Allow checkpoints for empty audio accepted by WhisperX

internal/app/transcribe_checkpoint_recovery_test.go

@@ -18,6 +18,57 @@ import (
 	"gitea.maximumdirect.net/eric/narratio/internal/stage"
 )
 
+func TestExecuteStagesDelegatesEmptyAudioAcceptanceToWhisperX(t *testing.T) {
+	for _, rejected := range []bool{false, true} {
+		name := "accepted"
+		if rejected {
+			name = "rejected"
+		}
+		t.Run(name, func(t *testing.T) {
+			cfg, store := setupTranscribeRecoveryFixture(t, []string{"alice"})
+			paths := artifacts.NewLocalStore(cfg.Pipeline.Workspace.Root).SessionPathsFor(cfg.Session.Campaign, cfg.Session.SessionID)
+			if err := os.WriteFile(filepath.Join(paths.AudioDir, "alice.flac"), nil, 0o644); err != nil {
+				t.Fatal(err)
+			}
+			fake := &whisperx.FakeClient{}
+			if rejected {
+				fake.Err = errors.New("service rejected audio")
+			}
+			transcribe := mustSelectStage(t, "transcribe")
+			_, err := executeStages(context.Background(), cfg, []stage.Stage{transcribe}, RunOptions{
+				Env: &Env{ManifestStore: store, WhisperX: fake},
+			})
+			if !errors.Is(err, fake.Err) {
+				t.Fatalf("transcribe error = %v, want %v", err, fake.Err)
+			}
+			if len(fake.RequestsSnapshot()) != 1 {
+				t.Fatal("empty audio was not sent to service")
+			}
+			m := loadTranscribeRecoveryManifest(t, store, cfg)
+			if rejected {
+				if len(m.Stages["transcribe"].TranscribeSpeakers) != 0 {
+					t.Fatal("rejected audio was checkpointed")
+				}
+				return
+			}
+			record, ok := m.Stages["transcribe"].TranscribeSpeakers["alice"]
+			if !ok || record.AudioSize != 0 {
+				t.Fatalf("missing zero-size checkpoint: %#v", record)
+			}
+			retry := &whisperx.FakeClient{}
+			summary, err := executeStages(context.Background(), cfg, []stage.Stage{transcribe}, RunOptions{
+				Env: &Env{ManifestStore: store, WhisperX: retry},
+			})
+			if err != nil {
+				t.Fatal(err)
+			}
+			if len(summary.Skipped) != 1 || len(retry.RequestsSnapshot()) != 0 {
+				t.Fatal("successful empty-audio result was not reused")
+			}
+		})
+	}
+}
+
 func TestExecuteStagesRetriesOnlyUncommittedTranscribeSpeakers(t *testing.T) {
 	cfg, baseStore := setupTranscribeRecoveryFixture(t, []string{"a", "b", "c", "d"})
 	concurrency := 1

internal/manifest/transcribe_state.go

@@ -92,8 +92,8 @@ func validateTranscribeSpeakerRecord(speakerID string, record TranscribeSpeakerR
 	if err := validateSHA256("audio_sha256", record.AudioSHA256); err != nil {
 		return err
 	}
-	if record.AudioSize <= 0 {
-		return fmt.Errorf("audio_size must be positive")
+	if record.AudioSize < 0 {
+		return fmt.Errorf("audio_size must not be negative")
 	}
 	if record.Output.Kind != "transcript_raw" {
 		return fmt.Errorf("output kind %q must be transcript_raw", record.Output.Kind)

internal/manifest/transcribe_state_test.go

@@ -12,6 +12,8 @@ import (
 func TestTranscribeSpeakerStateRoundTripsPopulatedAndVersionedEmptyCollections(t *testing.T) {
 	now := time.Date(2026, 9, 21, 12, 0, 0, 0, time.UTC)
 	store := &LocalStore{}
+	zeroAudio := validTranscribeSpeakerRecord("Alice Table 1")
+	zeroAudio.AudioSize = 0
 
 	for _, test := range []struct {
 		name    string
@@ -24,6 +26,7 @@ func TestTranscribeSpeakerStateRoundTripsPopulatedAndVersionedEmptyCollections(t
 			},
 		},
 		{name: "versioned empty", records: map[string]TranscribeSpeakerRecord{}},
+		{name: "zero size audio", records: map[string]TranscribeSpeakerRecord{"Alice Table 1": zeroAudio}},
 	} {
 		t.Run(test.name, func(t *testing.T) {
 			m := New("session", now)
@@ -49,6 +52,9 @@ func TestTranscribeSpeakerStateRoundTripsPopulatedAndVersionedEmptyCollections(t
 			}
 			if len(test.records) != 0 {
 				got := stage.TranscribeSpeakers["Alice Table 1"]
+				if got.AudioSize != test.records["Alice Table 1"].AudioSize {
+					t.Fatalf("audio size = %d, want %d", got.AudioSize, test.records["Alice Table 1"].AudioSize)
+				}
 				if got.AudioPath != "inputs/audio/Alice Table 1.flac" || got.Output.LocalPath != "transcripts/raw/Alice Table 1.json" {
 					t.Fatalf("round-tripped record = %#v", got)
 				}
@@ -99,7 +105,7 @@ func TestValidateTranscribeSpeakerCollectionRejectsMalformedEvidence(t *testing.
 		{name: "unsafe audio path", speakerID: "alice", mutate: func(r *TranscribeSpeakerRecord) { r.AudioPath = "../alice.flac" }, want: "audio_path is unsafe"},
 		{name: "noncanonical audio path", speakerID: "alice", mutate: func(r *TranscribeSpeakerRecord) { r.AudioPath = "inputs/audio/../alice.flac" }, want: "not canonical"},
 		{name: "bad audio checksum", speakerID: "alice", mutate: func(r *TranscribeSpeakerRecord) { r.AudioSHA256 = strings.Repeat("G", 64) }, want: "audio_sha256 must be"},
-		{name: "bad audio size", speakerID: "alice", mutate: func(r *TranscribeSpeakerRecord) { r.AudioSize = 0 }, want: "audio_size must be positive"},
+		{name: "negative audio size", speakerID: "alice", mutate: func(r *TranscribeSpeakerRecord) { r.AudioSize = -1 }, want: "audio_size"},
 		{name: "bad output kind", speakerID: "alice", mutate: func(r *TranscribeSpeakerRecord) { r.Output.Kind = "transcript" }, want: "must be transcript_raw"},
 		{name: "unsafe output path", speakerID: "alice", mutate: func(r *TranscribeSpeakerRecord) { r.Output.LocalPath = "/tmp/alice.json" }, want: "output local_path is unsafe"},
 		{name: "bad output checksum", speakerID: "alice", mutate: func(r *TranscribeSpeakerRecord) { r.Output.Checksum = "bad" }, want: "output checksum must be"},