add(angel3): adding re-branded angel3 exception package

packages/exceptions/.gitignore

@@ -0,0 +1,71 @@
+# See https://www.dartlang.org/tools/private-files.html
+
+# Files and directories created by pub
+.dart_tool
+.packages
+.pub/
+build/
+
+# If you're building an application, you may want to check-in your pubspec.lock
+pubspec.lock
+
+# Directory created by dartdoc
+# If you don't generate documentation locally you can remove this line.
+doc/api/
+
+### Dart template
+# See https://www.dartlang.org/tools/private-files.html
+
+# Files and directories created by pub
+
+# SDK 1.20 and later (no longer creates packages directories)
+
+# Older SDK versions
+# (Include if the minimum SDK version specified in pubsepc.yaml is earlier than 1.20)
+.project
+.buildlog
+**/packages/
+
+
+# Files created by dart2js
+# (Most Dart developers will use pub build to compile Dart, use/modify these
+#  rules if you intend to use dart2js directly
+#  Convention is to use extension '.dart.js' for Dart compiled to Javascript to
+#  differentiate from explicit Javascript files)
+*.dart.js
+*.part.js
+*.js.deps
+*.js.map
+*.info.json
+
+# Directory created by dartdoc
+
+# Don't commit pubspec lock file
+# (Library packages only! Remove pattern if developing an application package)
+### JetBrains template
+# Covers JetBrains IDEs: IntelliJ, RubyMine, PhpStorm, AppCode, PyCharm, CLion, Android Studio and Webstorm
+# Reference: https://intellij-support.jetbrains.com/hc/en-us/articles/206544839
+
+# User-specific stuff:
+
+## VsCode
+.vscode/
+
+## File-based project format:
+*.iws
+
+## Plugin-specific files:
+
+# IntelliJ
+.idea/
+/out/
+.idea_modules/
+
+# JIRA plugin
+atlassian-ide-plugin.xml
+
+# Crashlytics plugin (for Android Studio and IntelliJ)
+com_crashlytics_export_strings.xml
+crashlytics.properties
+crashlytics-build.properties
+fabric.properties

packages/exceptions/AUTHORS.md

@@ -0,0 +1,12 @@
+Primary Authors
+===============
+
+* __[Thomas Hii](dukefirehawk.apps@gmail.com)__
+
+    Thomas is the current maintainer of the code base. He has refactored and migrated the 
+    code base to support NNBD.
+
+* __[Tobe O](thosakwe@gmail.com)__
+
+    Tobe has written much of the original code prior to NNBD migration. He has moved on and
+    is no longer involved with the project.

packages/exceptions/CHANGELOG.md

@@ -0,0 +1,72 @@
+
+# Change Log
+
+## 8.1.1
+
+* Updated repository link
+
+## 8.1.0
+
+* Updated `lints` to 3.0.0
+
+## 8.0.0
+
+* Require Dart >= 3.0
+
+## 7.0.0
+
+* Require Dart >= 2.17
+
+## 6.0.1
+
+* Updated README
+
+## 6.0.0
+
+* Require Dart >= 2.16
+* [**Breaking**] `error` for `AngelHttpException` is no longer mandatory
+
+## 5.0.0
+
+* Skipped release
+
+## 4.0.0
+
+* Skipped release
+
+## 3.1.0
+
+* Upgraded to `lints` linter
+
+## 3.0.2
+
+* Updated LICENSE link
+
+## 3.0.1
+
+* Updated README
+
+## 3.0.0
+
+* Migrated to support Dart >= 2.12 NNBD
+
+## 2.0.0
+
+* Migrated to work with Dart >= 2.12 Non NNBD
+
+## 1.1.0
+
+* Emit `is_error` and `status_code` in `toJson()`.
+* No more `camelCase` at all.
+
+## 1.0.0+3
+
+* Slightly relax the deserialization of `errors`.
+
+## 1.0.0+2
+
+* Added a backwards-compatible way to cast the `errors` List.
+
+## 1.0.0+1
+
+* Dart 2 updates.

packages/exceptions/LICENSE

@@ -0,0 +1,29 @@
+BSD 3-Clause License
+
+Copyright (c) 2021, dukefirehawk.com
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are met:
+
+1. Redistributions of source code must retain the above copyright notice, this
+   list of conditions and the following disclaimer.
+
+2. Redistributions in binary form must reproduce the above copyright notice,
+   this list of conditions and the following disclaimer in the documentation
+   and/or other materials provided with the distribution.
+
+3. Neither the name of the copyright holder nor the names of its
+   contributors may be used to endorse or promote products derived from
+   this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

packages/exceptions/README.md

@@ -0,0 +1,8 @@
+# Angel3 Http Exception
+
+![Pub Version (including pre-releases)](https://img.shields.io/pub/v/angel3_http_exception?include_prereleases)
+[![Null Safety](https://img.shields.io/badge/null-safety-brightgreen)](https://dart.dev/null-safety)
+[![Gitter](https://img.shields.io/gitter/room/angel_dart/discussion)](https://gitter.im/angel_dart/discussion)
+[![License](https://img.shields.io/github/license/dart-backend/angel)](https://github.com/dart-backend/angel/tree/master/packages/http_exception/LICENSE)
+
+Exception class that can be serialized to JSON and serialized to clients. Angel3's HTTP exception class.

packages/exceptions/analysis_options.yaml

@@ -0,0 +1 @@
+include: package:lints/recommended.yaml

packages/exceptions/example/main.dart

@@ -0,0 +1,3 @@
+import 'package:platform_exceptions/http_exception.dart';
+
+void main() => throw HttpException.notFound(message: "Can't find that page!");

packages/exceptions/lib/http_exception.dart

@@ -0,0 +1,121 @@
+library http_exception;
+
+//import 'package:dart2_constant/convert.dart';
+import 'dart:convert';
+
+/// Exception class that can be serialized to JSON and serialized to clients.
+/// Carries HTTP-specific metadata, like [statusCode].
+///
+/// Originally inspired by
+/// [feathers-errors](https://github.com/feathersjs/feathers-errors).
+class HttpException implements Exception {
+  /// A list of errors that occurred when this exception was thrown.
+  final List<String> errors = [];
+
+  /// The error throw by exception.
+  dynamic error;
+
+  /// The cause of this exception.
+  String message;
+
+  /// The [StackTrace] associated with this error.
+  StackTrace? stackTrace;
+
+  /// An HTTP status code this exception will throw.
+  int statusCode;
+
+  HttpException(
+      {this.message = '500 Internal Server Error',
+      this.stackTrace,
+      this.statusCode = 500,
+      this.error,
+      List<String> errors = const []}) {
+    this.errors.addAll(errors);
+  }
+
+  Map toJson() {
+    return {
+      'is_error': true,
+      'status_code': statusCode,
+      'message': message,
+      'errors': errors
+    };
+  }
+
+  Map toMap() => toJson();
+
+  @override
+  String toString() {
+    return '$statusCode: $message';
+  }
+
+  factory HttpException.fromMap(Map data) {
+    return HttpException(
+      statusCode: (data['status_code'] ?? data['statusCode'] ?? 500) as int,
+      message: data['message']?.toString() ?? 'Internal Server Error',
+      errors: data['errors'] is Iterable
+          ? ((data['errors'] as Iterable).map((x) => x.toString()).toList())
+          : <String>[],
+    );
+  }
+
+  factory HttpException.fromJson(String str) =>
+      HttpException.fromMap(json.decode(str) as Map);
+
+  /// Throws a 400 Bad Request error, including an optional arrray of (validation?)
+  /// errors you specify.
+  factory HttpException.badRequest(
+          {String message = '400 Bad Request',
+          List<String> errors = const []}) =>
+      HttpException(message: message, errors: errors, statusCode: 400);
+
+  /// Throws a 401 Not Authenticated error.
+  factory HttpException.notAuthenticated(
+          {String message = '401 Not Authenticated'}) =>
+      HttpException(message: message, statusCode: 401);
+
+  /// Throws a 402 Payment Required error.
+  factory HttpException.paymentRequired(
+          {String message = '402 Payment Required'}) =>
+      HttpException(message: message, statusCode: 402);
+
+  /// Throws a 403 Forbidden error.
+  factory HttpException.forbidden({String message = '403 Forbidden'}) =>
+      HttpException(message: message, statusCode: 403);
+
+  /// Throws a 404 Not Found error.
+  factory HttpException.notFound({String message = '404 Not Found'}) =>
+      HttpException(message: message, statusCode: 404);
+
+  /// Throws a 405 Method Not Allowed error.
+  factory HttpException.methodNotAllowed(
+          {String message = '405 Method Not Allowed'}) =>
+      HttpException(message: message, statusCode: 405);
+
+  /// Throws a 406 Not Acceptable error.
+  factory HttpException.notAcceptable(
+          {String message = '406 Not Acceptable'}) =>
+      HttpException(message: message, statusCode: 406);
+
+  /// Throws a 408 Timeout error.
+  factory HttpException.methodTimeout({String message = '408 Timeout'}) =>
+      HttpException(message: message, statusCode: 408);
+
+  /// Throws a 409 Conflict error.
+  factory HttpException.conflict({String message = '409 Conflict'}) =>
+      HttpException(message: message, statusCode: 409);
+
+  /// Throws a 422 Not Processable error.
+  factory HttpException.notProcessable(
+          {String message = '422 Not Processable'}) =>
+      HttpException(message: message, statusCode: 422);
+
+  /// Throws a 501 Not Implemented error.
+  factory HttpException.notImplemented(
+          {String message = '501 Not Implemented'}) =>
+      HttpException(message: message, statusCode: 501);
+
+  /// Throws a 503 Unavailable error.
+  factory HttpException.unavailable({String message = '503 Unavailable'}) =>
+      HttpException(message: message, statusCode: 503);
+}

packages/exceptions/pubspec.yaml

@@ -0,0 +1,9 @@
+name: platform_exceptions
+version: 9.0.0
+description: Exception pakcage
+homepage: https://angel3-framework.web.app/
+repository: https://github.com/dart-backend/angel/tree/master/packages/http_exception
+environment:
+  sdk: '>=3.3.0 <4.0.0'
+dev_dependencies:
+  lints: ^4.0.0