discovery+graph: convert errors from codes to variables

In preparation for moving funding transaction validiation from the
Builder to the Gossiper in later commit, we first convert these graph
Error Codes to normal error variables. This will help make the later
commit a pure code move.

discovery/gossiper.go

@@ -2678,10 +2678,9 @@ func (d *AuthenticatedGossiper) handleChanAnnouncement(nMsg *networkMsg,
 
 			return anns, true
 
-		case graph.IsError(
-			err, graph.ErrNoFundingTransaction,
-			graph.ErrInvalidFundingOutput,
-		):
+		case errors.Is(err, graph.ErrNoFundingTransaction),
+			errors.Is(err, graph.ErrInvalidFundingOutput):
+
 			key := newRejectCacheKey(
 				scid.ToUint64(),
 				sourceToPub(nMsg.source),
@@ -2695,7 +2694,7 @@ func (d *AuthenticatedGossiper) handleChanAnnouncement(nMsg *networkMsg,
 				d.banman.incrementBanScore(nMsg.peer.PubKey())
 			}
 
-		case graph.IsError(err, graph.ErrChannelSpent):
+		case errors.Is(err, graph.ErrChannelSpent):
 			key := newRejectCacheKey(
 				scid.ToUint64(),
 				sourceToPub(nMsg.source),

discovery/gossiper_test.go

@@ -24,7 +24,6 @@ import (
 	"github.com/lightningnetwork/lnd/batch"
 	"github.com/lightningnetwork/lnd/chainntnfs"
 	"github.com/lightningnetwork/lnd/channeldb"
-	"github.com/lightningnetwork/lnd/fn/v2"
 	"github.com/lightningnetwork/lnd/graph"
 	graphdb "github.com/lightningnetwork/lnd/graph/db"
 	"github.com/lightningnetwork/lnd/graph/db/models"
@@ -76,13 +75,13 @@ var (
 type mockGraphSource struct {
 	bestHeight uint32
 
-	mu             sync.Mutex
-	nodes          []models.LightningNode
-	infos          map[uint64]models.ChannelEdgeInfo
-	edges          map[uint64][]models.ChannelEdgePolicy
-	zombies        map[uint64][][33]byte
-	chansToReject  map[uint64]struct{}
-	addEdgeErrCode fn.Option[graph.ErrorCode]
+	mu            sync.Mutex
+	nodes         []models.LightningNode
+	infos         map[uint64]models.ChannelEdgeInfo
+	edges         map[uint64][]models.ChannelEdgePolicy
+	zombies       map[uint64][][33]byte
+	chansToReject map[uint64]struct{}
+	addEdgeErr    error
 }
 
 func newMockRouter(height uint32) *mockGraphSource {
@@ -113,10 +112,8 @@ func (r *mockGraphSource) AddEdge(info *models.ChannelEdgeInfo,
 	r.mu.Lock()
 	defer r.mu.Unlock()
 
-	if r.addEdgeErrCode.IsSome() {
-		return graph.NewErrf(
-			r.addEdgeErrCode.UnsafeFromSome(), "received error",
-		)
+	if r.addEdgeErr != nil {
+		return r.addEdgeErr
 	}
 
 	if _, ok := r.infos[info.ChannelID]; ok {
@@ -131,12 +128,12 @@ func (r *mockGraphSource) AddEdge(info *models.ChannelEdgeInfo,
 	return nil
 }
 
-func (r *mockGraphSource) resetAddEdgeErrCode() {
-	r.addEdgeErrCode = fn.None[graph.ErrorCode]()
+func (r *mockGraphSource) resetAddEdgeErr() {
+	r.addEdgeErr = nil
 }
 
-func (r *mockGraphSource) setAddEdgeErrCode(code graph.ErrorCode) {
-	r.addEdgeErrCode = fn.Some[graph.ErrorCode](code)
+func (r *mockGraphSource) setAddEdgeErr(err error) {
+	r.addEdgeErr = err
 }
 
 func (r *mockGraphSource) queueValidationFail(chanID uint64) {
@@ -4185,7 +4182,7 @@ func TestChanAnnBanningNonChanPeer(t *testing.T) {
 		remoteKeyPriv2.PubKey(), nil, nil, atomic.Bool{},
 	}
 
-	ctx.router.setAddEdgeErrCode(graph.ErrInvalidFundingOutput)
+	ctx.router.setAddEdgeErr(graph.ErrInvalidFundingOutput)
 
 	// Loop 100 times to get nodePeer banned.
 	for i := 0; i < 100; i++ {
@@ -4199,11 +4196,7 @@ func TestChanAnnBanningNonChanPeer(t *testing.T) {
 		case err = <-ctx.gossiper.ProcessRemoteAnnouncement(
 			ca, nodePeer1,
 		):
-			require.True(
-				t, graph.IsError(
-					err, graph.ErrInvalidFundingOutput,
-				),
-			)
+			require.ErrorIs(t, err, graph.ErrInvalidFundingOutput)
 
 		case <-time.After(2 * time.Second):
 			t.Fatalf("remote announcement not processed")
@@ -4221,11 +4214,11 @@ func TestChanAnnBanningNonChanPeer(t *testing.T) {
 
 	// Set the error to ErrChannelSpent so that we can test that the
 	// gossiper ignores closed channels.
-	ctx.router.setAddEdgeErrCode(graph.ErrChannelSpent)
+	ctx.router.setAddEdgeErr(graph.ErrChannelSpent)
 
 	select {
 	case err = <-ctx.gossiper.ProcessRemoteAnnouncement(ca, nodePeer2):
-		require.True(t, graph.IsError(err, graph.ErrChannelSpent))
+		require.ErrorIs(t, err, graph.ErrChannelSpent)
 
 	case <-time.After(2 * time.Second):
 		t.Fatalf("remote announcement not processed")
@@ -4248,7 +4241,7 @@ func TestChanAnnBanningNonChanPeer(t *testing.T) {
 
 	// Reset the AddEdge error and pass the same announcement again. An
 	// error should be returned even though AddEdge won't fail.
-	ctx.router.resetAddEdgeErrCode()
+	ctx.router.resetAddEdgeErr()
 
 	select {
 	case err = <-ctx.gossiper.ProcessRemoteAnnouncement(ca, nodePeer2):
@@ -4269,7 +4262,7 @@ func TestChanAnnBanningChanPeer(t *testing.T) {
 
 	nodePeer := &mockPeer{remoteKeyPriv1.PubKey(), nil, nil, atomic.Bool{}}
 
-	ctx.router.setAddEdgeErrCode(graph.ErrInvalidFundingOutput)
+	ctx.router.setAddEdgeErr(graph.ErrInvalidFundingOutput)
 
 	// Loop 100 times to get nodePeer banned.
 	for i := 0; i < 100; i++ {
@@ -4283,11 +4276,7 @@ func TestChanAnnBanningChanPeer(t *testing.T) {
 		case err = <-ctx.gossiper.ProcessRemoteAnnouncement(
 			ca, nodePeer,
 		):
-			require.True(
-				t, graph.IsError(
-					err, graph.ErrInvalidFundingOutput,
-				),
-			)
+			require.ErrorIs(t, err, graph.ErrInvalidFundingOutput)
 
 		case <-time.After(2 * time.Second):
 			t.Fatalf("remote announcement not processed")