Use 'pkg' and 'packages' to trigger suggestions for the pub command (#3731)

lib/src/pub_embeddable_command.dart

diff --git a/lib/src/pub_embeddable_command.dart b/lib/src/pub_embeddable_command.dart
index a12efe4..29ac73f 100644
--- a/lib/src/pub_embeddable_command.dart
+++ b/lib/src/pub_embeddable_command.dart
@@ -47,6 +47,10 @@
 class PubEmbeddableCommand extends PubCommand implements PubTopLevel {
   @override
   String get name => 'pub';
+
+  @override
+  get suggestionAliases => const ['packages', 'pkg'];
+
   @override
   String get description => 'Work with packages.';
   @override

pubspec.yaml

diff --git a/pubspec.yaml b/pubspec.yaml
index d34a3f5..447ee06 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -7,7 +7,7 @@
   # Note: Pub's test infrastructure assumes that any dependencies used in tests
   # will be hosted dependencies.
   analyzer: ^5.1.0
-  args: ^2.1.0
+  args: ^2.4.0
   async: ^2.6.1
   cli_util: ^0.3.5
   collection: ^1.15.0

test/embedding/embedding_test.dart

diff --git a/test/embedding/embedding_test.dart b/test/embedding/embedding_test.dart
index a234ec2..8a7d59b 100644
--- a/test/embedding/embedding_test.dart
+++ b/test/embedding/embedding_test.dart
@@ -7,6 +7,7 @@
 
 import 'package:path/path.dart' as path;
 import 'package:path/path.dart' as p;
+import 'package:pub/src/exit_codes.dart';
 import 'package:pub/src/io.dart' show EnvironmentKeys;
 import 'package:test/test.dart';
 import 'package:test_process/test_process.dart';
@@ -392,6 +393,27 @@
       ),
     );
   });
+
+  test('"pkg" and "packages" will trigger a suggestion of "pub"', () async {
+    await servePackages();
+    await d.appDir().create();
+    for (final command in ['pkg', 'packages']) {
+      final buffer = StringBuffer();
+      await runEmbeddingToBuffer(
+        [command, 'get'],
+        buffer,
+        workingDirectory: d.path(appPath),
+        exitCode: USAGE,
+      );
+      expect(
+        buffer.toString(),
+        allOf(
+          contains('Did you mean one of these?'),
+          contains('  pub'),
+        ),
+      );
+    }
+  });
 }
 
 String _filter(String input) {