feat(amplify): automatic branch deletion

packages/@aws-cdk/aws-amplify/README.md

@@ -140,14 +140,17 @@ app.addBranch('feature/next', {
 });
 ```
 
-### Automatically creating branches
-Use the `autoBranchCreation` prop to automatically create new branches:
+### Automatically creating and deleting branches
+Use the `autoBranchCreation` and `autoBranchDeletion` props to control creation/deletion
+of branches:
+
 ```ts
 const amplifyApp = new amplify.App(this, 'MyApp', {
   repository: 'https://github.com/<user>/<repo>',
   oauthToken: cdk.SecretValue.secretsManager('my-github-token'),
-  autoBranchCreation: {
+  autoBranchCreation: { // Automatically connect branches that match a pattern set
     patterns: ['feature/*', 'test/*']
   }
+  autoBranchDeletion: true, // Automatically disconnect a branch when you delete a branch from your repository
 });
 ```

packages/@aws-cdk/aws-amplify/lib/app.ts

@@ -91,6 +91,14 @@ export interface AppProps {
    */
   readonly autoBranchCreation?: AutoBranchCreation;
 
+  /**
+   * Automatically disconnect a branch in the Amplify Console when you delete a
+   * branch from your Git repository.
+   *
+   * @default false
+   */
+  readonly autoBranchDeletion?: boolean;
+
   /**
    * The Basic Auth configuration. Use this to set password protection at an
    * app level to all your branches.
@@ -210,11 +218,12 @@ export class App extends Resource implements IApp, iam.IGrantable {
         buildSpec: props.autoBranchCreation.buildSpec && props.autoBranchCreation.buildSpec.toBuildSpec(),
         enableAutoBranchCreation: true,
         enableAutoBuild: props.autoBranchCreation.autoBuild === undefined ? true : props.autoBranchCreation.autoBuild,
-        environmentVariables: Lazy.anyValue({ produce: () => renderEnvironmentVariables(this.autoBranchEnvironmentVariables )}, { omitEmptyArray: true }), // eslint-disable-line max-len
+        environmentVariables: Lazy.anyValue({ produce: () => renderEnvironmentVariables(this.autoBranchEnvironmentVariables ) }, { omitEmptyArray: true }), // eslint-disable-line max-len
         enablePullRequestPreview: props.autoBranchCreation.pullRequestPreview === undefined ? true : props.autoBranchCreation.pullRequestPreview,
         pullRequestEnvironmentName: props.autoBranchCreation.pullRequestEnvironmentName,
         stage: props.autoBranchCreation.stage,
       },
+      enableBranchAutoDeletion: props.autoBranchDeletion,
       basicAuthConfig: props.basicAuth && props.basicAuth.bind(this, 'AppBasicAuth'),
       buildSpec: props.buildSpec && props.buildSpec.toBuildSpec(),
       customRules: Lazy.anyValue({ produce: () => this.customRules }, { omitEmptyArray: true }),

packages/@aws-cdk/aws-amplify/test/app.test.ts

@@ -371,3 +371,20 @@ test('with auto branch creation', () => {
     },
   });
 });
+
+test('with auto branch deletion', () => {
+  // WHEN
+  new amplify.App(stack, 'App', {
+    sourceCodeProvider: new amplify.GitHubSourceCodeProvider({
+      owner: 'aws',
+      repository: 'aws-cdk',
+      oauthToken: SecretValue.plainText('secret'),
+    }),
+    autoBranchDeletion: true,
+  });
+
+  // THEN
+  expect(stack).toHaveResource('AWS::Amplify::App', {
+    EnableBranchAutoDeletion: true,
+  });
+});