Remove superfluous periods from `pub --help` subcommand descriptions. (#106925)

* Remove periods from pub --help command descriptions

* Add trailing period consistently

* Remove added period from PackagesInteractiveGetCommand description

* Verify line ending for first line of command description

* Update _allowedTrailingPatterns to validate that lines end with only one period, bang, or colon

packages/flutter_tools/lib/src/commands/packages.dart

@@ -25,17 +25,17 @@ class PackagesCommand extends FlutterCommand {
     addSubcommand(PackagesInteractiveGetCommand('add', 'Add a dependency to pubspec.yaml.'));
     addSubcommand(PackagesInteractiveGetCommand('remove', 'Removes a dependency from the current package.'));
     addSubcommand(PackagesTestCommand());
-    addSubcommand(PackagesForwardCommand('publish', 'Publish the current package to pub.dartlang.org', requiresPubspec: true));
-    addSubcommand(PackagesForwardCommand('downgrade', 'Downgrade packages in a Flutter project', requiresPubspec: true));
-    addSubcommand(PackagesForwardCommand('deps', 'Print package dependencies')); // path to package can be specified with --directory argument
-    addSubcommand(PackagesForwardCommand('run', 'Run an executable from a package', requiresPubspec: true));
-    addSubcommand(PackagesForwardCommand('cache', 'Work with the Pub system cache'));
-    addSubcommand(PackagesForwardCommand('version', 'Print Pub version'));
-    addSubcommand(PackagesForwardCommand('uploader', 'Manage uploaders for a package on pub.dev'));
+    addSubcommand(PackagesForwardCommand('publish', 'Publish the current package to pub.dartlang.org.', requiresPubspec: true));
+    addSubcommand(PackagesForwardCommand('downgrade', 'Downgrade packages in a Flutter project.', requiresPubspec: true));
+    addSubcommand(PackagesForwardCommand('deps', 'Print package dependencies.')); // path to package can be specified with --directory argument
+    addSubcommand(PackagesForwardCommand('run', 'Run an executable from a package.', requiresPubspec: true));
+    addSubcommand(PackagesForwardCommand('cache', 'Work with the Pub system cache.'));
+    addSubcommand(PackagesForwardCommand('version', 'Print Pub version.'));
+    addSubcommand(PackagesForwardCommand('uploader', 'Manage uploaders for a package on pub.dev.'));
     addSubcommand(PackagesForwardCommand('login', 'Log into pub.dev.'));
     addSubcommand(PackagesForwardCommand('logout', 'Log out of pub.dev.'));
-    addSubcommand(PackagesForwardCommand('global', 'Work with Pub global packages'));
-    addSubcommand(PackagesForwardCommand('outdated', 'Analyze dependencies to find which ones can be upgraded', requiresPubspec: true));
+    addSubcommand(PackagesForwardCommand('global', 'Work with Pub global packages.'));
+    addSubcommand(PackagesForwardCommand('outdated', 'Analyze dependencies to find which ones can be upgraded.', requiresPubspec: true));
     addSubcommand(PackagesForwardCommand('token', 'Manage authentication tokens for hosted pub repositories.'));
     addSubcommand(PackagesPassthroughCommand());
   }
@@ -233,7 +233,7 @@ class PackagesForwardCommand extends FlutterCommand {
 
   @override
   String get description {
-    return '$_description.\n'
+    return '$_description\n'
            'This runs the "pub" tool in a Flutter context.';
   }
 
@@ -290,7 +290,7 @@ class PackagesInteractiveGetCommand extends FlutterCommand {
 
   @override
   String get description {
-    return '$_description.\n'
+    return '$_description\n'
            'This runs the "pub" tool in a Flutter context.';
   }
 

packages/flutter_tools/test/general.shard/args_test.dart

@@ -85,6 +85,10 @@ void verifyCommandRunner(CommandRunner<Object> runner) {
 void verifyCommand(Command<Object> runner) {
   expect(runner.argParser, isNotNull, reason: 'command ${runner.name} has no argParser');
   verifyOptions(runner.name, runner.argParser.options.values);
+
+  final String firstDescriptionLine = runner.description.split('\n').first;
+  expect(firstDescriptionLine, matches(_allowedTrailingPatterns), reason: "command ${runner.name}'s description does not end with the expected single period that a full sentence should end with");
+
   if (runner.hidden == false && runner.parent == null) {
     expect(
       runner.category,
@@ -107,7 +111,7 @@ final RegExp _bannedArgumentNamePattern = RegExp(r'-uri$');
 
 // Patterns for help messages.
 final RegExp _bannedLeadingPatterns = RegExp(r'^[-a-z]', multiLine: true);
-final RegExp _allowedTrailingPatterns = RegExp(r'([^ ][.!:]\)?|: https?://[^ ]+[^.]|^)$');
+final RegExp _allowedTrailingPatterns = RegExp(r'([^ ]([^.^!^:][.!:])\)?|: https?://[^ ]+[^.]|^)$');
 final RegExp _bannedQuotePatterns = RegExp(r" '|' |'\.|\('|'\)|`");
 final RegExp _bannedArgumentReferencePatterns = RegExp(r'[^"=]--[^ ]');
 final RegExp _questionablePatterns = RegExp(r'[a-z]\.[A-Z]');