How to resolve AWS CDK error "Argument of type 'Function' is not assignable to parameter of type 'IFunction'"

Question

I want to get the following example code from https://docs.aws.amazon.com/cdk/latest/guide/serverless_example.html working, but I get a "Argument of type 'Function' is not assignable to parameter of type 'IFunction'" error.

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

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

    const handler = new lambda.Function(this, 'WidgetHandler', {
      runtime: lambda.Runtime.NODEJS_10_X, // So we can use async in widget.js
      code: lambda.Code.fromAsset('resources'),
      handler: 'widgets.main',
    });

    const api = new apigateway.RestApi(this, 'widgets-api', {
      restApiName: 'Widget Service',
      description: 'This service serves widgets.',
    });

    const getWidgetsIntegration = new apigateway.LambdaIntegration(handler, {
      requestTemplates: { 'application/json': '{ "statusCode": "200" }' },
    });

    api.root.addMethod('GET', getWidgetsIntegration); // GET /
  }
}

The full error below seems to indicate that at least part of the issue migh be that the aws-apigateway package has its own packages that are incompatible.

I am lost as to how to resolve this, so any help is much appreciated.

test-deploy/ApiGatewayFunctionStack.ts:49:68 - error TS2345: Argument of type 'Function' is not assignable to parameter of type 'IFunction'.
  Types of property 'role' are incompatible.
    Type 'import("D:/Users/andyb/Documents/github/agb-aws-functions/node_modules/@aws-cdk/aws-iam/lib/role").IRole | undefined' is not assignable to type 'import("D:/Users/andyb/Documents/github/agb-aws-functions/node_modules/@aws-cdk/aws-apigateway/node_modules/@aws-cdk/aws-iam/lib/role").IRole | undefined'.
      Type 'import("D:/Users/andyb/Documents/github/agb-aws-functions/node_modules/@aws-cdk/aws-iam/lib/role").IRole' is not assignable to type 'import("D:/Users/andyb/Documents/github/agb-aws-functions/node_modules/@aws-cdk/aws-apigateway/node_modules/@aws-cdk/aws-iam/lib/role").IRole'.
        Types of property 'grant' are incompatible.
          Type '(grantee: import("D:/Users/andyb/Documents/github/agb-aws-functions/node_modules/@aws-cdk/aws-iam/lib/principals").IPrincipal, ...actions: string[]) => import("D:/Users/andyb/Documents/github/agb-aws-functions/node_modules/@aws-cdk/aws-iam/lib/grant").Grant' is not assignable to type '(grantee: import("D:/Users/andyb/Documents/github/agb-aws-functions/node_modules/@aws-cdk/aws-apigateway/node_modules/@aws-cdk/aws-iam/lib/principals").IPrincipal, ...actions: string[]) => import("D:/Users/andyb/Documents/github/agb-aws-functions/node_modules/@aws-cdk/aws-apigateway/node_modules/@aws-cdk/aws-iam/lib...'.
            Types of parameters 'grantee' and 'grantee' are incompatible.
              Type 'import("D:/Users/andyb/Documents/github/agb-aws-functions/node_modules/@aws-cdk/aws-apigateway/node_modules/@aws-cdk/aws-iam/lib/principals").IPrincipal' is not assignable to type 'import("D:/Users/andyb/Documents/github/agb-aws-functions/node_modules/@aws-cdk/aws-iam/lib/principals").IPrincipal'.
                Types of property 'addToPolicy' are incompatible.
                  Type '(statement: import("D:/Users/andyb/Documents/github/agb-aws-functions/node_modules/@aws-cdk/aws-apigateway/node_modules/@aws-cdk/aws-iam/lib/policy-statement").PolicyStatement) => boolean' is not assignable to type '(statement: import("D:/Users/andyb/Documents/github/agb-aws-functions/node_modules/@aws-cdk/aws-iam/lib/policy-statement").PolicyStatement) => boolean'.
                    Types of parameters 'statement' and 'statement' are incompatible.
                      Type 'import("D:/Users/andyb/Documents/github/agb-aws-functions/node_modules/@aws-cdk/aws-iam/lib/policy-statement").PolicyStatement' is not assignable to type 'import("D:/Users/andyb/Documents/github/agb-aws-functions/node_modules/@aws-cdk/aws-apigateway/node_modules/@aws-cdk/aws-iam/lib/policy-statement").PolicyStatement'.
                        Types have separate declarations of a private property 'action'.

49     const getWidgetsIntegration = new apigateway.LambdaIntegration(handler, {

Answer 1

This error Argument of type 'SomeClass' is not assignable to parameter of type 'ISomeClass' typically occurs when version of CDK dependencies are at different versions. To solve the issue, we need to bring all the dependencies to same version.

• Delete node_modules folder
• Delete package-lock.json
• Ensure all dependencies in package.json are using same version.
• Remove carrot ^ symbol before dependencies for example from "@aws-cdk/aws-lambda": "^1.90.0" to "@aws-cdk/aws-lambda": "1.90.0" , to avoid different minor versions getting installed.
• npm install