How Do You Implement VPC Peering with AWS CDK?

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

// Define your VPCs
const vpc1 = new ec2.Vpc(this, 'Vpc1', { 
  maxAzs: 2,
  cidr: '10.0.0.0/16' 
});

const vpc2 = new ec2.Vpc(this, 'Vpc2', { 
  maxAzs: 2,
  cidr: '10.1.0.0/16' // Ensure CIDRs do not overlap
});

// Create the peering connection
// vpc1 is the 'Requester', vpc2 is the 'Accepter'
const peeringConnection = vpc1.peer(vpc2, {
  peeringConnectionName: 'Vpc1-to-Vpc2-Peering'
});

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

new ec2.CfnVPCPeeringConnection(this, 'CustomPeering', {
  vpcId: 'vpc-xxxxxx',       // Requester VPC ID
  peerVpcId: 'vpc-yyyyyy',   // Accepter VPC ID
  peerRegion: 'us-east-1',   // Optional: if peering across regions
  peerOwnerId: '123456789012' // Optional: if peering across accounts
});

import * as cdk from 'aws-cdk-lib';
import { Template, Match } from 'aws-cdk-lib/assertions';
import * as MyStack from '../lib/my-stack'; // Import your stack definition

test('VPC Peering Connection Created', () => {
  const app = new cdk.App();
  // INSTANTIATE YOUR STACK HERE
  const stack = new MyStack.MyPeeringStack(app, 'MyTestStack');
  
  // Create a template from the stack
  const template = Template.fromStack(stack);

  // 1. Assert that the Peering Connection resource exists
  template.resourceCountIs('AWS::EC2::VPCPeeringConnection', 1);

  // 2. Assert that the Route Tables have a route to the peering connection
  // We check for a route that points to a "VpcPeeringConnectionId"
  template.hasResourceProperties('AWS::EC2::Route', {
    VpcPeeringConnectionId: {
      Ref: Match.stringLikeRegexp('^VpcPeering.*') // Matches the logical ID
    }
  });
  
  // 3. Verify the Peering is between the correct VPCs (Optional specific check)
  // This ensures the "PeerVpcId" property is present
  template.hasResourceProperties('AWS::EC2::VPCPeeringConnection', {
     VpcId: Match.anyValue(),
     PeerVpcId: Match.anyValue()
  });
});