Added some db unit tests

backend/internal/test/suite.go

@@ -0,0 +1,23 @@
+package test
+
+import (
+	"npm/internal/database"
+
+	"github.com/DATA-DOG/go-sqlmock"
+	"gorm.io/driver/postgres"
+	"gorm.io/gorm"
+)
+
+func Setup() (sqlmock.Sqlmock, error) {
+	db, mock, err := sqlmock.New()
+	if err != nil {
+		return nil, err
+	}
+	dialector := postgres.New(postgres.Config{
+		Conn:       db,
+		DriverName: "postgres",
+	})
+	gormDB, err := gorm.Open(dialector, &gorm.Config{})
+	database.SetDB(gormDB)
+	return mock, err
+}