Merge pull request #10087 from starius/estimate-feerate-allow-1

walletrpc: allow conf_target=1 in EstimateFee and FundPsbt

docs/release-notes/release-notes-0.20.0.md

@@ -45,6 +45,10 @@
 
 ## Functional Enhancements
 
+* RPCs `walletrpc.EstimateFee` and `walletrpc.FundPsbt` now
+   [allow](https://github.com/lightningnetwork/lnd/pull/10087)
+  `conf_target=1`. Previously they required `conf_target >= 2`.
+
 ## RPC Additions
 * When querying [`ForwardingEvents`](https://github.com/lightningnetwork/lnd/pull/9813)
 logs, the response now include the incoming and outgoing htlc indices of the payment 

itest/list_on_test.go

@@ -731,6 +731,10 @@ var allTestCases = []*lntest.TestCase{
 		Name:     "delete canceled invoice",
 		TestFunc: testDeleteCanceledInvoice,
 	},
+	{
+		Name:     "estimate fee",
+		TestFunc: testEstimateFee,
+	},
 }
 
 // appendPrefixed is used to add a prefix to each test name in the subtests

itest/lnd_misc_test.go

@@ -5,6 +5,7 @@ import (
 	"encoding/hex"
 	"fmt"
 	"os"
+	"testing"
 
 	"github.com/btcsuite/btcd/btcutil"
 	"github.com/btcsuite/btcd/chaincfg/chainhash"
@@ -1593,3 +1594,49 @@ func testReorgNotifications(ht *lntest.HarnessTest) {
 	require.NotNil(ht, spendDetails)
 	require.Equal(ht, txid2a[:], spendDetails.SpendingTxHash)
 }
+
+// testEstimateFee tests walletrpc.EstimateFee API.
+func testEstimateFee(ht *lntest.HarnessTest) {
+	alice := ht.NewNode("Alice", nil)
+
+	ctx := context.Background()
+
+	testCases := []struct {
+		name        string
+		confTarget  int32
+		errContains string
+	}{
+		{
+			name:       "conf target 1",
+			confTarget: 1,
+		},
+		{
+			name:        "conf target 0",
+			confTarget:  0,
+			errContains: "must be greater than 0",
+		},
+		{
+			name:        "conf target -1",
+			confTarget:  -1,
+			errContains: "must be greater than 0",
+		},
+	}
+
+	for _, tc := range testCases {
+		ht.Run(tc.name, func(t *testing.T) {
+			req := &walletrpc.EstimateFeeRequest{
+				ConfTarget: tc.confTarget,
+			}
+			resp, err := alice.RPC.WalletKit.EstimateFee(ctx, req)
+
+			if tc.errContains != "" {
+				require.ErrorContains(t, err, tc.errContains)
+				return
+			}
+
+			require.NoError(t, err)
+			require.NotZero(t, resp.SatPerKw)
+			require.NotZero(t, resp.MinRelayFeeSatPerKw)
+		})
+	}
+}

itest/lnd_psbt_test.go

@@ -1253,8 +1253,8 @@ func fundPsbtCoinSelect(t testing.TB, node *node.HarnessNode,
 		Template: &walletrpc.FundPsbtRequest_CoinSelect{
 			CoinSelect: cs,
 		},
-		Fees: &walletrpc.FundPsbtRequest_SatPerVbyte{
-			SatPerVbyte: 50,
+		Fees: &walletrpc.FundPsbtRequest_TargetConf{
+			TargetConf: 1,
 		},
 	})
 

lnrpc/walletrpc/walletkit_server.go

@@ -843,12 +843,10 @@ func (w *WalletKit) SendOutputs(ctx context.Context,
 func (w *WalletKit) EstimateFee(ctx context.Context,
 	req *EstimateFeeRequest) (*EstimateFeeResponse, error) {
 
-	switch {
-	// A confirmation target of zero doesn't make any sense. Similarly, we
-	// reject confirmation targets of 1 as they're unreasonable.
-	case req.ConfTarget == 0 || req.ConfTarget == 1:
+	// A confirmation target of zero or lower doesn't make any sense.
+	if req.ConfTarget <= 0 {
 		return nil, fmt.Errorf("confirmation target must be greater " +
-			"than 1")
+			"than 0")
 	}
 
 	satPerKw, err := w.cfg.FeeEstimator.EstimateFeePerKW(
@@ -1557,9 +1555,9 @@ func (w *WalletKit) FundPsbt(_ context.Context,
 	// Estimate the fee by the target number of blocks to confirmation.
 	case req.GetTargetConf() != 0:
 		targetConf := req.GetTargetConf()
-		if targetConf < 2 {
+		if targetConf < 1 {
 			return nil, fmt.Errorf("confirmation target must be " +
-				"greater than 1")
+				"greater than 0")
 		}
 
 		feeSatPerKW, err = w.cfg.FeeEstimator.EstimateFeePerKW(