test: FailUpload must not overwrite a finished upload; ffmpeg stderr is bounded, red (review of #55)

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

internal/adapters/store/uploaded_transcripts_failguard_test.go

@@ -0,0 +1,47 @@
+package store_test
+
+// A shutdown can record a job as failed after its transcript was already committed (the
+// commit lands, the caller sees a cancelled context). FailUpload must not be able to turn a
+// finished row into a failed one and hide the text (#50 review).
+
+import (
+	"context"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+
+	"git.d-ma.be/mathias/tapir/internal/domain"
+)
+
+func TestFailUpload_LeavesAFinishedUploadAsItWas(t *testing.T) {
+	s := newStore(t)
+	ctx := context.Background()
+	id := startedUpload(t, s)
+	require.NoError(t, s.StartTranscribing(ctx, userA, id))
+	require.NoError(t, s.CompleteUpload(ctx, userA, id, domain.Transcription{Text: "synthetic text", Endpoint: "iguana/kb-whisper"}))
+
+	_ = s.FailUpload(ctx, userA, id, domain.UploadErrInterrupted)
+
+	got, err := s.GetUpload(ctx, userA, id)
+	require.NoError(t, err)
+	assert.Equal(t, domain.UploadDone, got.Status)
+	assert.Equal(t, "synthetic text", got.Content)
+	assert.Empty(t, got.ErrorKind)
+}
+
+func TestFailUpload_StillFailsAQueuedOrTranscribingUpload(t *testing.T) {
+	s := newStore(t)
+	ctx := context.Background()
+	queued := startedUpload(t, s)
+	running, err := s.CreateUpload(ctx, userA, "r", false)
+	require.NoError(t, err)
+	require.NoError(t, s.StartTranscribing(ctx, userA, running))
+
+	for _, id := range []string{queued, running} {
+		require.NoError(t, s.FailUpload(ctx, userA, id, domain.UploadErrBusy))
+		got, err := s.GetUpload(ctx, userA, id)
+		require.NoError(t, err)
+		assert.Equal(t, domain.UploadFailed, got.Status)
+	}
+}