test: add a test for an expired cert (#4103)

packages/aws_common/test/http/bad_certificate_test.dart

@@ -0,0 +1,37 @@
+// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+// SPDX-License-Identifier: Apache-2.0
+
+import 'package:aws_common/aws_common.dart';
+import 'package:test/test.dart';
+
+final expiredCertUrl = Uri.parse('https://expired.badssl.com/');
+
+void main() {
+  group('AWSHttpClient', () {
+    test('throws by default for expired certificates', () async {
+      final client = AWSHttpClient();
+      final request = AWSHttpRequest.get(expiredCertUrl);
+      final operation = client.send(request);
+      await expectLater(
+        operation.response,
+        throwsA(isA<AWSHttpException>()),
+      );
+    });
+
+    test(
+      'does not throw when onBadCertificate is overridden',
+      () async {
+        final client = AWSHttpClient()
+          ..onBadCertificate = (p0, host, port) => true;
+        final request = AWSHttpRequest.get(expiredCertUrl);
+        final operation = client.send(request);
+        expect(
+          operation.response,
+          completes,
+        );
+      },
+      // onBadCertificate override is only used on vm
+      skip: zIsWeb,
+    );
+  });
+}