go(algo/util): add createFolder func

algo/util.go

@@ -3,8 +3,28 @@
 
 package algo
 
-import "strings"
+import (
+	"errors"
+	"log"
+	"os"
+	"strings"
+)
 
 func sanitiseFName(s string) string {
 	return strings.ReplaceAll(s, " ", "_")
 }
+
+// createFolder creates a folder at the specified path, if it doesn't already
+// exist.
+func createFolder(path string) error {
+	var err error
+
+	if _, err = os.Stat(path); errors.Is(err, os.ErrNotExist) {
+		err = os.Mkdir(path, os.ModePerm)
+		if err != nil {
+			log.Println(err)
+		}
+	}
+
+	return err
+}

algo/util_test.go

@@ -0,0 +1,24 @@
+// Copyright 2022 wanderer <a_mirre at utb dot cz>
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+package algo
+
+import (
+	"os"
+	"testing"
+)
+
+// nolint: ifshort
+func TestCreateFolder(t *testing.T) {
+	// let's assume this will never exist in a clean project...
+	testPath := "whatever-path"
+	got := createFolder(testPath)
+
+	var want error
+
+	if want != got {
+		t.Errorf("issue creating folder: got %q", got.Error())
+	}
+
+	os.RemoveAll(testPath)
+}