fix(updater): fix update summary with up-to-date configuration

src/ops2deb/updater.py

@@ -231,7 +231,7 @@ def update(
                 for r in latest_releases
                 if r.is_new
             ]
-            output_path.write_text("\n".join(lines) + "\n")
+            output_path.write_text("\n".join(lines + [""]))
 
     _, fetcher_errors = separate_successes_from_errors(fetch_results.values())
     if fetcher_errors or updater_errors:

tests/test_ops2deb.py

@@ -39,6 +39,21 @@
     - mv great-app {{src}}/usr/bin/great-app
 """
 
+mock_configuration_up_to_date = """\
+- name: great-app
+  version: 1.1.1
+  revision: 2
+  arch: all
+  summary: Great package
+  description: A detailed description of the great package.
+  fetch:
+    url: http://testserver/{{version}}/great-app.tar.gz
+    sha256: f1be6dd36b503641d633765655e81cdae1ff8f7f73a2582b7468adceb5e212a9
+  script:
+    - mv great-app {{src}}/usr/bin/great-app
+"""
+
+
 mock_configuration_with_invalid_archive_checksum = """\
 - name: bad-app
   version: 1.0.0
@@ -276,6 +291,32 @@ def test_ops2deb_update_should_succeed_with_valid_configuration(tmp_path, call_o
     assert configuration[0].fetch.sha256 == sha256
 
 
+def test_ops2deb_update_should_create_summary_when_called_with_output_file(
+    tmp_path, call_ops2deb
+):
+    output_file = tmp_path / "summary.log"
+    call_ops2deb(
+        "update",
+        "--output-file",
+        str(output_file),
+        configuration=mock_configuration_with_invalid_archive_checksum,
+    )
+    assert output_file.read_text() == "Updated bad-app from 1.0.0 to 1.1.1\n"
+
+
+def test_ops2deb_update_should_create_empty_summary_when_called_with_output_file_and_config_is_up_to_date(  # noqa: E501
+    tmp_path, call_ops2deb
+):
+    output_file = tmp_path / "summary.log"
+    call_ops2deb(
+        "update",
+        "--output-file",
+        str(output_file),
+        configuration=mock_configuration_up_to_date,
+    )
+    assert output_file.read_text() == ""
+
+
 def test_ops2deb_update_should_succeed_with_single_blueprint_configuration(
     tmp_path, call_ops2deb
 ):