routing+lnd: prepare closed channel SCIDs in server

The method `FetchClosedChannels` sometimes prematurely mark a pending
force closing channel as finalized, therefore we need to furthur check
`FetchPendingChannels` to make sure the channel is indeed finalized.

routing/router_test.go

@@ -93,9 +93,7 @@ func (c *testCtx) getChannelIDFromAlias(t *testing.T, a, b string) uint64 {
 	return channelID
 }
 
-func mockFetchClosedChannels(_ bool) ([]*channeldb.ChannelCloseSummary, error) {
-	return nil, nil
-}
+var mockClosedSCIDs map[lnwire.ShortChannelID]struct{}
 
 func createTestCtxFromGraphInstance(t *testing.T, startingHeight uint32,
 	graphInstance *testGraphInstance) *testCtx {
@@ -162,10 +160,10 @@ func createTestCtxFromGraphInstanceAssumeValid(t *testing.T,
 			next := atomic.AddUint64(&uniquePaymentID, 1)
 			return next, nil
 		},
-		PathFindingConfig:   pathFindingConfig,
-		Clock:               clock.NewTestClock(time.Unix(1, 0)),
-		ApplyChannelUpdate:  graphBuilder.ApplyChannelUpdate,
-		FetchClosedChannels: mockFetchClosedChannels,
+		PathFindingConfig:  pathFindingConfig,
+		Clock:              clock.NewTestClock(time.Unix(1, 0)),
+		ApplyChannelUpdate: graphBuilder.ApplyChannelUpdate,
+		ClosedSCIDs:        mockClosedSCIDs,
 	})
 	require.NoError(t, router.Start(), "unable to start router")
 
@@ -2175,7 +2173,7 @@ func TestSendToRouteSkipTempErrSuccess(t *testing.T) {
 		NextPaymentID: func() (uint64, error) {
 			return 0, nil
 		},
-		FetchClosedChannels: mockFetchClosedChannels,
+		ClosedSCIDs: mockClosedSCIDs,
 	}}
 
 	// Register mockers with the expected method calls.
@@ -2259,7 +2257,7 @@ func TestSendToRouteSkipTempErrNonMPP(t *testing.T) {
 		NextPaymentID: func() (uint64, error) {
 			return 0, nil
 		},
-		FetchClosedChannels: mockFetchClosedChannels,
+		ClosedSCIDs: mockClosedSCIDs,
 	}}
 
 	// Expect an error to be returned.
@@ -2314,7 +2312,7 @@ func TestSendToRouteSkipTempErrTempFailure(t *testing.T) {
 		NextPaymentID: func() (uint64, error) {
 			return 0, nil
 		},
-		FetchClosedChannels: mockFetchClosedChannels,
+		ClosedSCIDs: mockClosedSCIDs,
 	}}
 
 	// Create the error to be returned.
@@ -2397,7 +2395,7 @@ func TestSendToRouteSkipTempErrPermanentFailure(t *testing.T) {
 		NextPaymentID: func() (uint64, error) {
 			return 0, nil
 		},
-		FetchClosedChannels: mockFetchClosedChannels,
+		ClosedSCIDs: mockClosedSCIDs,
 	}}
 
 	// Create the error to be returned.
@@ -2484,7 +2482,7 @@ func TestSendToRouteTempFailure(t *testing.T) {
 		NextPaymentID: func() (uint64, error) {
 			return 0, nil
 		},
-		FetchClosedChannels: mockFetchClosedChannels,
+		ClosedSCIDs: mockClosedSCIDs,
 	}}
 
 	// Create the error to be returned.