1 files changed, 50 insertions, 10 deletions

diff --git a/internal/store/native_tasks.go b/internal/store/native_tasks.go
index 5758407..6f8f999 100644
--- a/internal/store/native_tasks.go
+++ b/internal/store/native_tasks.go
@@ -1,12 +1,21 @@
 package store
 
 import (
+	"database/sql"
 	"encoding/json"
+	"errors"
 	"time"
 
 	"task-dashboard/internal/models"
 )
 
+// ErrNativeTaskNotFound is returned by CompleteNativeTask, UncompleteNativeTask,
+// and RescheduleNativeTask when no row matches the given id -- previously these
+// three silently reported success on a 0-row UPDATE (Exec's err is nil even when
+// no rows match), so a stale or wrong id from a caller looked identical to a real
+// completion: the HTTP response was 200, but nothing in the database changed.
+var ErrNativeTaskNotFound = errors.New("native task not found")
+
 // GetNativeTasks returns all non-completed native tasks.
 func (s *Store) GetNativeTasks() ([]models.Task, error) {
 	rows, err := s.db.Query(`
@@ -71,31 +80,62 @@ func (s *Store) UpdateNativeTask(id, content, description string) error {
 	return err
 }
 
-// CompleteNativeTask marks a task as completed.
+// CompleteNativeTask marks a task as completed. Returns ErrNativeTaskNotFound
+// if id doesn't match any row.
 func (s *Store) CompleteNativeTask(id string) error {
-	_, err := s.db.Exec(`
+	result, err := s.db.Exec(`
 		UPDATE native_tasks SET completed = 1, updated_at = CURRENT_TIMESTAMP WHERE id = ?
 	`, id)
-	return err
+	if err != nil {
+		return err
+	}
+	return checkRowsAffected(result)
 }
 
-// RescheduleNativeTask sets a new due date on a task.
+// RescheduleNativeTask sets a new due date on a task. Returns
+// ErrNativeTaskNotFound if id doesn't match any row.
 func (s *Store) RescheduleNativeTask(id string, dueDate time.Time) error {
-	_, err := s.db.Exec(`
+	result, err := s.db.Exec(`
 		UPDATE native_tasks SET due_date = ?, updated_at = CURRENT_TIMESTAMP WHERE id = ?
 	`, dueDate, id)
-	return err
+	if err != nil {
+		return err
+	}
+	return checkRowsAffected(result)
 }
 
-// UncompleteNativeTask marks a task as not completed.
+// UncompleteNativeTask marks a task as not completed. Returns
+// ErrNativeTaskNotFound if id doesn't match any row.
 func (s *Store) UncompleteNativeTask(id string) error {
-	_, err := s.db.Exec(`
+	result, err := s.db.Exec(`
 		UPDATE native_tasks SET completed = 0, updated_at = CURRENT_TIMESTAMP WHERE id = ?
 	`, id)
-	return err
+	if err != nil {
+		return err
+	}
+	return checkRowsAffected(result)
+}
+
+// checkRowsAffected returns ErrNativeTaskNotFound if the update matched no
+// rows -- mirrors the RowsAffected() check already used in sqlite.go's
+// ApproveAgentSession/DenyAgentSession for the same "silent 0-row update"
+// class of bug.
+func checkRowsAffected(result sql.Result) error {
+	affected, err := result.RowsAffected()
+	if err != nil {
+		return err
+	}
+	if affected == 0 {
+		return ErrNativeTaskNotFound
+	}
+	return nil
 }
 
-func scanNativeTasks(rows interface{ Next() bool; Scan(...interface{}) error; Err() error }) ([]models.Task, error) {
+func scanNativeTasks(rows interface {
+	Next() bool
+	Scan(...interface{}) error
+	Err() error
+}) ([]models.Task, error) {
 	var tasks []models.Task
 	for rows.Next() {
 		var t models.Task