fix(db): stop writing a column that does not exist when editing an observation (#69)

UpdateObservation set updated_at_epoch, but the observations table has no such column, so every PUT /api/observations/{id} failed with HTTP 500 (no such column: updated_at_epoch). Remove the assignment; nothing reads an edited-at time. An update that changes nothing now returns the observation, as intended. UpdateObservation had no tests: add store and handler tests.

Co-authored-by: Claude Sonnet 5.5 <[email protected]>

internal/db/gorm/observation_store.go

@@ -252,9 +252,6 @@ func (s *ObservationStore) UpdateObservation(ctx context.Context, id int64, upda
 		updates["scope"] = sql.NullString{String: *update.Scope, Valid: true}
 	}
 
-	// Add updated_at timestamp
-	updates["updated_at_epoch"] = sql.NullInt64{Int64: time.Now().Unix(), Valid: true}
-
 	if len(updates) == 0 {
 		// Nothing to update, just return existing observation
 		return toModelObservation(&dbObs), nil

internal/db/gorm/observation_update_test.go

@@ -0,0 +1,94 @@
+package gorm
+
+import (
+	"context"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+
+	"github.com/lukaszraczylo/claude-mnemonic/pkg/models"
+)
+
+func storeForUpdate(t *testing.T) (*ObservationStore, int64, func()) {
+	t.Helper()
+	obsStore, store, cleanup := testObservationStore(t)
+	ctx := context.Background()
+	sessionID, err := NewSessionStore(store).CreateSDKSession(ctx, "claude-1", "test-project", "")
+	require.NoError(t, err)
+	id, _, err := obsStore.StoreObservation(ctx, "claude-1", "test-project", &models.ParsedObservation{
+		Type: models.ObsTypeDiscovery, Title: "Original title", Subtitle: "Original subtitle", Narrative: "Original narrative",
+		Facts: []string{"fact one"}, Concepts: []string{"cache"}, FilesRead: []string{"a.go"},
+	}, int(sessionID), 1)
+	require.NoError(t, err)
+	return obsStore, id, cleanup
+}
+
+func ptr[T any](v T) *T { return &v }
+
+func TestUpdateObservation_ChangesOnlyTheGivenFields(t *testing.T) {
+	obsStore, id, cleanup := storeForUpdate(t)
+	defer cleanup()
+	ctx := context.Background()
+
+	got, err := obsStore.UpdateObservation(ctx, id, &ObservationUpdate{Title: ptr("New title"), Narrative: ptr("New narrative")})
+	require.NoError(t, err)
+	assert.Equal(t, "New title", got.Title.String)
+	assert.Equal(t, "New narrative", got.Narrative.String)
+	assert.Equal(t, "Original subtitle", got.Subtitle.String, "a field that was not given stays")
+	assert.Equal(t, []string{"fact one"}, []string(got.Facts))
+
+	stored, err := obsStore.GetObservationByID(ctx, id)
+	require.NoError(t, err)
+	assert.Equal(t, "New title", stored.Title.String, "and it is stored, not only returned")
+}
+
+func TestUpdateObservation_ReplacesListsAndScope(t *testing.T) {
+	obsStore, id, cleanup := storeForUpdate(t)
+	defer cleanup()
+	ctx := context.Background()
+
+	got, err := obsStore.UpdateObservation(ctx, id, &ObservationUpdate{
+		Facts: &[]string{"a", "b"}, Concepts: &[]string{}, FilesRead: &[]string{"x.go"}, FilesModified: &[]string{"y.go"}, Scope: ptr("global"),
+	})
+	require.NoError(t, err)
+	assert.Equal(t, []string{"a", "b"}, []string(got.Facts))
+	assert.Empty(t, got.Concepts, "an empty list clears the field")
+	assert.Equal(t, []string{"x.go"}, []string(got.FilesRead))
+	assert.Equal(t, []string{"y.go"}, []string(got.FilesModified))
+	assert.Equal(t, models.ScopeGlobal, got.Scope)
+}
+
+func TestUpdateObservation_NothingToChangeReturnsTheObservation(t *testing.T) {
+	obsStore, id, cleanup := storeForUpdate(t)
+	defer cleanup()
+
+	got, err := obsStore.UpdateObservation(context.Background(), id, &ObservationUpdate{})
+	require.NoError(t, err)
+	assert.Equal(t, "Original title", got.Title.String)
+}
+
+func TestUpdateObservation_Refusals(t *testing.T) {
+	obsStore, id, cleanup := storeForUpdate(t)
+	defer cleanup()
+	ctx := context.Background()
+
+	_, err := obsStore.UpdateObservation(ctx, id, nil)
+	assert.Error(t, err, "a nil update")
+	_, err = obsStore.UpdateObservation(ctx, 999999, &ObservationUpdate{Title: ptr("x")})
+	require.Error(t, err)
+	assert.Contains(t, err.Error(), "not found")
+}
+
+func TestUpdateObservation_KeepsTheSearchIndexInStep(t *testing.T) {
+	obsStore, id, cleanup := storeForUpdate(t)
+	defer cleanup()
+	ctx := context.Background()
+
+	_, err := obsStore.UpdateObservation(ctx, id, &ObservationUpdate{Title: ptr("Zebrafish enclosure")})
+	require.NoError(t, err)
+	var n int64
+	require.NoError(t, obsStore.db.WithContext(ctx).Raw(
+		`SELECT COUNT(*) FROM observations_fts WHERE observations_fts MATCH 'zebrafish'`).Scan(&n).Error)
+	assert.EqualValues(t, 1, n, "the full-text index sees the new title")
+}