test(campaign): simulation improvements (#726)

* override send-enabled params for simulation

* finalize `SimulateMsgSendVouchers`

Co-authored-by: Alex Johnson <alex.johnson@tendermint.com>
Co-authored-by: Lucas Bertrand <lucas.bertrand.22@gmail.com>

app/simutil/app_state.go

@@ -145,6 +145,10 @@ func CustomAppStateFn(cdc codec.JSONCodec, simManager *module.SimulationManager)
 			})
 		}
 
+		// override bank parameters to always enable transfers
+		bankState.Params.SendEnabled = banktypes.SendEnabledParams{}
+		bankState.Params.DefaultSendEnabled = true
+
 		// change appState back
 		rawState[stakingtypes.ModuleName] = cdc.MustMarshalJSON(stakingState)
 		rawState[banktypes.ModuleName] = cdc.MustMarshalJSON(bankState)

x/campaign/simulation/simulation.go

@@ -335,7 +335,6 @@ func SimulateMsgUnredeemVouchers(
 }
 
 // SimulateMsgSendVouchers simulates a Msg message from the bank module with vouchers
-// TODO: This message constantly fails in simulation log, investigate why
 func SimulateMsgSendVouchers(
 	ak types.AccountKeeper,
 	bk types.BankKeeper,
@@ -346,7 +345,7 @@ func SimulateMsgSendVouchers(
 	) (simtypes.OperationMsg, []simtypes.FutureOperation, error) {
 		_, simAccount, vouchers, found := GetAccountWithVouchers(ctx, bk, k, accs, false)
 		if !found {
-			return simtypes.NoOpMsg(types.ModuleName, banktypes.TypeMsgSend, "skip send vouchers"), nil, nil
+			return simtypes.NoOpMsg(banktypes.ModuleName, banktypes.TypeMsgSend, "skip send vouchers"), nil, nil
 		}
 
 		// Select a random receiver account

x/campaign/simulation/store.go

@@ -164,11 +164,6 @@ func GetAccountWithVouchers(
 			}
 		}
 
-		// Look for accounts with at least 10 vouchers
-		if coin.Amount.Int64() < 10 {
-			return false
-		}
-
 		found = true
 		accountAddr = addr
 		return true
@@ -179,19 +174,14 @@ func GetAccountWithVouchers(
 		return 0, account, coins, false
 	}
 
-	// Fetch all the vouchers of the campaign owned by the account
+	// Fetch from the vouchers of the campaign owned by the account
 	bk.IterateAccountBalances(ctx, accountAddr, func(coin sdk.Coin) bool {
 		coinCampID, err := types.VoucherCampaign(coin.Denom)
 		if err == nil && coinCampID == campID {
-
-			// Get a portion of the balance
-			// If the balance is 1, we don't include it in the vouchers
-			// There is a issue: insufficient fees that can occur when the whole balance for a voucher is sent
-			// TODO: Investigate this issue
-			if coin.Amount.Int64() > 1 {
-				coin.Amount = coin.Amount.Quo(sdk.NewInt(2))
-				coins = append(coins, coin)
-			}
+			// retain a random portion of the balance in the range [0, coin.Amount)
+			retainAmt := sdk.NewInt(rand.Int63n(coin.Amount.Int64()))
+			coin.Amount = coin.Amount.Sub(retainAmt)
+			coins = append(coins, coin)
 		}
 		return false
 	})