Provide feedback if no files or statements found (#32)

Provide feedback if no migration files were found

migrate/migrate.go

@@ -78,6 +78,9 @@ func Migrate(ctx context.Context, session *gocql.Session, dir string) error {
 	if err != nil {
 		return fmt.Errorf("failed to list migrations in %q: %s", dir, err)
 	}
+	if len(fm) == 0 {
+		return fmt.Errorf("no migration files found in %q", dir)
+	}
 	sort.Strings(fm)
 
 	// verify migrations
@@ -149,6 +152,7 @@ func applyMigration(ctx context.Context, session *gocql.Session, path string, do
 	defer iq.Release()
 
 	i := 1
+	stmtCount := 0
 	r := bytes.NewBuffer(b)
 	for {
 		stmt, err := r.ReadString(';')
@@ -158,6 +162,8 @@ func applyMigration(ctx context.Context, session *gocql.Session, path string, do
 		if err != nil {
 			return err
 		}
+		stmtCount++
+
 		if i <= done {
 			i++
 			continue
@@ -178,6 +184,9 @@ func applyMigration(ctx context.Context, session *gocql.Session, path string, do
 
 		i++
 	}
+	if stmtCount == 0 {
+		return fmt.Errorf("no migration statements found in %q", info.Name)
+	}
 
 	return nil
 }