fix: audio transcription only charge for the length of audio duration

common/helper/audio_test.go

@@ -0,0 +1,37 @@
+package helper
+
+import (
+	"context"
+	"io"
+	"net/http"
+	"os"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestGetAudioDuration(t *testing.T) {
+	t.Run("should return correct duration for a valid audio file", func(t *testing.T) {
+		tmpFile, err := os.CreateTemp("", "test_audio*.mp3")
+		require.NoError(t, err)
+		defer os.Remove(tmpFile.Name())
+
+		// download test audio file
+		resp, err := http.Get("https://s3.laisky.com/uploads/2025/01/audio-sample.m4a")
+		require.NoError(t, err)
+		defer resp.Body.Close()
+
+		_, err = io.Copy(tmpFile, resp.Body)
+		require.NoError(t, err)
+		require.NoError(t, tmpFile.Close())
+
+		duration, err := GetAudioDuration(context.Background(), tmpFile.Name())
+		require.NoError(t, err)
+		require.Equal(t, duration, 3.904)
+	})
+
+	t.Run("should return an error for a non-existent file", func(t *testing.T) {
+		_, err := GetAudioDuration(context.Background(), "non_existent_file.mp3")
+		require.Error(t, err)
+	})
+}