chore(amplify_storage_s3): add storage integration tests and update example app

CONTRIBUTING.md

@@ -269,6 +269,9 @@ Finally, run a push to update the resources with the new function resource (lamb
 $ amplify push
 ```
 
+Additionally, the storage category requires some manual configuration as the [headless CLI does not yet support storage](https://github.com/aws-amplify/amplify-cli/issues/7378). Those instructions 
+are notes in the [storage example app](packages/amplify_storage_s3/example/README.md).
+
 ## Code of Conduct
 
 This project has adopted the [Amazon Open Source Code of Conduct](https://aws.github.io/code-of-conduct).

packages/amplify_storage_s3/example/.gitignore

@@ -56,8 +56,8 @@ node_modules/
 aws-exports.js
 awsconfiguration.json
 amplifyconfiguration.json
+amplifyconfiguration.dart
 amplify-build-config.json
 amplify-gradle-config.json
 amplifytools.xcconfig
 .secret-*
-

packages/amplify_storage_s3/example/README.md

@@ -1,3 +1,54 @@
 # amplify_storage_s3_example
 
 Example app for the Amplify Flutter Storage plugin with AWS S3 provider.
+
+## How to Configure Amplify Backend
+
+This app (as well as integration tests) depend on an Amplify backend with the storage category 
+configured for guest access.
+
+First, initialize the Amplify backend with:
+
+```
+$ cd packages/amplify_storage_s3/example
+$ amplify init
+```
+
+After completing the prompts, add storage category.
+
+```
+$ amplify add storage
+  ? Please select from one of the below mentioned services: Content (Images, audio, video, etc.)
+  ? You need to add auth (Amazon Cognito) to your project in order to add storage for user files. Do you want to add auth now?
+    Yes
+  Using service: Cognito, provided by: awscloudformation
+
+  The current configured provider is Amazon Cognito. 
+
+  Do you want to use the default authentication and security configuration? Default configuration
+  Warning: you will not be able to edit these selections. 
+  How do you want users to be able to sign in?
+    Username
+  Do you want to configure advanced settings?
+    No, I am done.
+  Successfully added auth resource MYRESOURCENAME locally
+
+  Some next steps:
+  "amplify push" will build all your local backend resources and provision it in the cloud
+  "amplify publish" will build all your local backend and frontend resources (if you have hosting category added) and provision it in the cloud
+
+  ? Please provide a friendly name for your resource that will be used to label this category in the project:
+    myGreatProjectNameStorage
+  ? Please provide bucket name:
+    exampleBucketNameUnique12345
+  ? Who should have access:
+    Auth and guest users
+  ? What kind of access do you want for Authenticated users?
+    create/update, read, delete
+  ? What kind of access do you want for Guest users?
+    create/update, read, delete
+  ? Do you want to add a Lambda Trigger for your S3 Bucket?
+    No
+```
+
+Finally, run `$ amplify push` to provision the storage resource in the cloud.

packages/amplify_storage_s3/example/android/build.gradle

@@ -6,7 +6,7 @@ buildscript {
     }
 
     dependencies {
-        classpath 'com.android.tools.build:gradle:3.5.0'
+        classpath 'com.android.tools.build:gradle:3.5.4'
         classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
     }
 }

packages/amplify_storage_s3/example/integration_test/main_test.dart

@@ -0,0 +1,122 @@
+/*
+ * Copyright 2021 Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License").
+ * You may not use this file except in compliance with the License.
+ * A copy of the License is located at
+ *
+ *  http://aws.amazon.com/apache2.0
+ *
+ * or in the "license" file accompanying this file. This file is distributed
+ * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
+ * express or implied. See the License for the specific language governing
+ * permissions and limitations under the License.
+ */
+import 'dart:io';
+import 'package:path_provider/path_provider.dart';
+import 'package:integration_test/integration_test.dart';
+import 'package:flutter_test/flutter_test.dart';
+
+import 'package:amplify_flutter/amplify.dart';
+import 'package:amplify_auth_cognito/amplify_auth_cognito.dart';
+import 'package:amplify_storage_s3/amplify_storage_s3.dart';
+import 'package:amplify_storage_s3_example/amplifyconfiguration.dart';
+
+const exampleFileName = 'example_file.txt';
+
+void main() async {
+  IntegrationTestWidgetsFlutterBinding.ensureInitialized();
+
+  group('amplify_storage_s3', () {
+    // options used for all tests
+    S3ListOptions listOptions =
+        S3ListOptions(accessLevel: StorageAccessLevel.guest);
+    late String? lastUploadedKey;
+
+    // Returns a text file to use for testing, writing if it does not exist.
+    Future<File> getTemporaryFile() async {
+      final path = '${(await getTemporaryDirectory()).path}/$exampleFileName';
+      final file = File(path);
+      if (!(await file.exists())) {
+        await file.writeAsString('Upload me to s3 to see if I work.');
+      }
+      return file;
+    }
+
+    Future<int> getCountFromListFiles() async {
+      final result = await Amplify.Storage.list(options: listOptions);
+      return result.items.length;
+    }
+
+    Future<void> deleteAllGuestFiles() async {
+      final result = await Amplify.Storage.list(options: listOptions);
+      for (StorageItem item in result.items) {
+        await Amplify.Storage.remove(key: item.key);
+      }
+    }
+
+    setUpAll(() async {
+      Amplify.addPlugins([AmplifyAuthCognito(), AmplifyStorageS3()]);
+      await Amplify.configure(amplifyconfig);
+
+      await deleteAllGuestFiles();
+    });
+
+    tearDownAll(() async {
+      await deleteAllGuestFiles();
+    });
+
+    testWidgets('should upload a file', (WidgetTester tester) async {
+      final file = await getTemporaryFile();
+      final initialCount = await getCountFromListFiles();
+
+      final key = '$exampleFileName${new DateTime.now().toString()}';
+      Map<String, String> metadata = <String, String>{};
+      metadata['name'] = exampleFileName;
+      metadata['desc'] = 'A test file';
+      S3UploadFileOptions options = S3UploadFileOptions(
+          accessLevel: StorageAccessLevel.guest, metadata: metadata);
+      final result = await Amplify.Storage.uploadFile(
+          key: key, local: file, options: options);
+      lastUploadedKey = result.key;
+      expect(lastUploadedKey, key);
+
+      final finalCount = await getCountFromListFiles();
+      expect(initialCount + 1, finalCount);
+    });
+
+    testWidgets('should list files and get expected attributes',
+        (WidgetTester tester) async {
+      if (lastUploadedKey == null) {
+        fail('No uploaded file to verify.');
+      }
+      final result = await Amplify.Storage.list(options: listOptions);
+      expect(result.items.length, greaterThan(0));
+      final uploadedStorageItem =
+          result.items.firstWhere((element) => element.key == lastUploadedKey);
+      expect(uploadedStorageItem.lastModified?.day,
+          new DateTime.now().day); // was uploaded today
+      expect(uploadedStorageItem.eTag?.isNotEmpty, true);
+      expect(uploadedStorageItem.size, greaterThan(0));
+    });
+
+    testWidgets('should get the URL of an uploaded file',
+        (WidgetTester tester) async {
+      if (lastUploadedKey == null) {
+        fail('No uploaded file to verify.');
+      }
+      final result = await Amplify.Storage.getUrl(key: lastUploadedKey!);
+      // assert valid and expected s3 URL
+      expect(Uri.parse(result.url).isAbsolute, true);
+      expect(result.url.contains('s3'), true);
+    });
+
+    testWidgets('should delete uploaded files', (WidgetTester tester) async {
+      final initialCount = await getCountFromListFiles();
+      expect(initialCount, greaterThan(0));
+      await deleteAllGuestFiles();
+      final finalCount = await getCountFromListFiles();
+      expect(finalCount, 0);
+    });
+  });
+}

packages/amplify_storage_s3/example/lib/main.dart

@@ -64,7 +64,13 @@ class _MyAppState extends State<MyApp> {
     try {
       print('In upload');
       // Uploading the file with options
-      File local = await FilePicker.getFile(type: FileType.image);
+      FilePickerResult? pickResult =
+          await FilePicker.platform.pickFiles(type: FileType.image);
+      if (pickResult == null) {
+        print('User canceled upload.');
+        return;
+      }
+      File local = File(pickResult.files.single.path!);
       final key = new DateTime.now().toString();
       Map<String, String> metadata = <String, String>{};
       metadata['name'] = 'filename';

packages/amplify_storage_s3/example/pubspec.yaml

@@ -6,12 +6,13 @@ description: Demonstrates how to use the amplify_storage_s3 plugin.
 publish_to: "none" # Remove this line if you wish to publish to pub.dev
 
 environment:
-  sdk: ">=2.7.0 <3.0.0"
+  sdk: ">=2.12.0 <3.0.0"
+  flutter: ">=2.2.0"
 
 dependencies:
   flutter:
     sdk: flutter
-  file_picker: ^1.8.0+1
+  file_picker: ^3.0.3
   amplify_flutter:
     path: ../../amplify_flutter
   amplify_auth_cognito:
@@ -32,6 +33,12 @@ dependencies:
 dev_dependencies:
   flutter_test:
     sdk: flutter
+  flutter_driver:
+    sdk: flutter
+  integration_test:
+    sdk: flutter
+  path_provider: ^2.0.2
+
 
 # For information on the generic Dart part of this file, see the
 # following page: https://dart.dev/tools/pub/pubspec

packages/amplify_storage_s3/example/test_driver/integration_test.dart

@@ -0,0 +1,18 @@
+/*
+ * Copyright 2021 Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License").
+ * You may not use this file except in compliance with the License.
+ * A copy of the License is located at
+ *
+ *  http://aws.amazon.com/apache2.0
+ *
+ * or in the "license" file accompanying this file. This file is distributed
+ * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
+ * express or implied. See the License for the specific language governing
+ * permissions and limitations under the License.
+ */
+
+import 'package:integration_test/integration_test_driver.dart';
+
+Future<void> main() => integrationDriver();