From 16c0ce40797a283a85cb279144f136dd5554389a Mon Sep 17 00:00:00 2001
From: myxmaster <77545287+myxmaster@users.noreply.github.com>
Date: Wed, 23 Oct 2024 23:37:54 +0200
Subject: [PATCH] chanfunding: improve sanityCheckFee error message for clarity
 and update coin_select_test accordingly

---
 lnwallet/chanfunding/coin_select.go      |  4 ++--
 lnwallet/chanfunding/coin_select_test.go | 10 +++++-----
 2 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/lnwallet/chanfunding/coin_select.go b/lnwallet/chanfunding/coin_select.go
index b9ff1be21f6..e2c85c9d342 100644
--- a/lnwallet/chanfunding/coin_select.go
+++ b/lnwallet/chanfunding/coin_select.go
@@ -150,8 +150,8 @@ func sanityCheckFee(totalOut, fee btcutil.Amount) error {
 	// TODO(halseth): smarter fee limit. Make configurable or dynamic wrt
 	// total funding size?
 	if fee > totalOut/5 {
-		return fmt.Errorf("fee %v on total output value %v", fee,
-			totalOut)
+		return fmt.Errorf("fee (%v) exceeds 20%% of total output (%v)",
+			fee, totalOut)
 	}
 	return nil
 }
diff --git a/lnwallet/chanfunding/coin_select_test.go b/lnwallet/chanfunding/coin_select_test.go
index 26a257b37f8..a20d27ac95a 100644
--- a/lnwallet/chanfunding/coin_select_test.go
+++ b/lnwallet/chanfunding/coin_select_test.go
@@ -411,8 +411,8 @@ func TestCalculateChangeAmount(t *testing.T) {
 		feeWithChange: 45,
 		dustLimit:     5,
 
-		expectErr: "fee 0.00000045 BTC on total output value " +
-			"0.00000055",
+                expectErr: "fee (0.00000045 BTC) exceeds 20% of total output " +
+                        "(0.00000055 BTC)",
 	}, {
 		name:          "invalid usage of function",
 		feeNoChange:   5,
@@ -606,7 +606,7 @@ func TestCoinSelectSubtractFees(t *testing.T) {
 			},
 			spendValue: 5 * fundingFee(highFeeRate, 1, false),
 
-			expectErr: "fee <amt> BTC on total output value <amt> BTC",
+			expectErr: "fee (<amt> BTC) exceeds <amt>% of total output (<amt> BTC)",
 		},
 	}
 
@@ -812,8 +812,8 @@ func TestCoinSelectUpToAmount(t *testing.T) {
 		minValue: minValue,
 		maxValue: 16 * fundingFee(feeRate, 1, false),
 
-		expectErr: "fee 0.00000192 BTC on total output value " +
-			"0.00000768 BTC",
+                expectErr: "fee (0.00000192 BTC) exceeds 20% of total output " +
+                        "(0.00000768 BTC)",
 	}, {
 		// This test makes sure that the implementation detail of using
 		// CoinSelect and CoinSelectSubtractFees is done correctly.