From c56457c869042daf04b0746c8c8fc61ca4b0f61a Mon Sep 17 00:00:00 2001
From: Bjarne Magnussen <bjarne@magnussen.casa>
Date: Wed, 19 Aug 2020 12:09:35 +0200
Subject: [PATCH] chanfunding: add test for a non-zero change

---
 lnwallet/chanfunding/coin_select_test.go | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/lnwallet/chanfunding/coin_select_test.go b/lnwallet/chanfunding/coin_select_test.go
index 36cc64fd..3b02c34b 100644
--- a/lnwallet/chanfunding/coin_select_test.go
+++ b/lnwallet/chanfunding/coin_select_test.go
@@ -244,6 +244,27 @@ func TestCoinSelectSubtractFees(t *testing.T) {
 			expectedFundingAmt: 1*btcutil.SatoshiPerBitcoin - fundingFee(feeRate, 1, false),
 			expectedChange:     0,
 		},
+		{
+			// We have 1.0 BTC available and spend half of it. This
+			// should lead to a funding TX with a change output.
+			name: "spend with change",
+			coins: []Coin{
+				{
+					TxOut: wire.TxOut{
+						PkScript: p2wkhScript,
+						Value:    1 * btcutil.SatoshiPerBitcoin,
+					},
+				},
+			},
+			spendValue: 0.5 * btcutil.SatoshiPerBitcoin,
+
+			// The one and only input will be selected.
+			expectedInput: []btcutil.Amount{
+				1 * btcutil.SatoshiPerBitcoin,
+			},
+			expectedFundingAmt: 0.5*btcutil.SatoshiPerBitcoin - fundingFee(feeRate, 1, true),
+			expectedChange:     0.5 * btcutil.SatoshiPerBitcoin,
+		},
 		{
 			// The total funds available is below the dust limit
 			// after paying fees.