test: started internal/db test cases

- we use github.com/bitcomplete/sqltestutil to spin up a postgresql
container to test against
- minor error variable refactoring

internal/db/db_test.go

@@ -0,0 +1,50 @@
+package db
+
+import (
+	"context"
+	"os"
+	"testing"
+
+	"github.com/bitcomplete/sqltestutil"
+)
+
+var (
+	testDB *DBHandler
+)
+
+func TestMain(m *testing.M) {
+	ctx := context.Background()
+	psql, err := sqltestutil.StartPostgresContainer(ctx, "latest")
+	if err != nil {
+		panic(err)
+	}
+	defer psql.Shutdown(ctx)
+
+	testDB, err = OpenFromConnectionString("postgres", psql.ConnectionString()+"?sslmode=disable")
+	if err != nil {
+		panic(err)
+	}
+	defer testDB.Close()
+
+	if err := testDB.Setup(); err != nil {
+		panic(err)
+	}
+
+	os.Exit(m.Run())
+}
+
+func TestDBAccount(t *testing.T) {
+	if _, err := testDB.NewAccount("test", "test"); err != nil {
+		t.Error(err)
+	}
+
+	// now try to retrieve account data
+	acc, err := testDB.TryLogin("test", "test")
+	if err != nil {
+		t.Error(err)
+	}
+
+	if acc.Login != "test" {
+		t.Error("account username is not test")
+	}
+}