Use --fatal-infos when analyzing on CI (#184)

Fix some lints.
diff --git a/.github/workflows/test-package.yml b/.github/workflows/test-package.yml
index 8bc4bac..6b79b39 100644
--- a/.github/workflows/test-package.yml
+++ b/.github/workflows/test-package.yml
@@ -32,7 +32,7 @@
         if: always() && steps.install.outcome == 'success'
         run: dart format --output=none --set-exit-if-changed .
       - name: Analyze code
-        run: dart analyze
+        run: dart analyze --fatal-infos
         if: always() && steps.install.outcome == 'success'
 
   # Run tests on a matrix consisting of three dimensions:
diff --git a/lib/src/usage.dart b/lib/src/usage.dart
index 8b788c5..d37a2f2 100644
--- a/lib/src/usage.dart
+++ b/lib/src/usage.dart
@@ -153,7 +153,8 @@
       abbr = math.max(abbr, _abbreviation(option).length);
 
       // Make room for the option.
-      title = math.max(title, _longOption(option).length + _mandatoryOption(option).length);
+      title = math.max(
+          title, _longOption(option).length + _mandatoryOption(option).length);
 
       // Make room for the allowed help.
       if (option.allowedHelp != null) {
diff --git a/test/allow_anything_test.dart b/test/allow_anything_test.dart
index 2addd26..40bb95b 100644
--- a/test/allow_anything_test.dart
+++ b/test/allow_anything_test.dart
@@ -58,7 +58,7 @@
     test('works as a subcommand in a CommandRunner', () async {
       var commandRunner = CommandRunner('command', 'Description of command');
       var command = AllowAnythingCommand();
-      commandRunner..addCommand(command);
+      commandRunner.addCommand(command);
 
       await commandRunner.run([command.name, '--foo', '--bar', '-b', 'qux']);
     });
diff --git a/test/command_parse_test.dart b/test/command_parse_test.dart
index c0a2cf2..fd91470 100644
--- a/test/command_parse_test.dart
+++ b/test/command_parse_test.dart
@@ -190,7 +190,7 @@
 
     test('remaining arguments are given to the innermost command', () {
       var parser = ArgParser();
-      parser.addCommand('cmd')..addCommand('subcmd');
+      parser.addCommand('cmd').addCommand('subcmd');
 
       var args = parser.parse(['cmd', 'subcmd', 'other', 'stuff']);
       expect(args.command!.name, equals('cmd'));
diff --git a/test/usage_test.dart b/test/usage_test.dart
index dbcef78..6999724 100644
--- a/test/usage_test.dart
+++ b/test/usage_test.dart
@@ -5,8 +5,6 @@
 import 'package:args/args.dart';
 import 'package:test/test.dart';
 
-import 'test_utils.dart';
-
 void main() {
   group('ArgParser.usage', () {
     test('negatable flags show "no-" in title', () {
@@ -414,12 +412,12 @@
         ''');
     });
 
-    test('throw argument error if option is mandatory with a default value', () {
+    test('throw argument error if option is mandatory with a default value',
+        () {
       var parser = ArgParser();
       expect(
-        () => parser.addOption('test', mandatory: true, defaultsTo: 'test'),
-        throwsArgumentError
-      );
+          () => parser.addOption('test', mandatory: true, defaultsTo: 'test'),
+          throwsArgumentError);
     });
 
     group('separators', () {