCoinsByFarmer(suite.ctx, suite.addrs[tc.addrIdx])))
 				}
 			}
 		})
@@ -168,14 +168,14 @@ func (suite *KeeperTestSuite) TestProcessQueuedCoins() {
 				}
 			}
 
-			suite.Require().True(coinsEq(queuedCoins, suite.keeper.GetAllQueuedStakedCoinsByFarmer(suite.ctx, suite.addrs[0])))
+			suite.Require().True(coinsEq(queuedCoins, suite.keeper.GetAllQueuedCoinsByFarmer(suite.ctx, suite.addrs[0])))
 			suite.Require().True(coinsEq(stakedCoins, suite.keeper.GetAllStakedCoinsByFarmer(suite.ctx, suite.addrs[0])))
 
 			suite.keeper.ProcessQueuedCoins(suite.ctx)
 			stakedCoins = stakedCoins.Add(queuedCoins...)
 			queuedCoins = sdk.NewCoins()
 
-			suite.Require().True(coinsEq(queuedCoins, suite.keeper.GetAllQueuedStakedCoinsByFarmer(suite.ctx, suite.addrs[0])))
+			suite.Require().True(coinsEq(queuedCoins, suite.keeper.GetAllQueuedCoinsByFarmer(suite.ctx, suite.addrs[0])))
 			suite.Require().True(coinsEq(stakedCoins, suite.keeper.GetAllStakedCoinsByFarmer(suite.ctx, suite.addrs[0])))
 		}
 	}

From 5ffc807b415d623dca28f59bdca9a4cf5bc57a23 Mon Sep 17 00:00:00 2001
From: Hanjun Kim <hallazzang@gmail.com>
Date: Tue, 12 Oct 2021 14:36:38 +0900
Subject: [PATCH 5/6] chore: add comments for types

---
 x/farming/types/expected_keepers.go |  1 -
 x/farming/types/genesis.go          |  6 ++++++
 x/farming/types/keys.go             | 21 ++++++++++++++++++++-
 x/farming/types/plan.go             |  5 +++++
 x/farming/types/proposal.go         | 15 +++++++++++++++
 5 files changed, 46 insertions(+), 2 deletions(-)

diff --git a/x/farming/types/expected_keepers.go b/x/farming/types/expected_keepers.go
index 5984cb5b..1b3dc2d7 100644
--- a/x/farming/types/expected_keepers.go
+++ b/x/farming/types/expected_keepers.go
@@ -9,7 +9,6 @@ import (
 type BankKeeper interface {
 	SendCoins(ctx sdk.Context, fromAddr sdk.AccAddress, toAddr sdk.AccAddress, amt sdk.Coins) error
 	GetAllBalances(ctx sdk.Context, addr sdk.AccAddress) sdk.Coins
-	//GetBalance(ctx sdk.Context, addr sdk.AccAddress, denom string) sdk.Coin
 	SpendableCoins(ctx sdk.Context, addr sdk.AccAddress) sdk.Coins
 
 	SendCoinsFromModuleToAccount(ctx sdk.Context, senderModule string, recipientAddr sdk.AccAddress, amt sdk.Coins) error
diff --git a/x/farming/types/genesis.go b/x/farming/types/genesis.go
index f9d75f62..82ab8420 100644
--- a/x/farming/types/genesis.go
+++ b/x/farming/types/genesis.go
@@ -115,6 +115,7 @@ func ValidateGenesis(data GenesisState) error {
 	return nil
 }
 
+// Validate validates PlanRecord.
 func (record PlanRecord) Validate() error {
 	plan, err := UnpackPlan(&record.Plan)
 	if err != nil {
@@ -129,6 +130,7 @@ func (record PlanRecord) Validate() error {
 	return nil
 }
 
+// Validate validates StakingRecord.
 func (record StakingRecord) Validate() error {
 	if _, err := sdk.AccAddressFromBech32(record.Farmer); err != nil {
 		return err
@@ -142,6 +144,7 @@ func (record StakingRecord) Validate() error {
 	return nil
 }
 
+// Validate validates QueuedStakingRecord.
 func (record QueuedStakingRecord) Validate() error {
 	if _, err := sdk.AccAddressFromBech32(record.Farmer); err != nil {
 		return err
@@ -155,6 +158,7 @@ func (record QueuedStakingRecord) Validate() error {
 	return nil
 }
 
+// Validate validates HistoricalRewardsRecord.
 func (record HistoricalRewardsRecord) Validate() error {
 	if err := sdk.ValidateDenom(record.StakingCoinDenom); err != nil {
 		return err
@@ -165,6 +169,7 @@ func (record HistoricalRewardsRecord) Validate() error {
 	return nil
 }
 
+// Validate validates OutstandingRewardsRecord.
 func (record OutstandingRewardsRecord) Validate() error {
 	if err := sdk.ValidateDenom(record.StakingCoinDenom); err != nil {
 		return err
@@ -175,6 +180,7 @@ func (record OutstandingRewardsRecord) Validate() error {
 	return nil
 }
 
+// Validate validates CurrentEpochRecord.
 func (record CurrentEpochRecord) Validate() error {
 	if err := sdk.ValidateDenom(record.StakingCoinDenom); err != nil {
 		return err
diff --git a/x/farming/types/keys.go b/x/farming/types/keys.go
index 56dc0810..8ab0872b 100644
--- a/x/farming/types/keys.go
+++ b/x/farming/types/keys.go
@@ -50,42 +50,54 @@ func GetStakingKey(stakingCoinDenom string, farmerAcc sdk.AccAddress) []byte {
 	return append(append(StakingKeyPrefix, LengthPrefixString(stakingCoinDenom)...), farmerAcc...)
 }
 
+// GetStakingIndexKey returns an indexing key for a staking.
 func GetStakingIndexKey(farmerAcc sdk.AccAddress, stakingCoinDenom string) []byte {
 	return append(append(StakingIndexKeyPrefix, address.MustLengthPrefix(farmerAcc)...), []byte(stakingCoinDenom)...)
 }
 
+// GetStakingsByFarmerPrefix returns a key prefix used to iterate
+// stakings by a farmer.
 func GetStakingsByFarmerPrefix(farmerAcc sdk.AccAddress) []byte {
 	return append(StakingIndexKeyPrefix, address.MustLengthPrefix(farmerAcc)...)
 }
 
+// GetQueuedStakingKey returns a key for a queued staking.
 func GetQueuedStakingKey(stakingCoinDenom string, farmerAcc sdk.AccAddress) []byte {
 	return append(append(QueuedStakingKeyPrefix, LengthPrefixString(stakingCoinDenom)...), farmerAcc...)
 }
 
+// GetQueuedStakingIndexKey returns an indexing key for a queuded staking.
 func GetQueuedStakingIndexKey(farmerAcc sdk.AccAddress, stakingCoinDenom string) []byte {
 	return append(append(QueuedStakingIndexKeyPrefix, address.MustLengthPrefix(farmerAcc)...), []byte(stakingCoinDenom)...)
 }
 
+// GetQueuedStakingByFarmerPrefix returns a key prefix used to iterate
+// queued stakings by a farmer.
 func GetQueuedStakingByFarmerPrefix(farmerAcc sdk.AccAddress) []byte {
 	return append(QueuedStakingIndexKeyPrefix, address.MustLengthPrefix(farmerAcc)...)
 }
 
+// GetTotalStakingsKey returns a key for a total stakings info.
 func GetTotalStakingsKey(stakingCoinDenom string) []byte {
 	return append(TotalStakingKeyPrefix, []byte(stakingCoinDenom)...)
 }
 
+// GetHistoricalRewardsKey returns a key for a historical rewards record.
 func GetHistoricalRewardsKey(stakingCoinDenom string, epoch uint64) []byte {
 	return append(append(HistoricalRewardsKeyPrefix, LengthPrefixString(stakingCoinDenom)...), sdk.Uint64ToBigEndian(epoch)...)
 }
 
+// GetCurrentEpochKey returns a key for a current epoch info.
 func GetCurrentEpochKey(stakingCoinDenom string) []byte {
 	return append(CurrentEpochKeyPrefix, []byte(stakingCoinDenom)...)
 }
 
+// GetOutstandingRewardsKey returns a key for an outstanding rewards record.
 func GetOutstandingRewardsKey(stakingCoinDenom string) []byte {
 	return append(OutstandingRewardsKeyPrefix, []byte(stakingCoinDenom)...)
 }
 
+// ParseStakingKey parses a staking key.
 func ParseStakingKey(key []byte) (stakingCoinDenom string, farmerAcc sdk.AccAddress) {
 	if !bytes.HasPrefix(key, StakingKeyPrefix) {
 		panic("key does not have proper prefix")
@@ -96,6 +108,7 @@ func ParseStakingKey(key []byte) (stakingCoinDenom string, farmerAcc sdk.AccAddr
 	return
 }
 
+// ParseStakingIndexKey parses a staking index key.
 func ParseStakingIndexKey(key []byte) (farmerAcc sdk.AccAddress, stakingCoinDenom string) {
 	if !bytes.HasPrefix(key, StakingIndexKeyPrefix) {
 		panic("key does not have proper prefix")
@@ -106,6 +119,7 @@ func ParseStakingIndexKey(key []byte) (farmerAcc sdk.AccAddress, stakingCoinDeno
 	return
 }
 
+// ParseQueuedStakingKey parses a queued staking key.
 func ParseQueuedStakingKey(key []byte) (stakingCoinDenom string, farmerAcc sdk.AccAddress) {
 	if !bytes.HasPrefix(key, QueuedStakingKeyPrefix) {
 		panic("key does not have proper prefix")
@@ -116,6 +130,7 @@ func ParseQueuedStakingKey(key []byte) (stakingCoinDenom string, farmerAcc sdk.A
 	return
 }
 
+// ParseQueuedStakingIndexKey parses a queued staking index key.
 func ParseQueuedStakingIndexKey(key []byte) (farmerAcc sdk.AccAddress, stakingCoinDenom string) {
 	if !bytes.HasPrefix(key, QueuedStakingIndexKeyPrefix) {
 		panic("key does not have proper prefix")
@@ -126,6 +141,7 @@ func ParseQueuedStakingIndexKey(key []byte) (farmerAcc sdk.AccAddress, stakingCo
 	return
 }
 
+// ParseHistoricalRewardsKey parses a historical rewards key.
 func ParseHistoricalRewardsKey(key []byte) (stakingCoinDenom string, epoch uint64) {
 	if !bytes.HasPrefix(key, HistoricalRewardsKeyPrefix) {
 		panic("key does not have proper prefix")
@@ -136,6 +152,7 @@ func ParseHistoricalRewardsKey(key []byte) (stakingCoinDenom string, epoch uint6
 	return
 }
 
+// ParseCurrentEpochKey parses a current epoch key.
 func ParseCurrentEpochKey(key []byte) (stakingCoinDenom string) {
 	if !bytes.HasPrefix(key, CurrentEpochKeyPrefix) {
 		panic("key does not have proper prefix")
@@ -144,6 +161,7 @@ func ParseCurrentEpochKey(key []byte) (stakingCoinDenom string) {
 	return
 }
 
+// ParseOutstandingRewardsKey parses an outstanding rewards key.
 func ParseOutstandingRewardsKey(key []byte) (stakingCoinDenom string) {
 	if !bytes.HasPrefix(key, OutstandingRewardsKeyPrefix) {
 		panic("key does not have proper prefix")
@@ -152,7 +170,8 @@ func ParseOutstandingRewardsKey(key []byte) (stakingCoinDenom string) {
 	return
 }
 
-// LengthPrefixString is LengthPrefix for string.
+// LengthPrefixString returns length-prefixed bytes representation
+// of a string.
 func LengthPrefixString(s string) []byte {
 	bz := []byte(s)
 	bzLen := len(bz)
diff --git a/x/farming/types/plan.go b/x/farming/types/plan.go
index da70d66b..c2e33ab2 100644
--- a/x/farming/types/plan.go
+++ b/x/farming/types/plan.go
@@ -210,6 +210,7 @@ func (plan BasePlan) MarshalYAML() (interface{}, error) {
 	return string(bz), err
 }
 
+// NewFixedAmountPlan returns a new fixed amount plan.
 func NewFixedAmountPlan(basePlan *BasePlan, epochAmount sdk.Coins) *FixedAmountPlan {
 	return &FixedAmountPlan{
 		BasePlan:    basePlan,
@@ -217,6 +218,7 @@ func NewFixedAmountPlan(basePlan *BasePlan, epochAmount sdk.Coins) *FixedAmountP
 	}
 }
 
+// NewRatioPlan returns a new ratio plan.
 func NewRatioPlan(basePlan *BasePlan, epochRatio sdk.Dec) *RatioPlan {
 	return &RatioPlan{
 		BasePlan:   basePlan,
@@ -224,6 +226,7 @@ func NewRatioPlan(basePlan *BasePlan, epochRatio sdk.Dec) *RatioPlan {
 	}
 }
 
+// PlanI represents a farming plan.
 type PlanI interface {
 	proto.Message
 
@@ -362,6 +365,8 @@ func IsPlanActiveAt(plan PlanI, t time.Time) bool {
 	return !plan.GetStartTime().After(t) && plan.GetEndTime().After(t)
 }
 
+// PrivatePlanFarmingPoolAddress returns a unique farming pool address
+// for a newly created plan.
 func PrivatePlanFarmingPoolAddress(name string, planId uint64) sdk.AccAddress {
 	poolAddrName := strings.Join([]string{PrivatePlanFarmingPoolAddrPrefix, fmt.Sprint(planId), name}, PoolAddrSplitter)
 	return address.Module(ModuleName, []byte(poolAddrName))
diff --git a/x/farming/types/proposal.go b/x/farming/types/proposal.go
index 2ee89edd..52a5c2bf 100644
--- a/x/farming/types/proposal.go
+++ b/x/farming/types/proposal.go
@@ -104,14 +104,21 @@ func NewAddRequestProposal(
 	}
 }
 
+// IsForFixedAmountPlan returns true if the request is for
+// fixed amount plan.
+// It checks if EpochAmount is not zero.
 func (p *AddRequestProposal) IsForFixedAmountPlan() bool {
 	return !p.EpochAmount.IsZero()
 }
 
+// IsForRatioPlan returns true if the request is for
+// ratio plan.
+// It checks if EpochRatio is not zero.
 func (p *AddRequestProposal) IsForRatioPlan() bool {
 	return !p.EpochRatio.IsNil() && !p.EpochRatio.IsZero()
 }
 
+// Validate validates AddRequestProposal.
 func (p *AddRequestProposal) Validate() error {
 	if len(p.Name) > MaxNameLength {
 		return sdkerrors.Wrapf(ErrInvalidPlanNameLength, "plan name cannot be longer than max length of %d", MaxNameLength)
@@ -165,14 +172,21 @@ func NewUpdateRequestProposal(
 	}
 }
 
+// IsForFixedAmountPlan returns true if the request is for
+// fixed amount plan.
+// It checks if EpochAmount is not zero.
 func (p *UpdateRequestProposal) IsForFixedAmountPlan() bool {
 	return !p.EpochAmount.IsZero()
 }
 
+// IsForRatioPlan returns true if the request is for
+// ratio plan.
+// It checks if EpochRatio is not zero.
 func (p *UpdateRequestProposal) IsForRatioPlan() bool {
 	return !p.EpochRatio.IsNil() && !p.EpochRatio.IsZero()
 }
 
+// Validate validates UpdateRequestProposal.
 func (p *UpdateRequestProposal) Validate() error {
 	if p.PlanId == 0 {
 		return sdkerrors.Wrapf(sdkerrors.ErrInvalidRequest, "invalid plan id: %d", p.PlanId)
@@ -213,6 +227,7 @@ func NewDeleteRequestProposal(id uint64) *DeleteRequestProposal {
 	}
 }
 
+// Validate validates DeleteRequestProposal.
 func (p *DeleteRequestProposal) Validate() error {
 	if p.PlanId == 0 {
 		return sdkerrors.Wrapf(sdkerrors.ErrInvalidRequest, "invalid plan id: %d", p.PlanId)

From 86d822434eed524aa18d6c1d4c31b461ec4cf6f8 Mon Sep 17 00:00:00 2001
From: Hanjun Kim <hallazzang@gmail.com>
Date: Thu, 14 Oct 2021 13:37:54 +0900
Subject: [PATCH 6/6] chore: apply changes from code review

---
 x/farming/keeper/reward.go | 1 -
 1 file changed, 1 deletion(-)

diff --git a/x/farming/keeper/reward.go b/x/farming/keeper/reward.go
index cbbe54d6..f584cddb 100644
--- a/x/farming/keeper/reward.go
+++ b/x/farming/keeper/reward.go
@@ -418,7 +418,6 @@ func (k Keeper) AllocateRewards(ctx sdk.Context) error {
 // ValidateRemainingRewardsAmount checks that the balance of the
 // rewards reserve pool is greater than the total amount of
 // unwithdrawn rewards.
-// TODO: correct comment above
 func (k Keeper) ValidateRemainingRewardsAmount(ctx sdk.Context) error {
 	remainingRewards := sdk.NewCoins()
 	k.IterateStakings(ctx, func(stakingCoinDenom string, farmerAcc sdk.AccAddress, staking types.Staking) (stop bool) {