`LangchainLLMWrapper.generate_text` does not reset temperature correctly

[Glinte]

[x] I have checked the documentation and related resources and couldn't resolve my bug.

Describe the bug
Both LangchainLLMWrapper.generate_text and LangchainLLMWrapper.agenerate_text sets the inner langchain_llm's temperature to the method's input afterwards

Ragas version: 0.2.15
Python version: 3.13.3

Code to Reproduce

ragas/ragas/src/ragas/llms/base.py

Lines 195 to 233 in 0773595

	def generate_text(
	self,
	prompt: PromptValue,
	n: int = 1,
	temperature: t.Optional[float] = None,
	stop: t.Optional[t.List[str]] = None,
	callbacks: Callbacks = None,
	) -> LLMResult:
	# figure out the temperature to set
	old_temperature: float | None = None
	if temperature is None:
	temperature = self.get_temperature(n=n)
	if hasattr(self.langchain_llm, "temperature"):
	self.langchain_llm.temperature = temperature # type: ignore
	old_temperature = temperature
	if is_multiple_completion_supported(self.langchain_llm):
	result = self.langchain_llm.generate_prompt(
	prompts=[prompt],
	n=n,
	stop=stop,
	callbacks=callbacks,
	)
	else:
	result = self.langchain_llm.generate_prompt(
	prompts=[prompt] * n,
	stop=stop,
	callbacks=callbacks,
	)
	# make LLMResult.generation appear as if it was n_completions
	# note that LLMResult.runs is still a list that represents each run
	generations = [[g[0] for g in result.generations]]
	result.generations = generations
	# reset the temperature to the original value
	if old_temperature is not None:
	self.langchain_llm.temperature = old_temperature # type: ignore
	return result

old_temperature does not actually store the original temperature of the inner langchain_llm, it is storing the result of temperature or self.get_temperature(n=n).

Also, why is self.get_temperature(n=n) used when temperature is None, instead of respecting the setting of langchain_llm and use that instead?

Error trace

Expected behavior
A clear and concise description of what you expected to happen.

Additional context
Add any other context about the problem here.

[anistark]

This issue has been successfully fixed in the current version of Ragas (PR #2295)

Temperature is now properly restored to its original value after method execution. Both generate_text() and agenerate_text() correctly save and restore the original temperature setting.