feat: add export app messages (#32990)

api/tests/unit_tests/services/test_export_app_messages.py

@@ -0,0 +1,43 @@
+import datetime
+
+import pytest
+
+from services.retention.conversation.message_export_service import AppMessageExportService
+
+
+def test_validate_export_filename_accepts_relative_path():
+    assert AppMessageExportService.validate_export_filename("exports/2026/test01") == "exports/2026/test01"
+
+
+@pytest.mark.parametrize(
+    "filename",
+    [
+        "test01.jsonl.gz",
+        "test01.jsonl",
+        "test01.gz",
+        "/tmp/test01",
+        "exports/../test01",
+        "bad\x00name",
+        "bad\tname",
+        "a" * 1025,
+    ],
+)
+def test_validate_export_filename_rejects_invalid_values(filename: str):
+    with pytest.raises(ValueError):
+        AppMessageExportService.validate_export_filename(filename)
+
+
+def test_service_derives_output_names_from_filename_base():
+    service = AppMessageExportService(
+        app_id="736b9b03-20f2-4697-91da-8d00f6325900",
+        start_from=None,
+        end_before=datetime.datetime(2026, 3, 1),
+        filename="exports/2026/test01",
+        batch_size=1000,
+        use_cloud_storage=True,
+        dry_run=True,
+    )
+
+    assert service._filename_base == "exports/2026/test01"
+    assert service.output_gz_name == "exports/2026/test01.jsonl.gz"
+    assert service.output_jsonl_name == "exports/2026/test01.jsonl"