CODEWITHSUNDEEP
node.jsaws-cdk
aroe
aroe

Reputation: 519

Argument of type 'this' not assignable to parameter 'Construct'

I am trying to call a lambda function into a 'sample app' stack and it is giving me an error because I am trying to pass it a parameter of 'this'.

Here is my lambda function

export async function handler(event) {
    console.log("request:", JSON.stringify(event, undefined, 2));
    return {
        statusCode: 200,
        headers: { "Content-Type": "text/plain" },
        body: `Hello, CDK! You've hit ${event.path}\n`
    };
};

Here is the 'app' calling that function

//import sns = require('@aws-cdk/aws-sns');
//import subs = require('@aws-cdk/aws-sns-subscriptions');
//import sqs = require('@aws-cdk/aws-sqs');
import cdk = require('@aws-cdk/core');
import lambda = require('@aws-cdk/aws-lambda');

//Exports class from other file much like a function

export class CdkWorkshopStack extends cdk.Stack {
  constructor(scope: cdk.App, id: string, props?: cdk.StackProps) { 
    super(scope, id, props);

    // Describes an AWSLambda Resource
    const hello = new lambda.Function (this, 'HelloHandler', {
      runtime: lambda.Runtime.NODEJS_8_10,    //execution environment
      code: lambda.Code.asset('lambda'),   // code loaded from the "lambda" directory
      handler: 'hello.handler'                // file is "hello", function is "handler"
    });
  }
}

The error I'm getting is:


lib/cdk-workshop-stack.ts:31:39 - error TS2345: Argument of type 'this' is not assignable to parameter of type 'Construct'.
  Type 'CdkWorkshopStack' is not assignable to type 'Construct'.
    Types of property 'node' are incompatible.
      Type 'import("/Users/aroe/cdk-workshop/node_modules/@aws-cdk/core/lib/construct").ConstructNode' is not assignable to type 'import("/Users/aroe/cdk-workshop/node_modules/@aws-cdk/aws-lambda/node_modules/@aws-cdk/core/lib/construct").ConstructNode'.
        Types have separate declarations of a private property 'host'.

31     const hello = new lambda.Function(this, 'HelloHandler', {
                                         ~~~~

[1:24:08 PM] Found 1 error. Watching for file changes.

And finally I am using Node version v13.3.0

Upvotes: 29

Views: 40512

Answers (7)

vikramaditya234
vikramaditya234

Reputation: 1408

This worked for me:

import * as ec2 from 'aws-cdk-lib/aws-ec2';
import * as iam from 'aws-cdk-lib/aws-iam';

instead of using:

import * as ec2 from '@aws-cdk/aws-ec2';
import * as iam from '@aws-cdk/aws-iam';

Getting all the modules from aws-cdk-lib, thus from the same version

Upvotes: 6

lavanya_yaddanapudi
lavanya_yaddanapudi

Reputation: 153

Just changing

import * as cdk from "@aws-cdk/core";

import * as apigw from "@aws-cdk/aws-apigateway";

import lambda from "@aws-cdk/aws-lambda"

import dynamodb from "@aws-cdk/aws-dynamodb"

To

const lambda = require ('@aws-cdk/aws-lambda');

const dynamodb= require('@aws-cdk/aws-dynamodb');

const cdk=require('@aws-cdk/core');

const apigw=require('@aws-cdk/aws-apigateway');

worked for me

Upvotes: 1

Rishabh Jain
Rishabh Jain

Reputation: 49

change import * as cdk from 'aws-cdk-lib';

to import * as cdk from '@aws-cdk/core';

in bin/something_cdk.ts file

Upvotes: 4

Dylan Pierce
Dylan Pierce

Reputation: 4668

In my case I even though I had used the cdk init app --language=typescript the project bootstrapped with the old legacy aws-cdk library.

So when I started using Typescript libraries from the @aws-cdk namespaced packages, I received this error.

So I had to replace all references to Stack, Construct, etc. from the @aws-cdk/core:

import * as cdk from '@aws-cdk/core';
import * as sqs from '@aws-cdk/aws-sqs';
import * as lambda from '@aws-cdk/aws-lambda'
import { SqsEventSource } from '@aws-cdk/aws-lambda-event-sources';

export class WorkerCdkStack extends cdk.Stack {
  constructor(scope: cdk.Construct, id: string, props?: cdk.StackProps) {
    super(scope, id, props);

    // example resource
    const queue = new sqs.Queue(this, 'WorkerQueue', {
      queueName: 'WorkerQueue',
    });

    // processor function
    const processor = new lambda.Function(this, 'QueueProcessor', {
      code: lambda.Code.fromAsset('lambda'),
      handler: 'processor.handler',
      functionName: 'QueueProcessor',
      runtime: lambda.Runtime.NODEJS_12_X,
    });

    // map processor to queue
    processor.addEventSource(new SqsEventSource(queue, {
      batchSize: 10, // default
      reportBatchItemFailures: true, // default to false
    }));
  }
}

Upvotes: 7

Aya Salama
Aya Salama

Reputation: 1518

I got the same error because the installed version for @aws-cdk/aws-lambda and @aws-cdk/aws-sns-subscriptions was different,

while aws-sns-subscriptions has a dependency on aws-lambda of the same version.

enter image description here

when I downgraded @aws-cdk/aws-lambda version the error is gone!

you can also update all aws-cdk packages to have the same version.

Upvotes: 7

Charles Fulton
Charles Fulton

Reputation: 416

The construct definition looks right to me. That error can occur if the various cdk modules aren't all at the same version; see Argument of type 'this' is not assignable to parameter of type 'Construct' for one example of that. Try running npm update; see if that resolves the issue.

Upvotes: 26

aroe
aroe

Reputation: 519

This was solved by simply ignoring the 'this' error and running the lambda anyway. I do not believe it would have worked if it was an actual node/JS program. However, when using CDK native TypeScript it babies you a lot.

Upvotes: 1

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