backend-tasks: no unnecessary janitor log output on sqlite

Signed-off-by: Fredrik Adelöw <freben@gmail.com>

.changeset/nervous-pears-cover.md

@@ -0,0 +1,5 @@
+---
+'@backstage/backend-tasks': patch
+---
+
+Only output janitor logs when actually timing out tasks

packages/backend-tasks/src/tasks/PluginTaskSchedulerJanitor.ts

@@ -62,19 +62,21 @@ export class PluginTaskSchedulerJanitor {
 
     const dbNull = this.knex.raw('null');
 
-    const tasksQuery = this.knex<DbTasksRow>(DB_TASKS_TABLE)
+    const tasks = await this.knex<DbTasksRow>(DB_TASKS_TABLE)
       .where('current_run_expires_at', '<', this.knex.fn.now())
       .update({
         current_run_ticket: dbNull,
         current_run_started_at: dbNull,
         current_run_expires_at: dbNull,
-      });
+      })
+      .returning(['id']);
 
-    if (this.knex.client.config.client === 'sqlite3') {
-      const tasks = await tasksQuery;
-      this.logger.warn(`${tasks} tasks timed out and were lost`);
+    // sqlite ignores "returning", returns number of rows changed instead
+    if (typeof tasks === 'number') {
+      if (tasks > 0) {
+        this.logger.warn(`${tasks} tasks timed out and were lost`);
+      }
     } else {
-      const tasks = await tasksQuery.returning(['id']);
       for (const { id } of tasks) {
         this.logger.warn(`Task timed out and was lost: ${id}`);
       }