improve pool config update

Author: keithsue

x/lending/keeper/msg_server_pool.go

@@ -181,7 +181,9 @@ func (m msgServer) UpdatePoolConfig(goCtx context.Context, msg *types.MsgUpdateP
 	}
 
 	pool := m.GetPool(ctx, msg.PoolId)
+
 	m.UpdatePoolStatus(ctx, pool, &msg.Config)
+	m.OnPoolTranchesConfigChanged(ctx, pool, msg.Config.Tranches)
 
 	pool.Config = msg.Config
 	m.SetPool(ctx, pool)

x/lending/keeper/pool.go

@@ -200,6 +200,17 @@ func (k Keeper) UpdatePoolStatus(ctx sdk.Context, pool *types.LendingPool, newCo
 	}
 }
 
+// OnPoolTranchesConfigChanged is called when the pool tranches config changes
+func (k Keeper) OnPoolTranchesConfigChanged(ctx sdk.Context, pool *types.LendingPool, newTranchesConfig []types.PoolTrancheConfig) {
+	for _, newConfig := range newTranchesConfig {
+		_, found := types.GetTrancheConfig(pool.Config.Tranches, newConfig.Maturity)
+		if !found {
+			// add the new tranche to pool if the tranche does not exist
+			pool.Tranches = append(pool.Tranches, types.NewTranche(newConfig))
+		}
+	}
+}
+
 // NormalizePool normalizes the given pool
 func (k Keeper) NormalizePool(ctx sdk.Context, pool *types.LendingPool) {
 	if pool.TotalBorrowed.IsNegative() {

x/lending/types/lending.go

@@ -264,13 +264,20 @@ func GetTranche(tranches []PoolTranche, maturity int64) (*PoolTranche, bool) {
 	return nil, false
 }
 
+// NewTranche creates a new tranche from the given tranche config
+func NewTranche(config PoolTrancheConfig) PoolTranche {
+	return PoolTranche{
+		Maturity:    config.Maturity,
+		BorrowIndex: InitialBorrowIndex,
+	}
+}
+
 // NewTranches initializes the pool tranches from the given tranche configs
 func NewTranches(trancheConfigs []PoolTrancheConfig) []PoolTranche {
 	tranches := make([]PoolTranche, len(trancheConfigs))
 
 	for i, config := range trancheConfigs {
-		tranches[i].Maturity = config.Maturity
-		tranches[i].BorrowIndex = InitialBorrowIndex
+		tranches[i] = NewTranche(config)
 	}
 
 	return tranches