fix(pgsql): return subquery preload errors instead of logging and continuing

pkg/common/adapters/database/pgsql.go

@@ -1208,7 +1208,7 @@ func (p *PgSQLSelectQuery) applySubqueryPreloads(ctx context.Context, dest inter
 		for i := 0; i < destValue.Len(); i++ {
 			elem := destValue.Index(i)
 			if err := p.loadPreloadsForRecord(ctx, elem, subqueryPreloads); err != nil {
-				logger.Warn("Failed to load preloads for record %d: %v", i, err)
+				return fmt.Errorf("record %d: %w", i, err)
 			}
 		}
 		return nil
@@ -1256,7 +1256,9 @@ func (p *PgSQLSelectQuery) loadPreloadsForRecord(ctx context.Context, record ref
 		// Build and execute the preload query
 		err := p.executePreloadQuery(ctx, field, meta, fkValue, preload)
 		if err != nil {
-			logger.Warn("Failed to execute preload query for '%s': %v", preload.relation, err)
+			// Inside a transaction a failed statement aborts it, so carrying on would
+			// only turn into a misleading "transaction is aborted" on the next query.
+			return fmt.Errorf("preload %s: %w", preload.relation, err)
 		}
 	}
 

pkg/common/adapters/database/pgsql_preload_test.go

@@ -0,0 +1,56 @@
+package database
+
+import (
+	"context"
+	"errors"
+	"strings"
+	"testing"
+
+	"github.com/DATA-DOG/go-sqlmock"
+
+	"github.com/bitechdev/ResolveSpec/pkg/common"
+)
+
+type preloadChild struct {
+	ID     int `db:"id"`
+	UserID int `db:"user_id"`
+}
+
+func (preloadChild) TableName() string { return "children" }
+
+type preloadParent struct {
+	ID       int            `db:"id"`
+	Children []preloadChild `bun:"rel:has-many,join:ID=user_id"`
+}
+
+func (preloadParent) TableName() string { return "parents" }
+
+func TestSubqueryPreloadErrorIsReturned(t *testing.T) {
+	for name, dest := range map[string]interface{}{
+		"slice":  &[]preloadParent{},
+		"single": &preloadParent{},
+	} {
+		t.Run(name, func(t *testing.T) {
+			db, mock, err := sqlmock.New()
+			if err != nil {
+				t.Fatal(err)
+			}
+			defer db.Close()
+
+			mock.ExpectBegin()
+			mock.ExpectQuery(`FROM parents`).WillReturnRows(sqlmock.NewRows([]string{"id"}).AddRow(1))
+			mock.ExpectQuery(`FROM children`).WillReturnError(errors.New("boom"))
+			mock.ExpectRollback()
+
+			err = NewPgSQLAdapter(db).RunInTransaction(context.Background(), func(tx common.Database) error {
+				return tx.NewSelect().Model(&preloadParent{}).PreloadRelation("Children").Scan(context.Background(), dest)
+			})
+			if err == nil || !strings.Contains(err.Error(), "preload Children") {
+				t.Fatalf("expected the preload error, got %v", err)
+			}
+			if err := mock.ExpectationsWereMet(); err != nil {
+				t.Fatal(err)
+			}
+		})
+	}
+}