Fixed `DeprecationWarning` for `PromptTemplate.from_file` module-level calls (#14468)

Resolves https://github.com/langchain-ai/langchain/issues/14467

libs/langchain/langchain/chains/llm_summarization_checker/base.py

@@ -17,18 +17,10 @@ from langchain.chains.sequential import SequentialChain
 
 PROMPTS_DIR = Path(__file__).parent / "prompts"
 
-CREATE_ASSERTIONS_PROMPT = PromptTemplate.from_file(
-    PROMPTS_DIR / "create_facts.txt", ["summary"]
-)
-CHECK_ASSERTIONS_PROMPT = PromptTemplate.from_file(
-    PROMPTS_DIR / "check_facts.txt", ["assertions"]
-)
-REVISED_SUMMARY_PROMPT = PromptTemplate.from_file(
-    PROMPTS_DIR / "revise_summary.txt", ["checked_assertions", "summary"]
-)
-ARE_ALL_TRUE_PROMPT = PromptTemplate.from_file(
-    PROMPTS_DIR / "are_all_true_prompt.txt", ["checked_assertions"]
-)
+CREATE_ASSERTIONS_PROMPT = PromptTemplate.from_file(PROMPTS_DIR / "create_facts.txt")
+CHECK_ASSERTIONS_PROMPT = PromptTemplate.from_file(PROMPTS_DIR / "check_facts.txt")
+REVISED_SUMMARY_PROMPT = PromptTemplate.from_file(PROMPTS_DIR / "revise_summary.txt")
+ARE_ALL_TRUE_PROMPT = PromptTemplate.from_file(PROMPTS_DIR / "are_all_true_prompt.txt")
 
 
 def _load_sequential_chain(

libs/langchain/tests/unit_tests/chains/test_llm_summarization_checker.py

@@ -14,6 +14,13 @@ from langchain.chains.llm_summarization_checker.base import (
 from tests.unit_tests.llms.fake_llm import FakeLLM
 
 
+def test_input_variables() -> None:
+    assert CREATE_ASSERTIONS_PROMPT.input_variables == ["summary"]
+    assert CHECK_ASSERTIONS_PROMPT.input_variables == ["assertions"]
+    assert REVISED_SUMMARY_PROMPT.input_variables == ["checked_assertions", "summary"]
+    assert ARE_ALL_TRUE_PROMPT.input_variables == ["checked_assertions"]
+
+
 @pytest.fixture
 def fake_llm_summarization_checker_chain() -> LLMSummarizationCheckerChain:
     """Fake LLMCheckerChain for testing."""