graph/db: skip TestGraphLoading for non-bbolt store

Let all the NewTestDB functions return the V1Store interface type
instead of pointers. Then add a manual skip in the TestGraphLoading test
for any non-bbolt backend. We can remove this once all the methods used
by the test have been implemented by the SQLStore. We only need the
manual skip for this one test since it is the only one that doesnt use
MakeGraphTest to init the graph db.

graph/db/graph_test.go

@@ -4232,6 +4232,15 @@ func TestGraphLoading(t *testing.T) {
 	// Next, create the graph for the first time.
 	graphStore := NewTestDB(t)
 
+	// Temporarily add a manual skip for this test, until all the methods
+	// it uses have been implemented on the SQLStore struct. We have to
+	// manually add this skip because it is the only test that doesn't use
+	// the MakeTestGraph helper to create the graph store.
+	_, ok := graphStore.(*KVStore)
+	if !ok {
+		t.Skipf("Skipping TestGraphLoading for non-bbolt graph store")
+	}
+
 	graph, err := NewChannelGraph(graphStore)
 	require.NoError(t, err)
 	require.NoError(t, graph.Start())

graph/db/test_kvdb.go

@@ -10,7 +10,7 @@ import (
 )
 
 // NewTestDB is a helper function that creates an BBolt database for testing.
-func NewTestDB(t testing.TB) *KVStore {
+func NewTestDB(t testing.TB) V1Store {
 	backend, backendCleanup, err := kvdb.GetTestBackend(t.TempDir(), "cgr")
 	require.NoError(t, err)
 

graph/db/test_postgres.go

@@ -14,7 +14,7 @@ import (
 // NewTestDB is a helper function that creates a SQLStore backed by a postgres
 // database for testing. At the moment, it embeds a KVStore but once the
 // SQLStore fully implements the V1Store interface, the KVStore will be removed.
-func NewTestDB(t testing.TB) *SQLStore {
+func NewTestDB(t testing.TB) V1Store {
 	backend, backendCleanup, err := kvdb.GetTestBackend(t.TempDir(), "cgr")
 	require.NoError(t, err)
 

graph/db/test_sqlite.go

@@ -14,7 +14,7 @@ import (
 // NewTestDB is a helper function that creates a SQLStore backed by a sqlite
 // database for testing. At the moment, it embeds a KVStore but once the
 // SQLStore fully implements the V1Store interface, the KVStore will be removed.
-func NewTestDB(t testing.TB) *SQLStore {
+func NewTestDB(t testing.TB) V1Store {
 	backend, backendCleanup, err := kvdb.GetTestBackend(t.TempDir(), "cgr")
 	require.NoError(t, err)