Write backfills json even if no backfills to process (#5209)

Author: ANich

bigquery_etl/cli/backfill.py

@@ -310,7 +310,7 @@ def scheduled(ctx, qualified_table_name, sql_dir, project_id, status, json_path=
 
     click.echo(f"{len(backfills)} backfill(s) require processing.")
 
-    if backfills and json_path is not None:
+    if json_path is not None:
         formatted_backfills = [
             {
                 "qualified_table_name": qualified_table_name,

tests/cli/test_cli_backfill.py

@@ -1,3 +1,4 @@
+import json
 import os
 from datetime import date, timedelta
 from pathlib import Path
@@ -1830,6 +1831,7 @@ def test_backfill_scheduled(self, get_table, runner):
             assert result.exit_code == 0
             assert "1 backfill(s) require processing." in result.output
             assert Path("tmp.json").exists()
+            assert len(json.loads(Path("tmp.json").read_text())) == 1
 
             result = runner.invoke(
                 scheduled,