test_prompt.py — langchain Source File

Source Code

"""Test functionality related to prompts."""

import re
from tempfile import NamedTemporaryFile
from typing import Any, Literal
from unittest import mock

import pytest
from packaging import version
from syrupy.assertion import SnapshotAssertion

from langchain_core.prompts.prompt import PromptTemplate
from langchain_core.prompts.string import PromptTemplateFormat
from langchain_core.tracers.run_collector import RunCollectorCallbackHandler
from langchain_core.utils.pydantic import PYDANTIC_VERSION
from tests.unit_tests.pydantic_utils import _normalize_schema

PYDANTIC_VERSION_AT_LEAST_29 = version.parse("2.9") <= PYDANTIC_VERSION


def test_prompt_valid() -> None:
    """Test prompts can be constructed."""
    template = "This is a {foo} test."
    input_variables = ["foo"]
    prompt = PromptTemplate(input_variables=input_variables, template=template)
    assert prompt.template == template
    assert prompt.input_variables == input_variables


def test_from_file_encoding() -> None:
    """Test that we can load a template from a file with a non utf-8 encoding."""
    template = "This is a {foo} test with special character €."
    input_variables = ["foo"]

    # First write to a file using CP-1252 encoding.
    with NamedTemporaryFile(delete=True, mode="w", encoding="cp1252") as f:
        f.write(template)
        f.flush()
        file_name = f.name

        # Now read from the file using CP-1252 encoding and test
        prompt = PromptTemplate.from_file(file_name, encoding="cp1252")
        assert prompt.template == template
        assert prompt.input_variables == input_variables

        # Now read from the file using UTF-8 encoding and test
        with pytest.raises(UnicodeDecodeError):
            PromptTemplate.from_file(file_name, encoding="utf-8")


def test_prompt_from_template() -> None:
    """Test prompts can be constructed from a template."""
    # Single input variable.
    template = "This is a {foo} test."
    prompt = PromptTemplate.from_template(template)
    expected_prompt = PromptTemplate(template=template, input_variables=["foo"])
    assert prompt == expected_prompt

    # Multiple input variables.
    template = "This {bar} is a {foo} test."
// ... (671 more lines)