fix(apigateway): base path url cannot contain upper case characters (#…

…11799)

We're migrating an existing API Gateway application to CDK and have [hit this error](https://github.com/aws/aws-cdk/blob/2f0a598720f7ecf4dfea7dde97182940fcbe8d9a/packages/%40aws-cdk/aws-apigateway/lib/base-path-mapping.ts#L52), because our base paths include capitalised characters.

This PR resolves that issue and I've included some basics tests for the `BasePathMapping` resource.

----

*By submitting this pull request, I confirm that my contribution is made under the terms of the Apache-2.0 license*

packages/@aws-cdk/aws-apigateway/lib/base-path-mapping.ts

@@ -48,7 +48,7 @@ export class BasePathMapping extends Resource {
     super(scope, id);
 
     if (props.basePath && !Token.isUnresolved(props.basePath)) {
-      if (!props.basePath.match(/^[a-z0-9$_.+!*'()-]+$/)) {
+      if (!props.basePath.match(/^[a-zA-Z0-9$_.+!*'()-]+$/)) {
         throw new Error(`A base path may only contain letters, numbers, and one of "$-_.+!*'()", received: ${props.basePath}`);
       }
     }

packages/@aws-cdk/aws-apigateway/test/base-path-mapping.test.ts

@@ -0,0 +1,107 @@
+import '@aws-cdk/assert/jest';
+import * as acm from '@aws-cdk/aws-certificatemanager';
+import * as cdk from '@aws-cdk/core';
+import * as apigw from '../lib';
+
+describe('BasePathMapping', () => {
+  test('default setup', () => {
+    // GIVEN
+    const stack = new cdk.Stack();
+    const api = new apigw.RestApi(stack, 'MyApi');
+    api.root.addMethod('GET'); // api must have atleast one method.
+    const domain = new apigw.DomainName(stack, 'MyDomain', {
+      domainName: 'example.com',
+      certificate: acm.Certificate.fromCertificateArn(stack, 'cert', 'arn:aws:acm:us-east-1:1111111:certificate/11-3336f1-44483d-adc7-9cd375c5169d'),
+      endpointType: apigw.EndpointType.REGIONAL,
+    });
+
+    // WHEN
+    new apigw.BasePathMapping(stack, 'MyBasePath', {
+      restApi: api,
+      domainName: domain,
+    });
+
+    // THEN
+    expect(stack).toHaveResource('AWS::ApiGateway::BasePathMapping', {
+      DomainName: { Ref: 'MyDomainE4943FBC' },
+      RestApiId: { Ref: 'MyApi49610EDF' },
+    });
+  });
+
+  test('specify basePath property', () => {
+    // GIVEN
+    const stack = new cdk.Stack();
+    const api = new apigw.RestApi(stack, 'MyApi');
+    api.root.addMethod('GET'); // api must have atleast one method.
+    const domain = new apigw.DomainName(stack, 'MyDomain', {
+      domainName: 'example.com',
+      certificate: acm.Certificate.fromCertificateArn(stack, 'cert', 'arn:aws:acm:us-east-1:1111111:certificate/11-3336f1-44483d-adc7-9cd375c5169d'),
+      endpointType: apigw.EndpointType.REGIONAL,
+    });
+
+    // WHEN
+    new apigw.BasePathMapping(stack, 'MyBasePath', {
+      restApi: api,
+      domainName: domain,
+      basePath: 'My_B45E-P4th',
+    });
+
+    // THEN
+    expect(stack).toHaveResourceLike('AWS::ApiGateway::BasePathMapping', {
+      BasePath: 'My_B45E-P4th',
+    });
+  });
+
+  test('throw error for invalid basePath property', () => {
+    // GIVEN
+    const stack = new cdk.Stack();
+    const api = new apigw.RestApi(stack, 'MyApi');
+    api.root.addMethod('GET'); // api must have atleast one method.
+    const domain = new apigw.DomainName(stack, 'MyDomain', {
+      domainName: 'example.com',
+      certificate: acm.Certificate.fromCertificateArn(stack, 'cert', 'arn:aws:acm:us-east-1:1111111:certificate/11-3336f1-44483d-adc7-9cd375c5169d'),
+      endpointType: apigw.EndpointType.REGIONAL,
+    });
+
+    // WHEN
+    const invalidBasePath = '/invalid-/base-path';
+
+    // THEN
+    expect(() => {
+      new apigw.BasePathMapping(stack, 'MyBasePath', {
+        restApi: api,
+        domainName: domain,
+        basePath: invalidBasePath,
+      });
+    }).toThrowError(/base path may only contain/);
+  });
+
+  test('specify stage property', () => {
+    // GIVEN
+    const stack = new cdk.Stack();
+    const api = new apigw.RestApi(stack, 'MyApi');
+    api.root.addMethod('GET'); // api must have atleast one method.
+    const domain = new apigw.DomainName(stack, 'MyDomain', {
+      domainName: 'example.com',
+      certificate: acm.Certificate.fromCertificateArn(stack, 'cert', 'arn:aws:acm:us-east-1:1111111:certificate/11-3336f1-44483d-adc7-9cd375c5169d'),
+      endpointType: apigw.EndpointType.REGIONAL,
+    });
+    const stage = new apigw.Stage(stack, 'MyStage', {
+      deployment: new apigw.Deployment(stack, 'MyDeplouyment', {
+        api,
+      }),
+    });
+
+    // WHEN
+    new apigw.BasePathMapping(stack, 'MyBasePathMapping', {
+      restApi: api,
+      domainName: domain,
+      stage,
+    });
+
+    // THEN
+    expect(stack).toHaveResourceLike('AWS::ApiGateway::BasePathMapping', {
+      Stage: { Ref: 'MyStage572B0482' },
+    });
+  });
+});