test_lambda_function_meaningful.py

import boto3
import json
import pytest
from moto import mock_dynamodb2
from lambda_function import *


@pytest.fixture
def test_sqs_event():
    test_sqs_event = {
        "Records": [{
            "body": json.dumps({
                "user_id": "B9B3022F98Fjvjs83AB8/80C185D8",
                "amount": 10 
                "updated_at": "2020-03-03T00:50:47"
            })
        }]}
    return test_sqs_event
    

class MockBotoSession:
    class Session:
        def client(self, service_name, region_name):
            class Client:
                def list_crawlers(self):
                    return {'CrawlerNames': ['crawler_1', 'crawler_2',]}
            return Client()
            

@mock_dynamodb2
@pytest.fixture(autouse=True)
def set_up(monkeypatch):

    dynamodb = boto3.resource('dynamodb', 'us-east-1')

    table = dynamodb.create_table(
        TableName='user_spending',
        KeySchema=[{'AttributeName': 'user_id', 'KeyType': 'HASH'}],
        AttributeDefinitions=[{'AttributeName': 'user_id','AttributeType': 'S'}],
        ProvisionedThroughput={'ReadCapacityUnits': 5, 'WriteCapacityUnits': 5}
    )

    monkeypatch.setattr(boto3, 'session', MockBotoSession)
    yield


def test_lambda_handler(test_sqs_event, set_up):
    
    response = lambda_handler(event=test_sqs_event, context={})

    table = dynamodb.Table(table_name)
    response = table.get_item(
        Key={'user_id': 'B9B3022F98Fjvjs83AB8a80C185D'}
    )
     
    item = response['Item']

    assert item['amount'] == 10
    assert 'updated_at' in item.keys()