Move get picture to a utils package so it can be reused

notification/service_telegram.go

@@ -4,11 +4,11 @@ import (
 	"bytes"
 	"fmt"
 	"os"
-	"path/filepath"
 	"strconv"
 	"text/template"
 
 	"git.ctrlz.es/mgdelacroix/birthdaybot/model"
+	"git.ctrlz.es/mgdelacroix/birthdaybot/utils"
 	"github.com/charmbracelet/log"
 	tgbotapi "github.com/go-telegram-bot-api/telegram-bot-api/v5"
 )
@@ -39,18 +39,6 @@ func NewTelegramNotificationService(logger *log.Logger, config *model.Config) (*
 	}, nil
 }
 
-func (tns *TelegramNotificationService) getPictureFileForBirthday(birthday *model.Birthday) (string, error) {
-	filename := birthday.Filename()
-	path := filepath.Join(tns.config.Birthdays.Pictures, filename)
-
-	_, err := os.Stat(path)
-	if err != nil {
-		return "", err
-	}
-
-	return path, nil
-}
-
 func (tns *TelegramNotificationService) Notify(birthday *model.Birthday, template *template.Template) error {
 	var msgText string
 	if template != nil {
@@ -69,7 +57,7 @@ func (tns *TelegramNotificationService) Notify(birthday *model.Birthday, templat
 		return fmt.Errorf("cannot parse ChannelID: %w", err)
 	}
 
-	picture, err := tns.getPictureFileForBirthday(birthday)
+	picture, err := utils.GetPictureForBirthday(birthday, tns.config.Birthdays.Pictures)
 	if err != nil && !os.IsNotExist(err) {
 		return fmt.Errorf("cannot get picture for birthday: %w", err)
 	}

utils/utils.go

@@ -0,0 +1,20 @@
+package utils
+
+import (
+	"os"
+	"path/filepath"
+
+	"git.ctrlz.es/mgdelacroix/birthdaybot/model"
+)
+
+func GetPictureForBirthday(birthday *model.Birthday, picturesDir string) (string, error) {
+	filename := birthday.Filename()
+	path := filepath.Join(picturesDir, filename)
+
+	_, err := os.Stat(path)
+	if err != nil {
+		return "", err
+	}
+
+	return path, nil
+}

utils/utils_test.go

@@ -0,0 +1,47 @@
+package utils
+
+import (
+	"os"
+	"path/filepath"
+	"testing"
+
+	"git.ctrlz.es/mgdelacroix/birthdaybot/model"
+	"github.com/stretchr/testify/require"
+)
+
+// ToDo: replace with os.CreateTemp
+// ioutil.TempFile()
+func TestGetPictureForBirthday(t *testing.T) {
+	tmpDir, err := os.MkdirTemp("", "birthdaybot-pictures-")
+	require.NoError(t, err)
+	defer os.RemoveAll(tmpDir)
+
+	birthday := &model.Birthday{
+		Name:         "John Doe",
+		Email:        "john@doe.com",
+		Phone:        "987654321",
+		YearOfBirth:  2022,
+		MonthOfBirth: 7,
+		DayOfBirth:   1,
+	}
+
+	expectedPath := filepath.Join(tmpDir, "2022_7_1_987654321.png")
+
+	t.Run("should return the right path when the file exists", func(t *testing.T) {
+		// we create the file
+		require.NoError(t, os.WriteFile(expectedPath, []byte("dummy"), 0755))
+
+		picture, err := GetPictureForBirthday(birthday, tmpDir)
+		require.NoError(t, err)
+		require.Equal(t, expectedPath, picture)
+	})
+
+	t.Run("should fail if the file doesn't exist", func(t *testing.T) {
+		// we ensure that the file doesn't exist
+		require.NoError(t, os.Remove(expectedPath))
+
+		picture, err := GetPictureForBirthday(birthday, tmpDir)
+		require.ErrorIs(t, err, os.ErrNotExist)
+		require.Empty(t, picture)
+	})
+}