procurement-ingest/tests/conftest.py

"""Shared pytest configuration for the procurement-ingest test suite.

The Lambda handlers create boto3 clients at module import time, so a
region and dummy credentials must be present in the environment before
any handler module is imported. Setting them here at conftest import
time guarantees they exist before test collection touches a handler.
"""

import importlib.util
import os
import sys
from pathlib import Path

import pytest

os.environ.setdefault("AWS_DEFAULT_REGION", "us-east-1")
os.environ.setdefault("AWS_ACCESS_KEY_ID", "testing")
os.environ.setdefault("AWS_SECRET_ACCESS_KEY", "testing")
os.environ.setdefault("AWS_SESSION_TOKEN", "testing")

REPO_ROOT = Path(__file__).resolve().parents[1]


def load_handler(relative_path, module_name):
    """Load a Lambda handler module by file path under a unique name.

    The handler files all share the basename ``handler.py`` and are not
    importable as packages, so a plain ``import handler`` would collide
    across Lambdas. The same loader serves the ``ses_auth.py`` modules,
    which are likewise duplicated per pipeline and not importable as
    packages.

    The Lambda runtime puts each function's own directory on ``sys.path``,
    so handler modules import their siblings by bare name (e.g.
    ``from ses_auth import authenticate_inbound_email``). The function
    directory is added to ``sys.path`` here so the module executes the
    same way under test as it does in the Lambda.
    """
    path = REPO_ROOT / relative_path
    # Put the handler's own directory on sys.path so its sibling-module imports
    # (e.g. the WO handler's ``from template_parser import ...`` and the
    # ``from ses_auth import ...`` in both handlers) resolve.
    handler_dir = str(path.parent)
    if handler_dir not in sys.path:
        sys.path.insert(0, handler_dir)
    spec = importlib.util.spec_from_file_location(module_name, path)
    module = importlib.util.module_from_spec(spec)
    sys.modules[module_name] = module
    spec.loader.exec_module(module)
    return module


@pytest.fixture(scope="session")
def po_handler():
    """The PO email processor handler module."""
    return load_handler(
        "lambdas/po/email_processor/handler.py",
        "po_email_processor_handler",
    )


@pytest.fixture(scope="session")
def wo_handler():
    """The WO email processor handler module."""
    return load_handler(
        "lambdas/wo/email_processor/handler.py",
        "wo_email_processor_handler",
    )


@pytest.fixture(params=["po_handler", "wo_handler"])
def email_handler(request):
    """Parametrized fixture yielding each email processor handler module."""
    return request.getfixturevalue(request.param)


@pytest.fixture(params=["wo", "po"])
def ses_auth(request):
    """The ses_auth module of each pipeline (duplicated file, kept in sync)."""
    pipeline = request.param
    return load_handler(
        f"lambdas/{pipeline}/email_processor/ses_auth.py",
        f"{pipeline}_ses_auth",
    )