feat(aft): Adds review for generating code review requests text

packages/aft/lib/src/command_runner.dart

@@ -2,6 +2,7 @@
 // SPDX-License-Identifier: Apache-2.0
 
 import 'package:aft/aft.dart';
+import 'package:aft/src/commands/review_command.dart';
 import 'package:aft/src/commands/save_repo_state_command.dart';
 import 'package:args/command_runner.dart';
 
@@ -32,7 +33,8 @@ Future<void> run(List<String> args) async {
     ..addCommand(SaveRepoStateCommand())
     ..addCommand(RunCommand())
     ..addCommand(DocsCommand())
-    ..addCommand(ServeCommand());
+    ..addCommand(ServeCommand())
+    ..addCommand(ReviewCommand());
 
   try {
     final argResults = runner.argParser.parse(args);

packages/aft/lib/src/commands/review_command.dart

@@ -0,0 +1,149 @@
+// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+// SPDX-License-Identifier: Apache-2.0
+
+import 'dart:convert';
+import 'dart:io';
+
+import 'package:aft/aft.dart';
+
+class GitHubData {
+  GitHubData.fromJson(Map<String, dynamic> json)
+      : title = json['title'] as String,
+        body = json['body'] as String,
+        number = json['number'] as int,
+        changedFiles = json['changedFiles'] as int,
+        additions = json['additions'] as int,
+        deletions = json['deletions'] as int,
+        url = json['url'] as String;
+
+  String title;
+  String body;
+  int number;
+  int changedFiles;
+  int additions;
+  int deletions;
+  String url;
+
+  final String _legal =
+      'By submitting this pull request, I confirm that you can use, modify, copy, and redistribute this contribution, under the terms of your choice.';
+  final String _lineBreak = '========================================';
+
+  final emojis = {
+    ReviewPriority.urgent: ':alert:',
+    ReviewPriority.high: ':arrow_double_up:',
+    ReviewPriority.normal: ':arrow_up:',
+    ReviewPriority.low: ':arrow_down:',
+  };
+
+  @override
+  String toString() {
+    return '{Title: $title,\nBody: $body,\nNumber: $number,\nChanged Files: $changedFiles,\nAdditions: $additions,\nDeletions: $deletions}';
+  }
+
+  /// Converts the PR data to a Slack-formatted string.
+  String toMarkdown(ReviewPriority priority) {
+    return '''
+$_lineBreak
+${emojis[priority]} *$title - [$number]($url)*
+> +$additions -$deletions | files: $changedFiles
+${body.replaceAll(_legal, '').trim()}
+*Reviewers:*  
+$_lineBreak''';
+  }
+}
+
+enum ReviewPriority { urgent, high, normal, low }
+
+/// Command to clean all temporary files in the repo.
+class ReviewCommand extends AmplifyCommand {
+  ReviewCommand() {
+    argParser
+      ..addOption(
+        'ref',
+        abbr: 'r',
+        help:
+            'The PR reference. Can be a PR number or URL. Defaults to the current branch.',
+      )
+      ..addOption(
+        'priority',
+        abbr: 'p',
+        help: 'Determines the emoji to use for the PR review.',
+        allowed: ReviewPriority.values.map((e) => e.name).toList(),
+        defaultsTo: ReviewPriority.normal.name,
+      );
+  }
+  @override
+  String get description => 'Creates PR review text for slack';
+
+  @override
+  String get name => 'review';
+
+  /// The PR ref to review.
+  late final ref = argResults?['ref'] as String? ?? '';
+
+  /// Determines the emoji to use for the PR review.
+  late final priority = ReviewPriority.values.firstWhere(
+    (e) => e.name == argResults!['priority'] as String,
+    orElse: () => ReviewPriority.normal,
+  );
+
+  /// Verifies that the PR is ready using gh CLI.
+  Future<void> _verifyPR(String ref) async {
+    final branchName = await Process.run(
+      'gh',
+      ['pr', 'ready', ref],
+    );
+    if (branchName.exitCode != 0) {
+      final error = branchName.stderr.toString();
+      if (error.contains('Could not resolve to a PullRequest')) {
+        logger.error('A PR is not ready at ref: $ref');
+      } else {
+        logger.error('Invalid ref: $error');
+      }
+      exit(1);
+    }
+  }
+
+  /// Fetches PR data from GitHub using gh CLI.
+  Future<GitHubData> _getGitHubData(String ref) async {
+    final process = await Process.run(
+      'gh',
+      [
+        'pr',
+        'view',
+        ref,
+        '--json',
+        'title,body,number,changedFiles,additions,deletions,url',
+      ],
+    );
+    if (process.exitCode != 0) {
+      logger.error('Could not fetch PR data from GitHub');
+      exit(1);
+    }
+    if (process.stdout is! String) {
+      logger.error('GitHub data is not a string');
+      exit(1);
+    }
+
+    final prDataJson =
+        jsonDecode(process.stdout as String) as Map<String, dynamic>;
+    final prData = GitHubData.fromJson(prDataJson);
+    return prData;
+  }
+
+  @override
+  Future<void> run() async {
+    await super.run();
+
+    await _verifyPR(ref);
+
+    final ghData = await _getGitHubData(ref);
+
+    final slackString = ghData.toMarkdown(priority);
+
+    logger
+      ..info(slackString)
+      ..info('After pasting into slack, press CMD+SHIFT+F to format the text.')
+      ..info('Review output was successful!');
+  }
+}