AWS Lamda Handler Type

[makmashuk]

Hey, we are migrating aws sdk to v3 but for lamda handler we couldn't find any type inside @aws-sdk/client-lambda package, Are you planning to add the handler types inside the package or we need to use @types/aws-lambda?

[aungkhantkyaw9]

I am also have the same issue. In v2 there are types for aws-lambda. But in v3, could not find any type related to AWS Lambda functions

[dmoskovtsov]

Example for v2:

Can anyone please provide information on the expected way of typing it in v3? (using "@aws-sdk/client-lambda": "3.476.0")

export const apiV2Handler: APIGatewayProxyHandler = async (event, context) => {
    return {
        body: 'Response body',
        statusCode: 200
    }
}

[RanVaknin]

Hi everyone on the thread.

Can you highlight specific imports that are missing from v3 but existed in v2? A complete code sample with imports would be ideal.

Thanks,
Ran~

[makmashuk]

Hey , Please check the below block

import { Handler } from 'aws-lambda';

export const handler: Handler = async (event, context) => {
    console.log('EVENT: \n' + JSON.stringify(event, null, 2));
    return context.logStreamName;
};

import { Context, APIGatewayProxyCallback, APIGatewayEvent } from 'aws-lambda';

export const lambdaHandler = (event: APIGatewayEvent, context: Context, callback: APIGatewayProxyCallback): void => {
    console.log(`Event: ${JSON.stringify(event, null, 2)}`);
    console.log(`Context: ${JSON.stringify(context, null, 2)}`);
    callback(null, {
        statusCode: 200,
        body: JSON.stringify({
            message: 'hello world',
        }),
    });
};

currently we were using this package(https://github.com/DefinitelyTyped/DefinitelyTyped/tree/master/types/aws-lambda) for AWS SDK v2

[RanVaknin]

Thanks for the context.

I just want to highlight that aws-lambda is an independent 3rd party package that is not maintained by AWS. As far as I can tell, it's not scoped to the v2 SDK, and does not seem to be related to any SDK for that matter, this is just a library of types.

Neither v2, nor v3 offer type definitions for writing Lambda functions. The type definitions the official AWS SDK @aws-sdk/client-lambda offers is for the Lambda's control plane API, which means the types generated are for provisioning, updating, deleting and invoking functions, and not for writing the lambda code itself.

Unlike https://github.com/aws/aws-lambda-go, which is an official package managed by the Lambda team on AWS, there is no JS equivalent I am aware of, therefore I cannot make recommendations about this.

If this has worked for you in v2, I don't see a reason why this would not work on v3, as this is independent from the AWS SDK offering.

Thanks,
Ran~

[couimet]

Hello @RanVaknin !

Now that close to 6 months has passed, I wanted to validate that the above answer is still valid.

AWS is still not providing types definitions for writing lambda code itself ?

Given that https://aws.amazon.com/blogs/developer/first-class-typescript-support-in-modular-aws-sdk-for-javascript/ is titled First-class TypeScript support in modular AWS SDK for JavaScript, I was somewhat expecting that AWS would provide an equivalent of https://github.com/DefinitelyTyped/DefinitelyTyped/tree/master/types/aws-lambda so we do not need to rely on a 3rd party as the source of the TypeScript types ?