Amazon web services – Converting to CDK version2 leading to test cases being failed

I converted my cdk infrastructure code from version 1 to version 2. It was a successful conversion.

However, some of the test cases are now being failed. I haven’t touched any other code except changing references from version to version 2.

Possible causes :- The infrastructure uses apigatewayv2, apigatewayv2-integrations, apigatewayv2-authorizers ( alpha version of these packages)

Since i have not written code, i cannot help you with development code.
However i can provide the code where test cases are being failed.

Package for lambda is being used as @types/aws-lambda https://www.npmjs.com/package/@types/aws-lambda

import { BookDetailUseCaseInput } from '@use-cases/suken-account/detail-book'
import { IsString, Length, Matches, MinLength } from 'class-validator'
import { APIGatewayProxyEvent } from 'aws-lambda'

readonly bookId: string
  @IsString({
    message: 'wdawdawd。',
  })
  @MinLength(1, {
    message: 'wdawd。',
  })
  readonly token: string

  @IsString({
    message: 'wdawd。',
  })
  @MinLength(1, {
    message: 'dwdada',
  })
  readonly appVersion: string

  constructor(event: APIGatewayProxyEvent) {
    this.bookId = event.pathParameters!.book_id
    this.token = event.headers.authorization?.split('Bearer')[1]?.trimLeft()
    this.appVersion = event.headers['app-viewer-version']
  }

error message during test run

  35     this.token = event.headers.authorization?.split('Bearer')[1]?.trimLeft()
           ~~~~~~~~~~
    src/modules/validators/wdwdwd-account/wdwdwdwd-request.ts:36:5 - error TS2322: Type 'string | undefined' is not assignable to type 'string'.
      Type 'undefined' is not assignable to type 'string'.

    36     this.appVersion = event.headers['app-viewer-version']

I think APIGatewayProxyEvent is sending values in different format in cdk version 2