FIX: Auto Preview of LLM based converters

pyrit/backend/services/converter_service.py

@@ -39,7 +39,7 @@
 from pyrit.models import PromptDataType
 from pyrit.models.data_type_serializer import data_serializer_factory
 from pyrit.prompt_converter import PromptConverter
-from pyrit.prompt_target import PromptChatTarget
+from pyrit.prompt_target import PromptTarget
 from pyrit.registry.object_registries import ConverterRegistry
 
 _DATA_TYPE_EXTENSION: dict[str, str] = {
@@ -184,7 +184,16 @@ def _extract_parameters(converter_class: type) -> list[ConverterParameterSchema]
 
 
 def _is_llm_based(converter_class: type) -> bool:
-    """Return True if the converter requires an LLM target parameter."""
+    """
+    Check if the converter requires a target parameter.
+
+    Matches any converter whose ``__init__`` accepts
+    a ``PromptTarget`` (or subclass) parameter.
+    These converters perform LLM-based transformations and should not automatically be applied
+
+    Returns:
+        bool: True if the converter is LLM-based, False otherwise.
+    """
     try:
         sig = inspect.signature(converter_class.__init__)
     except (ValueError, TypeError):
@@ -197,7 +206,7 @@ def _is_llm_based(converter_class: type) -> bool:
         if ann is inspect.Parameter.empty:
             continue
         try:
-            if isinstance(ann, type) and issubclass(ann, PromptChatTarget):
+            if isinstance(ann, type) and issubclass(ann, PromptTarget):
                 return True
         except TypeError:
             continue

tests/unit/backend/test_converter_service.py

@@ -14,13 +14,20 @@
     ConverterPreviewRequest,
     CreateConverterRequest,
 )
-from pyrit.backend.services.converter_service import ConverterService, get_converter_service
+from pyrit.backend.services.converter_service import ConverterService, _is_llm_based, get_converter_service
 from pyrit.identifiers import ComponentIdentifier
 from pyrit.prompt_converter import (
     Base64Converter,
     CaesarConverter,
+    LLMGenericTextConverter,
+    NoiseConverter,
+    PersuasionConverter,
     RepeatTokenConverter,
     SuffixAppendConverter,
+    TenseConverter,
+    ToneConverter,
+    TranslationConverter,
+    VariationConverter,
 )
 from pyrit.prompt_converter.prompt_converter import get_converter_modalities
 from pyrit.registry.object_registries import ConverterRegistry
@@ -607,3 +614,25 @@ def test_base64_converter_default_params(self) -> None:
         # Verify type info is populated from identifier
         assert isinstance(result.supported_input_types, list)
         assert isinstance(result.supported_output_types, list)
+
+
+class TestIsLlmBased:
+    """Tests for the _is_llm_based introspection helper"""
+
+    def test_detects_llm_text_converter(self) -> None:
+        # Test that _is_llm_based correctly identifies converters that use LLMS as LLM-based.
+        for cls in (
+            LLMGenericTextConverter,
+            NoiseConverter,
+            PersuasionConverter,
+            ToneConverter,
+            TenseConverter,
+            TranslationConverter,
+            VariationConverter,
+        ):
+            assert _is_llm_based(cls) is True, f"{cls.__name__} should be detected as LLM-based"
+
+    def test_does_not_flag_non_target_converters(self) -> None:
+        # Test that _is_llm_based does not incorrectly flag non-LLM converters.
+        assert _is_llm_based(Base64Converter) is False
+        assert _is_llm_based(CaesarConverter) is False