fix(template-transform): use base64 encoding for Jinja2 templates to fix #26818 (#30223)

Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>
Co-authored-by: crazywoola <100913391+crazywoola@users.noreply.github.com>

api/core/helper/code_executor/jinja2/jinja2_transformer.py

@@ -1,9 +1,14 @@
+from collections.abc import Mapping
 from textwrap import dedent
+from typing import Any
 
 from core.helper.code_executor.template_transformer import TemplateTransformer
 
 
 class Jinja2TemplateTransformer(TemplateTransformer):
+    # Use separate placeholder for base64-encoded template to avoid confusion
+    _template_b64_placeholder: str = "{{template_b64}}"
+
     @classmethod
     def transform_response(cls, response: str):
         """
@@ -13,18 +18,35 @@ class Jinja2TemplateTransformer(TemplateTransformer):
         """
         return {"result": cls.extract_result_str_from_response(response)}
 
+    @classmethod
+    def assemble_runner_script(cls, code: str, inputs: Mapping[str, Any]) -> str:
+        """
+        Override base class to use base64 encoding for template code.
+        This prevents issues with special characters (quotes, newlines) in templates
+        breaking the generated Python script. Fixes #26818.
+        """
+        script = cls.get_runner_script()
+        # Encode template as base64 to safely embed any content including quotes
+        code_b64 = cls.serialize_code(code)
+        script = script.replace(cls._template_b64_placeholder, code_b64)
+        inputs_str = cls.serialize_inputs(inputs)
+        script = script.replace(cls._inputs_placeholder, inputs_str)
+        return script
+
     @classmethod
     def get_runner_script(cls) -> str:
         runner_script = dedent(f"""
-            # declare main function
-            def main(**inputs):
-                import jinja2
-                template = jinja2.Template('''{cls._code_placeholder}''')
-                return template.render(**inputs)
-
+            import jinja2
             import json
             from base64 import b64decode
 
+            # declare main function
+            def main(**inputs):
+                # Decode base64-encoded template to handle special characters safely
+                template_code = b64decode('{cls._template_b64_placeholder}').decode('utf-8')
+                template = jinja2.Template(template_code)
+                return template.render(**inputs)
+
             # decode and prepare input dict
             inputs_obj = json.loads(b64decode('{cls._inputs_placeholder}').decode('utf-8'))
 

api/core/helper/code_executor/template_transformer.py

@@ -13,6 +13,15 @@ class TemplateTransformer(ABC):
     _inputs_placeholder: str = "{{inputs}}"
     _result_tag: str = "<<RESULT>>"
 
+    @classmethod
+    def serialize_code(cls, code: str) -> str:
+        """
+        Serialize template code to base64 to safely embed in generated script.
+        This prevents issues with special characters like quotes breaking the script.
+        """
+        code_bytes = code.encode("utf-8")
+        return b64encode(code_bytes).decode("utf-8")
+
     @classmethod
     def transform_caller(cls, code: str, inputs: Mapping[str, Any]) -> tuple[str, str]:
         """