fix(runtime): bound tenant resource amplification

tests/unit_tests/pipeline/test_longtext_image.py

@@ -1,6 +1,11 @@
+from types import SimpleNamespace
 from unittest.mock import Mock
 
+import pytest
+
+import langbot_plugin.api.entities.builtin.platform.message as platform_message
 from langbot.pkg.pipeline.longtext.strategies.image import Text2ImageStrategy
+from langbot.pkg.pipeline.longtext.strategies import image
 
 
 class _WideFont:
@@ -15,3 +20,31 @@ def test_image_strategy_line_split_always_consumes_input():
 
     assert lines == ['a', 'b', 'c']
     assert ''.join(lines) == 'abc'
+
+
+def test_image_strategy_numeric_boundaries_are_found_in_linear_order():
+    strategy = Text2ImageStrategy(Mock())
+
+    assert strategy.indexNumber('a12-b12-c345') == [['12', 1], ['12', 5], ['345', 9]]
+
+
+def test_image_strategy_rejects_unbounded_line_count_before_allocating_canvas(monkeypatch):
+    strategy = Text2ImageStrategy(Mock())
+    monkeypatch.setattr(image, '_MAX_TEXT_TO_IMAGE_LINES', 2)
+
+    with pytest.raises(ValueError, match='2 lines'):
+        strategy._split_text_lines('one\ntwo\nthree', 1000, _WideFont())
+
+
+@pytest.mark.asyncio
+async def test_image_strategy_falls_back_to_forward_for_oversized_text(monkeypatch):
+    app = Mock()
+    strategy = Text2ImageStrategy(app)
+    monkeypatch.setattr(image, '_MAX_TEXT_TO_IMAGE_CHARS', 4)
+    query = SimpleNamespace(adapter=SimpleNamespace(bot_account_id='bot'))
+
+    components = await strategy.process('12345', query)
+
+    assert len(components) == 1
+    assert isinstance(components[0], platform_message.Forward)
+    app.logger.warning.assert_called_once()