refactor: use a more modern writing style to simplify code

accounts/checkers.go

@@ -494,7 +494,6 @@ func filterInvoices(ctx context.Context,
 	// after filtering.
 	var filteredInvoices []*lnrpc.Invoice
 	for _, invoice := range t.Invoices {
-		invoice := invoice
 
 		hash, err := lntypes.MakeHash(invoice.RHash)
 		if err != nil {
@@ -523,7 +522,6 @@ func filterPayments(ctx context.Context,
 	// after filtering.
 	var filteredPayments []*lnrpc.Payment
 	for _, payment := range t.Payments {
-		payment := payment
 
 		hash, err := lntypes.MakeHashFromStr(payment.PaymentHash)
 		if err != nil {
@@ -549,10 +547,7 @@ func checkSend(ctx context.Context, chainParams *chaincfg.Params,
 		return err
 	}
 
-	sendAmt := lnwire.NewMSatFromSatoshis(btcutil.Amount(amt))
-	if lnwire.MilliSatoshi(amtMsat) > sendAmt {
-		sendAmt = lnwire.MilliSatoshi(amtMsat)
-	}
+	sendAmt := max(lnwire.MilliSatoshi(amtMsat), lnwire.NewMSatFromSatoshis(btcutil.Amount(amt)))
 
 	// We require that a payment hash is set, which we either read from the
 	// payment hash from the invoice or from the request.
@@ -697,10 +692,9 @@ func checkSendToRoute(ctx context.Context, service Service, paymentHash []byte,
 		return fmt.Errorf("invalid route")
 	}
 
-	sendAmt := lnwire.NewMSatFromSatoshis(btcutil.Amount(route.TotalAmt)) // nolint
-	if lnwire.MilliSatoshi(route.TotalAmtMsat) > sendAmt {
-		sendAmt = lnwire.MilliSatoshi(route.TotalAmtMsat)
-	}
+	sendAmt := max(
+		// nolint
+		lnwire.MilliSatoshi(route.TotalAmtMsat), lnwire.NewMSatFromSatoshis(btcutil.Amount(route.TotalAmt)))
 
 	log.Tracef("Handling send request for payment with hash: %s and "+
 		"amount: %d", hash, sendAmt)
@@ -709,10 +703,9 @@ func checkSendToRoute(ctx context.Context, service Service, paymentHash []byte,
 	// not every single satoshi of an account can be used up. But it
 	// prevents an account from going into a negative balance if we only
 	// check for the amount to send but then later debit the full amount.
-	fee := lnwire.NewMSatFromSatoshis(btcutil.Amount(route.TotalFees)) // nolint
-	if lnwire.MilliSatoshi(route.TotalFeesMsat) > fee {
-		fee = lnwire.MilliSatoshi(route.TotalFeesMsat)
-	}
+	fee := max(
+		// nolint
+		lnwire.MilliSatoshi(route.TotalFeesMsat), lnwire.NewMSatFromSatoshis(btcutil.Amount(route.TotalFees)))
 	sendAmt += fee
 
 	err = service.CheckBalance(ctx, acct.ID, sendAmt)

accounts/checkers_test.go

@@ -450,7 +450,6 @@ func TestAccountCheckers(t *testing.T) {
 	}}
 
 	for _, tc := range testCases {
-		tc := tc
 
 		t.Run(tc.name, func(tt *testing.T) {
 			tt.Parallel()

accounts/interceptor.go

@@ -30,9 +30,9 @@ var (
 	// caveatPrefix is the prefix that is used for custom caveats that are
 	// used by the account system. This prefix is used to identify the
 	// custom caveat and extract the condition (the AccountID) from it.
-	caveatPrefix = []byte(fmt.Sprintf(
+	caveatPrefix = fmt.Appendf(nil,
 		"%s %s ", macaroons.CondLndCustom, CondAccount,
-	))
+	)
 )
 
 // Name returns the name of the interceptor.

accounts/rpcserver.go

@@ -223,7 +223,6 @@ func (s *RPCServer) ListAccounts(ctx context.Context,
 	// Map the response into the proper response type and return it.
 	rpcAccounts := make([]*litrpc.Account, len(accts))
 	for i, acct := range accts {
-		acct := acct
 
 		rpcAccounts[i] = marshalAccount(acct)
 	}

accounts/service.go

@@ -116,16 +116,13 @@ func (s *InterceptorService) Start(ctx context.Context,
 			"accounts: %w", err)
 	}
 	for _, acct := range existingAccounts {
-		acct := acct
 		for invoice := range acct.Invoices {
-			invoice := invoice
 			s.invoiceToAccount[invoice] = acct.ID
 		}
 
 		// Let's also resume tracking payments that have a last recorded
 		// state of being in-flight.
 		for hash, entry := range acct.Payments {
-			entry := entry
 			if !successState(entry.Status) {
 				err := s.TrackPayment(
 					ctx, acct.ID, hash, entry.FullAmount,

firewalldb/privacy_mapper.go

@@ -7,6 +7,7 @@ import (
 	"encoding/hex"
 	"errors"
 	"fmt"
+	"maps"
 	"math/big"
 	"strconv"
 	"strings"
@@ -340,9 +341,7 @@ func (p *PrivacyMapPairs) Add(pairs map[string]string) error {
 	}
 
 	// In our second pass, we can add the new pairs to our set.
-	for realStr, pseudoStr := range pairs {
-		p.pairs[realStr] = pseudoStr
-	}
+	maps.Copy(p.pairs, pairs)
 
 	return nil
 }

rules/channel_restrictions_test.go

@@ -227,7 +227,6 @@ func TestChannelRestrictRealToPseudo(t *testing.T) {
 	}
 
 	for _, test := range tests {
-		test := test
 		t.Run(test.name, func(t *testing.T) {
 			t.Parallel()
 

rules/peer_restrictions_test.go

@@ -259,7 +259,6 @@ func TestPeerRestrictRealToPseudo(t *testing.T) {
 	}
 
 	for _, test := range tests {
-		test := test
 		t.Run(test.name, func(t *testing.T) {
 			t.Parallel()
 

session/tlv_test.go

@@ -122,7 +122,6 @@ func TestSerializeDeserializeSession(t *testing.T) {
 	}
 
 	for _, test := range tests {
-		test := test
 		t.Run(test.name, func(t *testing.T) {
 			t.Parallel()