some changes:

- added unit tests
    - put all subcmds into one file
    - use io.Writer for output, better for testing

api/db_test.go

@@ -0,0 +1,59 @@
+/*
+Copyright © 2023 Thomas von Dein
+
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program. If not, see <http://www.gnu.org/licenses/>.
+*/
+
+package api
+
+import (
+	"github.com/tlinden/cenophane/cfg"
+	"os"
+	"testing"
+)
+
+func finalize(db *Db) {
+	if db.bolt != nil {
+		db.Close()
+	}
+	if _, err := os.Stat(db.cfg.DbFile); err == nil {
+		os.Remove(db.cfg.DbFile)
+	}
+}
+
+func TestNew(t *testing.T) {
+	var tests = []struct {
+		name     string
+		file     string
+		wantfail bool
+	}{
+		{"opennew", "test.db", false},
+		{"openfail", "/hopefully/not/existing/directory/test.db", true},
+	}
+
+	for _, tt := range tests {
+		c := &cfg.Config{DbFile: tt.file}
+		t.Run(tt.name, func(t *testing.T) {
+			db, err := NewDb(c)
+			defer finalize(db)
+			if err != nil && !tt.wantfail {
+				t.Errorf("expected: &Db{}, got err: " + err.Error())
+			}
+
+			if err == nil && tt.wantfail {
+				t.Errorf("expected: fail, got &Db{}")
+			}
+		})
+	}
+}