home-services/tts-gateway/internal/app/tts_test.go

package app

import (
	"context"
	"errors"
	"testing"

	"gitea.nik4nao.com/nik/home-services/tts-gateway/internal/core/domain"
)

type mockNormalizer struct {
	normalizeFunc func(ctx context.Context, text string) ([]int64, error)
}

func (m *mockNormalizer) Normalize(ctx context.Context, text string) ([]int64, error) {
	return m.normalizeFunc(ctx, text)
}

type mockEngine struct {
	synthesizeFunc func(ctx context.Context, speakerID int, symbolIDs []int64, params domain.SynthesisParams) ([]float32, int, error)
}

func (m *mockEngine) Synthesize(ctx context.Context, speakerID int, symbolIDs []int64, params domain.SynthesisParams) ([]float32, int, error) {
	return m.synthesizeFunc(ctx, speakerID, symbolIDs, params)
}

type mockEncoder struct {
	encodeFunc func(ctx context.Context, pcm []float32, sampleRate int) ([]byte, string, error)
}

func (m *mockEncoder) Encode(ctx context.Context, pcm []float32, sampleRate int) ([]byte, string, error) {
	return m.encodeFunc(ctx, pcm, sampleRate)
}

func TestTTSAppSynthesize(t *testing.T) {
	t.Run("unknown speaker returns ErrSpeakerNotFound without calling downstream ports", func(t *testing.T) {
		a := NewTTSApp(
			&mockNormalizer{normalizeFunc: func(context.Context, string) ([]int64, error) {
				t.Fatal("Normalize should not be called for an unknown speaker")
				return nil, nil
			}},
			&mockEngine{},
			&mockEncoder{},
		)

		_, err := a.Synthesize(context.Background(), "Not A Real Speaker", "hello", domain.SynthesisParams{})
		if !errors.Is(err, ErrSpeakerNotFound) {
			t.Fatalf("Synthesize() error = %v, want %v", err, ErrSpeakerNotFound)
		}
	})

	t.Run("happy path wires normalize -> engine -> encode", func(t *testing.T) {
		wantParams := domain.SynthesisParams{NoiseScale: 0.1, NoiseScaleW: 0.2, LengthScale: 0.3}
		wantSymbolIDs := []int64{1, 2, 3}
		wantPCM := []float32{0.5, -0.5}
		wantSampleRate := 22050
		wantAudio := []byte{1, 2, 3, 4}
		wantMimeType := "audio/aac"

		a := NewTTSApp(
			&mockNormalizer{normalizeFunc: func(_ context.Context, text string) ([]int64, error) {
				if text != "hello" {
					t.Fatalf("Normalize() text = %q, want %q", text, "hello")
				}
				return wantSymbolIDs, nil
			}},
			&mockEngine{synthesizeFunc: func(_ context.Context, speakerID int, symbolIDs []int64, params domain.SynthesisParams) ([]float32, int, error) {
				if speakerID != 29 {
					t.Fatalf("Synthesize() speakerID = %d, want 29 (Rice Shower)", speakerID)
				}
				if len(symbolIDs) != len(wantSymbolIDs) {
					t.Fatalf("Synthesize() symbolIDs = %v, want %v", symbolIDs, wantSymbolIDs)
				}
				if params != wantParams {
					t.Fatalf("Synthesize() params = %v, want %v", params, wantParams)
				}
				return wantPCM, wantSampleRate, nil
			}},
			&mockEncoder{encodeFunc: func(_ context.Context, pcm []float32, sampleRate int) ([]byte, string, error) {
				if sampleRate != wantSampleRate {
					t.Fatalf("Encode() sampleRate = %d, want %d", sampleRate, wantSampleRate)
				}
				return wantAudio, wantMimeType, nil
			}},
		)

		got, err := a.Synthesize(context.Background(), "Rice Shower", "hello", wantParams)
		if err != nil {
			t.Fatalf("Synthesize() error = %v", err)
		}
		if string(got.Data) != string(wantAudio) || got.MimeType != wantMimeType {
			t.Fatalf("Synthesize() = %+v, want Data=%v MimeType=%q", got, wantAudio, wantMimeType)
		}
	})

	t.Run("propagates normalizer error", func(t *testing.T) {
		wantErr := errors.New("normalize failed")
		a := NewTTSApp(
			&mockNormalizer{normalizeFunc: func(context.Context, string) ([]int64, error) { return nil, wantErr }},
			&mockEngine{},
			&mockEncoder{},
		)

		_, err := a.Synthesize(context.Background(), "Rice Shower", "hello", domain.SynthesisParams{})
		if !errors.Is(err, wantErr) {
			t.Fatalf("Synthesize() error = %v, want %v", err, wantErr)
		}
	})
}

func TestTTSAppListSpeakers(t *testing.T) {
	a := NewTTSApp(&mockNormalizer{}, &mockEngine{}, &mockEncoder{})

	t.Run("empty search returns full roster", func(t *testing.T) {
		got := a.ListSpeakers(context.Background(), "")
		if len(got) != len(domain.Speakers) {
			t.Fatalf("ListSpeakers(\"\") returned %d names, want %d", len(got), len(domain.Speakers))
		}
	})

	t.Run("case-insensitive substring filter", func(t *testing.T) {
		got := a.ListSpeakers(context.Background(), "rice")
		if len(got) != 1 || got[0] != "Rice Shower" {
			t.Fatalf("ListSpeakers(\"rice\") = %v, want [\"Rice Shower\"]", got)
		}
	})

	t.Run("no match returns empty, not nil roster", func(t *testing.T) {
		got := a.ListSpeakers(context.Background(), "definitely not a speaker")
		if len(got) != 0 {
			t.Fatalf("ListSpeakers() = %v, want empty", got)
		}
	})
}