chore(apigatewayv2): apiEndpoint is elevated to the IHttpApi interface (

aws#11988)

This was originally a miss from a community contributed PR.
`apiEndpoint` is a CloudFormation attribute and should be elevated into
the `IHttpApi` interface.

BREAKING CHANGE: `HttpApi.fromApiId()` has been replaced with
`HttpApi.fromHttpApiAttributes()`.


----

*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-apigatewayv2/lib/http/api.ts

@@ -18,6 +18,12 @@ export interface IHttpApi extends IResource {
    */
   readonly httpApiId: string;
 
+  /**
+   * The default endpoint for an API
+   * @attribute
+   */
+  readonly apiEndpoint: string;
+
   /**
    * The default stage
    */
@@ -184,6 +190,7 @@ export interface AddRoutesOptions extends BatchHttpRouteOptions {
 abstract class HttpApiBase extends Resource implements IHttpApi { // note that this is not exported
 
   public abstract readonly httpApiId: string;
+  public abstract readonly apiEndpoint: string;
   private vpcLinks: Record<string, VpcLink> = {};
 
   public metric(metricName: string, props?: cloudwatch.MetricOptions): cloudwatch.Metric {
@@ -233,6 +240,21 @@ abstract class HttpApiBase extends Resource implements IHttpApi { // note that t
   }
 }
 
+/**
+ * Attributes for importing an HttpApi into the CDK
+ */
+export interface HttpApiAttributes {
+  /**
+   * The identifier of the HttpApi
+   */
+  readonly httpApiId: string;
+  /**
+   * The endpoint URL of the HttpApi
+   * @default - throws an error if apiEndpoint is accessed.
+   */
+  readonly apiEndpoint?: string;
+}
+
 /**
  * Create a new API Gateway HTTP API endpoint.
  * @resource AWS::ApiGatewayV2::Api
@@ -241,9 +263,17 @@ export class HttpApi extends HttpApiBase {
   /**
    * Import an existing HTTP API into this CDK app.
    */
-  public static fromApiId(scope: Construct, id: string, httpApiId: string): IHttpApi {
+  public static fromHttpApiAttributes(scope: Construct, id: string, attrs: HttpApiAttributes): IHttpApi {
     class Import extends HttpApiBase {
-      public readonly httpApiId = httpApiId;
+      public readonly httpApiId = attrs.httpApiId;
+      private readonly _apiEndpoint = attrs.apiEndpoint;
+
+      public get apiEndpoint(): string {
+        if (!this._apiEndpoint) {
+          throw new Error('apiEndpoint is not configured on the imported HttpApi.');
+        }
+        return this._apiEndpoint;
+      }
     }
     return new Import(scope, id);
   }
@@ -252,13 +282,7 @@ export class HttpApi extends HttpApiBase {
    * A human friendly name for this HTTP API. Note that this is different from `httpApiId`.
    */
   public readonly httpApiName?: string;
-
   public readonly httpApiId: string;
-
-  /**
-   * The default endpoint for an API
-   * @attribute
-   */
   public readonly apiEndpoint: string;
 
   /**

packages/@aws-cdk/aws-apigatewayv2/test/http/api.test.ts

@@ -29,11 +29,10 @@ describe('HttpApi', () => {
 
   test('import', () => {
     const stack = new Stack();
-    const api = new HttpApi(stack, 'api', { apiName: 'customName' });
-    const imported = HttpApi.fromApiId(stack, 'imported', api.httpApiId );
-
-    expect(imported.httpApiId).toEqual(api.httpApiId);
+    const imported = HttpApi.fromHttpApiAttributes(stack, 'imported', { httpApiId: 'http-1234', apiEndpoint: 'api-endpoint' });
 
+    expect(imported.httpApiId).toEqual('http-1234');
+    expect(imported.apiEndpoint).toEqual('api-endpoint');
   });
 
   test('unsetting createDefaultStage', () => {
@@ -188,7 +187,7 @@ describe('HttpApi', () => {
       // GIVEN
       const stack = new Stack();
       const apiId = 'importedId';
-      const api = HttpApi.fromApiId(stack, 'test-api', apiId);
+      const api = HttpApi.fromHttpApiAttributes(stack, 'test-api', { httpApiId: apiId });
       const metricName = '4xxError';
       const statistic = 'Sum';
 
@@ -261,6 +260,13 @@ describe('HttpApi', () => {
 
     expect(api.apiEndpoint).toBeDefined();
   });
+
+  test('apiEndpoint for imported', () => {
+    const stack = new Stack();
+    const api = HttpApi.fromHttpApiAttributes(stack, 'imported', { httpApiId: 'api-1234' });
+
+    expect(() => api.apiEndpoint).toThrow(/apiEndpoint is not configured/);
+  });
 });
 
 class DummyRouteIntegration implements IHttpRouteIntegration {