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/account.go

@@ -44,8 +44,8 @@ func (db *DBHandler) NewAccount(Login, Password string) (*Account, error) {
 }
 
 var (
-	LoginErrorInvalidID       = fmt.Errorf("Invalid Login ID!")
-	LoginErrorInvalidPassword = fmt.Errorf("Invalid ID && Password combo!")
+	ErrLoginInvalidID       = fmt.Errorf("invalid Login ID")
+	ErrLoginInvalidPassword = fmt.Errorf("invalid ID && Password combo")
 )
 
 func (db *DBHandler) TryLogin(Login, Password string) (*Account, error) {
@@ -58,11 +58,11 @@ func (db *DBHandler) TryLogin(Login, Password string) (*Account, error) {
 	row.Next()
 	if err := sqlscan.ScanRow(&account, row); err != nil {
 		log.Printf("Error scanning row: %v", err)
-		return nil, LoginErrorInvalidID
+		return nil, ErrLoginInvalidID
 	}
 
 	if bcrypt.CompareHashAndPassword([]byte(account.Password), []byte(Password)) != nil {
-		return nil, LoginErrorInvalidPassword
+		return nil, ErrLoginInvalidPassword
 	}
 
 	// else, login was a success

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")
+	}
+}

internal/db/schema.go

@@ -21,10 +21,8 @@ type DBHandler struct {
 //go:embed migrations/new.sql
 var createDBQuery string
 
-func OpenPostgresDB(dbAddr string) (*DBHandler, error) {
-	fmt := fmt.Sprintf("postgresql://%s:%s@%s/%s?sslmode=disable", config.GetDBUser(), config.GetDBPass(), dbAddr, config.GetDBName())
-
-	db, err := sql.Open("postgres", fmt)
+func OpenFromConnectionString(driverName, connectionString string) (*DBHandler, error) {
+	db, err := sql.Open(driverName, connectionString)
 	if err != nil {
 		return nil, err
 	}
@@ -32,6 +30,11 @@ func OpenPostgresDB(dbAddr string) (*DBHandler, error) {
 	return &DBHandler{db}, nil
 }
 
+func OpenPostgresDB(dbAddr string) (*DBHandler, error) {
+	fmt := fmt.Sprintf("postgresql://%s:%s@%s/%s?sslmode=disable", config.GetDBUser(), config.GetDBPass(), dbAddr, config.GetDBName())
+	return OpenFromConnectionString("postgres", fmt)
+}
+
 func (db *DBHandler) Query(query string, args ...any) (*sql.Rows, error) {
 	return db.db.Query(query, args...)
 }