test_appsync.py

import json
import pathlib
import pytest

from aws_lambda_powertools.utilities.parser import parse, ValidationError
from aws_lambda_powertools.utilities.parser.models.appsync import AppSyncResolverEventModel


def load_event(filename: str) -> dict:
    """
    Load a JSON event from the events directory.

    The function navigates four levels up from the current file to locate the
    `tests/events` folder.
    """
    event_path = pathlib.Path(__file__).parent.parent.parent.parent / "events" / filename
    with event_path.open() as f:
        return json.load(f)


def test_appsync_event_model_parses_successfully():
    """
    Validate that a valid AppSync resolver event is correctly parsed by the model.
    """
    event = load_event("appsync_resolver_event.json")

    parsed_event = parse(event=event, model=AppSyncResolverEventModel)

    assert parsed_event.arguments["page"] == 2
    assert parsed_event.identity.username == "mike"
    assert parsed_event.request.headers["host"].endswith("appsync-api.us-east-1.amazonaws.com")
    assert parsed_event.info.fieldName == "locations"
    assert parsed_event.info.parentTypeName == "Merchant"


def test_appsync_event_model_invalid_payload_raises():
    """
    Validate that parsing an invalid AppSync resolver event payload raises a ValidationError.
    """
    invalid_event = {"invalid": "event"}

    with pytest.raises(ValidationError):
        parse(event=invalid_event, model=AppSyncResolverEventModel)