Use sqlmock with gorm for unit tests

code/go/0chain.net/blobbercore/datastore/mock_store.go

@@ -0,0 +1,32 @@
+package datastore
+
+import (
+	"database/sql"
+	"github.com/DATA-DOG/go-sqlmock"
+	"github.com/stretchr/testify/require"
+	"gorm.io/driver/postgres"
+	"gorm.io/gorm"
+	"testing"
+)
+
+func MockTheStore(t *testing.T) sqlmock.Sqlmock {
+	var db *sql.DB
+	var mock sqlmock.Sqlmock
+	var err error
+	db, mock, err = sqlmock.New()
+	require.NoError(t, err)
+
+	var dialector = postgres.New(postgres.Config{
+		DSN:                  "sqlmock_db_0",
+		DriverName:           "postgres",
+		Conn:                 db,
+		PreferSimpleProtocol: true,
+	})
+	var gdb *gorm.DB
+	gdb, err = gorm.Open(dialector, &gorm.Config{})
+	require.NoError(t, err)
+
+	setDB(gdb)
+
+	return mock
+}

code/go/0chain.net/blobbercore/datastore/store.go

@@ -24,7 +24,7 @@ type Store struct {
 
 var store Store
 
-func SetDB(db *gorm.DB) {
+func setDB(db *gorm.DB) {
 	store.db = db
 }
 

code/go/0chain.net/blobbercore/handler/grpc_handler_test.go

@@ -27,7 +27,6 @@ import (
 	"google.golang.org/grpc/codes"
 	"google.golang.org/grpc/status"
 	"google.golang.org/grpc/test/bufconn"
-	"gorm.io/driver/postgres"
 	"gorm.io/gorm"
 )
 
@@ -103,23 +102,6 @@ func setupServers(t *testing.T) (serverUr string) {
 	return server.URL
 }
 
-func setupDB() sqlmock.Sqlmock {
-	mDB, mock, _ := sqlmock.New()
-	dialector := postgres.New(postgres.Config{
-		DSN:                  "sqlmock_db_0",
-		DriverName:           "postgres",
-		Conn:                 mDB,
-		PreferSimpleProtocol: true,
-	})
-	db, err := gorm.Open(dialector, &gorm.Config{})
-	if err != nil {
-		panic(err)
-	}
-	datastore.SetDB(db)
-
-	return mock
-}
-
 func makeTestClient() (blobbergrpc.BlobberClient, *grpc.ClientConn, error) {
 	var (
 		ctx       = context.Background()
@@ -316,7 +298,7 @@ func Test_GetAllocation(t *testing.T) {
 	for _, test := range tests {
 		t.Run(test.name,
 			func(t *testing.T) {
-				mock := setupDB()
+				var mock = datastore.MockTheStore(t)
 				test.mockSetup(mock)
 				if test.expectCommit {
 					mock.ExpectCommit()