Optimize Amplify App Deployment with Improved Environment Handling an…

…d Code Refactoring

Environment Variable Management: Introduced a helper function, getEnvVar, to streamline environment variable handling, providing clear error messages when required values are missing.
Branch Initialization: Simplified branch setup using .map() to dynamically create branches, reducing code repetition and improving scalability.
Code Organization: Enhanced logical grouping of related sections, making the codebase easier to read and maintain.

packages/@aws-cdk/aws-amplify-alpha/test/integ.app-custom-domain.ts

@@ -1,8 +1,8 @@
+import { App, Stack, StackProps } from 'aws-cdk-lib';
+import { Construct } from 'constructs';
 import * as acm from 'aws-cdk-lib/aws-certificatemanager';
 import * as codecommit from 'aws-cdk-lib/aws-codecommit';
 import * as route53 from 'aws-cdk-lib/aws-route53';
-import { App, Stack, StackProps } from 'aws-cdk-lib';
-import { Construct } from 'constructs';
 import * as amplify from '../lib';
 import { IntegTest } from '@aws-cdk/integ-tests-alpha';
 
@@ -24,8 +24,7 @@ class TestStack extends Stack {
       sourceCodeProvider: new amplify.CodeCommitSourceCodeProvider({ repository }),
     });
 
-    const prodBranch = app.addBranch('main');
-    const devBranch = app.addBranch('dev');
+    const [prodBranch, devBranch] = ['main', 'dev'].map(branchName => app.addBranch(branchName));
 
     const hostedZone = route53.PublicHostedZone.fromHostedZoneAttributes(this, 'HostedZone', {
       hostedZoneId: props.hostedZoneId,
@@ -38,34 +37,24 @@ class TestStack extends Stack {
     });
 
     const domain = app.addDomain(props.domainName, {
-      subDomains: [
-        {
-          branch: prodBranch,
-          prefix: 'prod',
-        },
-      ],
+      subDomains: [{ branch: prodBranch, prefix: 'prod' }],
       customCertificate,
     });
     domain.mapSubDomain(devBranch);
   }
 }
 
-/**
- * In order to test this you need to have a valid public hosted zone that you can use
- * to request certificates for.
-*/
-const hostedZoneId = process.env.CDK_INTEG_HOSTED_ZONE_ID ?? process.env.HOSTED_ZONE_ID;
-if (!hostedZoneId) throw new Error('For this test you must provide your own HostedZoneId as an env var "HOSTED_ZONE_ID". See framework-integ/README.md for details.');
-const hostedZoneName = process.env.CDK_INTEG_HOSTED_ZONE_NAME ?? process.env.HOSTED_ZONE_NAME;
-if (!hostedZoneName) throw new Error('For this test you must provide your own HostedZoneName as an env var "HOSTED_ZONE_NAME". See framework-integ/README.md for details.');
-const domainName = process.env.CDK_INTEG_HOSTED_ZONE_NAME ?? process.env.DOMAIN_NAME;
-if (!domainName) throw new Error('For this test you must provide your own DomainName as an env var "DOMAIN_NAME". See framework-integ/README.md for details.');
+function getEnvVar(name: string, fallbackName?: string): string {
+  const value = process.env[name] || (fallbackName ? process.env[fallbackName] : undefined);
+  if (!value) throw new Error(`Environment variable ${name} is required.`);
+  return value;
+}
 
 const app = new App();
 const stack = new TestStack(app, 'cdk-amplify-app-custom-domain', {
-  hostedZoneId,
-  hostedZoneName,
-  domainName,
+  hostedZoneId: getEnvVar('CDK_INTEG_HOSTED_ZONE_ID', 'HOSTED_ZONE_ID'),
+  hostedZoneName: getEnvVar('CDK_INTEG_HOSTED_ZONE_NAME', 'HOSTED_ZONE_NAME'),
+  domainName: getEnvVar('CDK_INTEG_DOMAIN_NAME', 'DOMAIN_NAME'),
 });
 
 new IntegTest(app, 'amplify-app-custom-domain-integ', {