test: add architecture unit test

packages/aws-cdk-lib/aws-lambda/test/architecture.test.ts

@@ -0,0 +1,21 @@
+
+import { App, Stack } from '../../core';
+import * as lambda from '../lib';
+
+describe('architecture', () => {
+  const app = new App();
+  const stack = new Stack(app, 'stack');
+
+  test('toString to return the architecture name', () => {
+    // GIVEN
+    const testLambda = new lambda.Function(stack, 'testLambda', {
+      code: new lambda.InlineCode('foo'),
+      handler: 'index.handler',
+      runtime: lambda.Runtime.NODEJS_14_X,
+    },
+    );
+
+    // THEN
+    expect(`${testLambda.architecture}`).toEqual(testLambda.architecture.name);
+  });
+});