Bug: APIGatewayProxyEventSchema incorrect schemas

[blytheaw]

Expected Behavior

Valid API Gateway Proxy request (REST API) with no query string parameters and no body should pass validation when using Powertools Parser and validating against the entire APIGatewayProxyEventSchema

Current Behavior

Valid API Gateway Proxy request (REST API) with no query string parameters and no body is failling validation when using Powertools Parser and validating against the entire APIGatewayProxyEventSchema

Code snippet

import type { Context } from 'aws-lambda';
import type { APIGatewayProxyEvent } from '@aws-lambda-powertools/parser/types';

import { parser } from '@aws-lambda-powertools/parser/middleware';
import { APIGatewayProxyEventSchema } from '@aws-lambda-powertools/parser/schemas';
import middy from '@middy/core';
import { Logger } from '@aws-lambda-powertools/logger';

const logger = new Logger();

const lambdaHandler = async (event: APIGatewayProxyEvent, _context: Context): Promise<void> => {
    logger.info('Event', { event });
};

export const handler = middy(lambdaHandler).use(
  parser({ schema: APIGatewayProxyEventSchema })
);

Steps to Reproduce

1. Create a Lambda handler that uses Powertools Parser middy middleware and passes the default APIGatewayProxyEventSchema from Powertools Parser package as the schema to validate
2. Configure the Lambda as a proxy integration endpoint from API Gateway v1 (REST API)
3. Hit the endpoint with any valid request that doesn't contain query string parameters or a request body
4. Observe Parser/Zod error for invalid fields: queryStringParameters, multiValueQueryStringParameters, and body

Possible Solution

Change the schema to make body, queryStringParameters, and multiValueQueryStringParameters nullable.

This seems to be consistent with @types/aws-lambda and the AWS docs.

These are also the values I have been getting in practice when making actual requests to Lambda and inspecting the event.

I'm happy to submit a PR with these changes if this solution seems reasonable.

Powertools for AWS Lambda (TypeScript) version

2.1.0-beta

AWS Lambda function runtime

18.x

Packaging format used

npm

Execution logs

The parser error


[
  {
    "code": "invalid_type",
    "expected": "object",
    "received": "null",
    "path": [
      "queryStringParameters"
    ],
    "message": "Expected object, received null"
  },
  {
    "code": "invalid_type",
    "expected": "object",
    "received": "null",
    "path": [
      "multiValueQueryStringParameters"
    ],
    "message": "Expected object, received null"
  },
  {
    "code": "invalid_type",
    "expected": "string",
    "received": "null",
    "path": [
      "body"
    ],
    "message": "Expected string, received null"
  }
]

[boring-cyborg]

Thanks for opening your first issue here! We'll come back to you as soon as we can.
In the meantime, check out the #typescript channel on our Powertools for AWS Lambda Discord: Invite link

[dreamorosi]

Hi @blytheaw, thank you for taking the time to try Parser and open an issue.

This is a mistake on our side, these fields should be nullable.

If the offer of opening a PR is still available, I'll take you up on it and help you get the PR merged.

[blytheaw]

@dreamorosi Sure, I'll open a PR. Thanks!