Make all json parsing less strict by default (#15287)

- Enables strict=False by default
- Uses partial json recovery logic by default

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libs/core/langchain_core/output_parsers/json.py

@@ -114,7 +114,7 @@ def parse_partial_json(s: str, *, strict: bool = False) -> Any:
 
 
 def parse_json_markdown(
-    json_string: str, *, parser: Callable[[str], Any] = json.loads
+    json_string: str, *, parser: Callable[[str], Any] = parse_partial_json
 ) -> dict:
     """
     Parse a JSON string from a Markdown string.
@@ -190,7 +190,7 @@ class JsonOutputParser(BaseCumulativeTransformOutputParser[Any]):
     def parse(self, text: str) -> Any:
         text = text.strip()
         try:
-            return parse_json_markdown(text.strip(), parser=parse_partial_json)
+            return parse_json_markdown(text.strip())
         except JSONDecodeError as e:
             raise OutputParserException(f"Invalid json output: {text}") from e
 

libs/langchain/langchain/evaluation/parsing/base.py

@@ -1,4 +1,5 @@
 """Evaluators for parsing strings."""
+import json
 from operator import eq
 from typing import Any, Callable, Optional, Union, cast
 
@@ -68,7 +69,7 @@ class JsonValidityEvaluator(StringEvaluator):
 
         """
         try:
-            parse_json_markdown(prediction)
+            parse_json_markdown(prediction, parser=json.loads)
             return {"score": 1}
         except Exception as e:
             return {"score": 0, "reasoning": str(e)}