Add database.go, Rollback()

database.go

@@ -0,0 +1,17 @@
+package abutil
+
+import (
+	"database/sql"
+)
+
+// Rollback does a rollback on the transaction and returns either the error
+// from the rollback if there was one or the alternative.
+// This is useful if you have multiple statments in a row but don't want to
+// call rollback and check for errors every time.
+func Rollback(tx *sql.Tx, alt error) error {
+	if err := tx.Rollback(); err != nil {
+		return err
+	}
+
+	return alt
+}

database_test.go

@@ -0,0 +1,58 @@
+package abutil
+
+import (
+	"database/sql"
+	"errors"
+	"testing"
+
+	"github.com/DATA-DOG/go-sqlmock"
+)
+
+func mockDBContext(t *testing.T, fn func(*sql.DB)) {
+	db, err := sqlmock.New()
+	if err != nil {
+		t.Error(err)
+	}
+	defer db.Close()
+
+	fn(db)
+}
+
+func TestRollback(t *testing.T) {
+	mockDBContext(t, func(db *sql.DB) {
+		sqlmock.ExpectBegin()
+		sqlmock.ExpectRollback()
+
+		tx, err := db.Begin()
+		if err != nil {
+			t.Error(err)
+		}
+
+		alt := errors.New("Some alternative error")
+		err = Rollback(tx, alt)
+
+		if err != alt {
+			t.Errorf("Expected Rollback to return %v, but got %v", alt, err)
+		}
+	})
+}
+
+func TestRollbackFailing(t *testing.T) {
+	mockDBContext(t, func(db *sql.DB) {
+		rberr := errors.New("Some rollback error")
+
+		sqlmock.ExpectBegin()
+		sqlmock.ExpectRollback().
+			WillReturnError(rberr)
+
+		tx, err := db.Begin()
+		if err != nil {
+			t.Error(err)
+		}
+
+		err = Rollback(tx, errors.New("This should not be used"))
+		if err != rberr {
+			t.Errorf("Expected Rollback to return %v, but got %v", rberr, err)
+		}
+	})
+}