From 49b42177210994230703961c2dca58f758cfcfdf Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E3=81=B5=E3=81=81?= <yuki@yuki0311.com>
Date: Fri, 13 Sep 2024 11:51:37 +0900
Subject: [PATCH 01/13] Add source when throwing format exception
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Signed-off-by: ふぁ <yuki@yuki0311.com>
---
 lib/src/arg_parser_exception.dart |  2 +-
 lib/src/parser.dart               | 50 ++++++++++++++++++-------------
 2 files changed, 30 insertions(+), 22 deletions(-)

diff --git a/lib/src/arg_parser_exception.dart b/lib/src/arg_parser_exception.dart
index d727d70..078d355 100644
--- a/lib/src/arg_parser_exception.dart
+++ b/lib/src/arg_parser_exception.dart
@@ -9,6 +9,6 @@ class ArgParserException extends FormatException {
   /// This will be empty if the error was on the root parser.
   final List<String> commands;
 
-  ArgParserException(super.message, [Iterable<String>? commands])
+  ArgParserException(super.message, super.source, [Iterable<String>? commands])
       : commands = commands == null ? const [] : List.unmodifiable(commands);
 }
diff --git a/lib/src/parser.dart b/lib/src/parser.dart
index 3c5dfed..935aacf 100644
--- a/lib/src/parser.dart
+++ b/lib/src/parser.dart
@@ -63,7 +63,8 @@ class Parser {
       // options so that commands can have option-like names.
       var command = _grammar.commands[_current];
       if (command != null) {
-        _validate(_rest.isEmpty, 'Cannot specify arguments before a command.');
+        _validate(_rest.isEmpty, 'Cannot specify arguments before a command.',
+            _current);
         var commandName = _args.removeFirst();
         var commandParser = Parser(commandName, command, _args, this, _rest);
 
@@ -71,7 +72,7 @@ class Parser {
           commandResults = commandParser.parse();
         } on ArgParserException catch (error) {
           throw ArgParserException(
-              error.message, [commandName, ...error.commands]);
+              error.message, error.source, [commandName, ...error.commands]);
         }
 
         // All remaining arguments were passed to command so clear them here.
@@ -101,7 +102,7 @@ class Parser {
       // Check if an option is mandatory and was passed; if not, throw an
       // exception.
       if (option.mandatory && parsedOption == null) {
-        throw ArgParserException('Option $name is mandatory.');
+        throw ArgParserException('Option $name is mandatory.', name);
       }
 
       // ignore: avoid_dynamic_calls
@@ -120,7 +121,8 @@ class Parser {
   /// Validates that there is a valid value there.
   void _readNextArgAsValue(Option option) {
     // Take the option argument from the next command line arg.
-    _validate(_args.isNotEmpty, 'Missing argument for "${option.name}".');
+    _validate(_args.isNotEmpty, 'Missing argument for "${option.name}".',
+        option.name);
 
     _setOption(_results, option, _current);
     _args.removeFirst();
@@ -145,7 +147,8 @@ class Parser {
     var option = _grammar.findByAbbreviation(opt);
     if (option == null) {
       // Walk up to the parent command if possible.
-      _validate(_parent != null, 'Could not find an option or flag "-$opt".');
+      _validate(_parent != null, 'Could not find an option or flag "-$opt".',
+          '-$opt');
       return _parent!._handleSoloOption(opt);
     }
 
@@ -193,8 +196,8 @@ class Parser {
     var first = _grammar.findByAbbreviation(c);
     if (first == null) {
       // Walk up to the parent command if possible.
-      _validate(
-          _parent != null, 'Could not find an option with short name "-$c".');
+      _validate(_parent != null,
+          'Could not find an option with short name "-$c".', '-$c');
       return _parent!
           ._handleAbbreviation(lettersAndDigits, rest, innermostCommand);
     } else if (!first.isFlag) {
@@ -208,7 +211,8 @@ class Parser {
       _validate(
           rest == '',
           'Option "-$c" is a flag and cannot handle value '
-          '"${lettersAndDigits.substring(1)}$rest".');
+              '"${lettersAndDigits.substring(1)}$rest".',
+          '-$c');
 
       // Not an option, so all characters should be flags.
       // We use "innermostCommand" here so that if a parent command parses the
@@ -228,16 +232,16 @@ class Parser {
     var option = _grammar.findByAbbreviation(c);
     if (option == null) {
       // Walk up to the parent command if possible.
-      _validate(
-          _parent != null, 'Could not find an option with short name "-$c".');
+      _validate(_parent != null,
+          'Could not find an option with short name "-$c".', '-$c');
       _parent!._parseShortFlag(c);
       return;
     }
 
     // In a list of short options, only the first can be a non-flag. If
     // we get here we've checked that already.
-    _validate(
-        option.isFlag, 'Option "-$c" must be a flag to be in a collapsed "-".');
+    _validate(option.isFlag,
+        'Option "-$c" must be a flag to be in a collapsed "-".', '-$c');
 
     _setFlag(_results, option, true);
   }
@@ -269,8 +273,8 @@ class Parser {
     if (option != null) {
       _args.removeFirst();
       if (option.isFlag) {
-        _validate(
-            value == null, 'Flag option "$name" should not be given a value.');
+        _validate(value == null,
+            'Flag option "$name" should not be given a value.', name);
 
         _setFlag(_results, option, true);
       } else if (value != null) {
@@ -286,18 +290,20 @@ class Parser {
       option = _grammar.findByNameOrAlias(positiveName);
       if (option == null) {
         // Walk up to the parent command if possible.
-        _validate(_parent != null, 'Could not find an option named "$name".');
+        _validate(
+            _parent != null, 'Could not find an option named "$name".', name);
         return _parent!._handleLongOption(name, value);
       }
 
       _args.removeFirst();
-      _validate(option.isFlag, 'Cannot negate non-flag option "$name".');
-      _validate(option.negatable!, 'Cannot negate option "$name".');
+      _validate(option.isFlag, 'Cannot negate non-flag option "$name".', name);
+      _validate(option.negatable!, 'Cannot negate option "$name".', name);
 
       _setFlag(_results, option, false);
     } else {
       // Walk up to the parent command if possible.
-      _validate(_parent != null, 'Could not find an option named "$name".');
+      _validate(
+          _parent != null, 'Could not find an option named "$name".', name);
       return _parent!._handleLongOption(name, value);
     }
 
@@ -307,8 +313,10 @@ class Parser {
   /// Called during parsing to validate the arguments.
   ///
   /// Throws an [ArgParserException] if [condition] is `false`.
-  void _validate(bool condition, String message) {
-    if (!condition) throw ArgParserException(message);
+  void _validate(bool condition, String message, String source) {
+    if (!condition) {
+      throw ArgParserException(message, source);
+    }
   }
 
   /// Validates and stores [value] as the value for [option], which must not be
@@ -347,7 +355,7 @@ class Parser {
     if (option.allowed == null) return;
 
     _validate(option.allowed!.contains(value),
-        '"$value" is not an allowed value for option "${option.name}".');
+        '"$value" is not an allowed value for option "${option.name}".', value);
   }
 }
 

From 68fee373e8f502c28e5cea1140810b8f8ea0f513 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E3=81=B5=E3=81=81?= <yuki@yuki0311.com>
Date: Fri, 13 Sep 2024 11:55:41 +0900
Subject: [PATCH 02/13] update CHANGELOG
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Signed-off-by: ふぁ <yuki@yuki0311.com>
---
 CHANGELOG.md | 1 +
 1 file changed, 1 insertion(+)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 8e572ec..27c98f7 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,6 @@
 ## 2.5.1-wip
 
+* Added source argument when throwing a `ArgParserException`.
 * Require Dart 3.3
 
 ## 2.5.0

From 8de726bfa14963261215ee890a6bd662e22d894f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E3=81=B5=E3=81=81?= <yuki@yuki0311.com>
Date: Sat, 14 Sep 2024 23:58:51 +0900
Subject: [PATCH 03/13] update parameter in a backward-compatible way
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Signed-off-by: ふぁ <yuki@yuki0311.com>
---
 lib/src/arg_parser_exception.dart |  3 ++-
 lib/src/parser.dart               | 11 ++++++-----
 2 files changed, 8 insertions(+), 6 deletions(-)

diff --git a/lib/src/arg_parser_exception.dart b/lib/src/arg_parser_exception.dart
index 078d355..8e25277 100644
--- a/lib/src/arg_parser_exception.dart
+++ b/lib/src/arg_parser_exception.dart
@@ -9,6 +9,7 @@ class ArgParserException extends FormatException {
   /// This will be empty if the error was on the root parser.
   final List<String> commands;
 
-  ArgParserException(super.message, super.source, [Iterable<String>? commands])
+  ArgParserException(super.message,
+      [Iterable<String>? commands, super.source, super.offset])
       : commands = commands == null ? const [] : List.unmodifiable(commands);
 }
diff --git a/lib/src/parser.dart b/lib/src/parser.dart
index 935aacf..25bb1a2 100644
--- a/lib/src/parser.dart
+++ b/lib/src/parser.dart
@@ -71,8 +71,8 @@ class Parser {
         try {
           commandResults = commandParser.parse();
         } on ArgParserException catch (error) {
-          throw ArgParserException(
-              error.message, error.source, [commandName, ...error.commands]);
+          throw ArgParserException(error.message,
+              [commandName, ...error.commands], error.source, error.offset);
         }
 
         // All remaining arguments were passed to command so clear them here.
@@ -102,7 +102,7 @@ class Parser {
       // Check if an option is mandatory and was passed; if not, throw an
       // exception.
       if (option.mandatory && parsedOption == null) {
-        throw ArgParserException('Option $name is mandatory.', name);
+        throw ArgParserException('Option $name is mandatory.', null, name);
       }
 
       // ignore: avoid_dynamic_calls
@@ -313,9 +313,10 @@ class Parser {
   /// Called during parsing to validate the arguments.
   ///
   /// Throws an [ArgParserException] if [condition] is `false`.
-  void _validate(bool condition, String message, String source) {
+  void _validate(bool condition, String message,
+      [dynamic source, int? offset]) {
     if (!condition) {
-      throw ArgParserException(message, source);
+      throw ArgParserException(message, null, source, offset);
     }
   }
 

From fa6838b370a118dcecf6e12aeec7cc6e8b13b31f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E3=81=B5=E3=81=81?= <yuki@yuki0311.com>
Date: Sun, 15 Sep 2024 01:04:17 +0900
Subject: [PATCH 04/13] chore clean up test code
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Signed-off-by: ふぁ <yuki@yuki0311.com>
---
 test/command_parse_test.dart    |  6 +++---
 test/parse_test.dart            | 24 ++++++++++++------------
 test/test_utils.dart            |  6 ++++--
 test/trailing_options_test.dart |  4 +++-
 4 files changed, 22 insertions(+), 18 deletions(-)

diff --git a/test/command_parse_test.dart b/test/command_parse_test.dart
index b6437c1..cfab871 100644
--- a/test/command_parse_test.dart
+++ b/test/command_parse_test.dart
@@ -139,7 +139,7 @@ void main() {
       var command = parser.addCommand('install');
       command.addOption('path', abbr: 'p');
 
-      throwsFormat(parser, ['-p', 'foo', 'install']);
+      throwsArgParserException(parser, ['-p', 'foo', 'install']);
     });
 
     test('does not parse a command option before the command', () {
@@ -147,7 +147,7 @@ void main() {
       var command = parser.addCommand('install');
       command.addOption('path');
 
-      throwsFormat(parser, ['--path', 'foo', 'install']);
+      throwsArgParserException(parser, ['--path', 'foo', 'install']);
     });
 
     test('does not parse a command abbreviation before the command', () {
@@ -156,7 +156,7 @@ void main() {
       command.addFlag('debug', abbr: 'd');
       command.addFlag('verbose', abbr: 'v');
 
-      throwsFormat(parser, ['-dv', 'install']);
+      throwsArgParserException(parser, ['-dv', 'install']);
     });
 
     test('assigns collapsed options to the proper command', () {
diff --git a/test/parse_test.dart b/test/parse_test.dart
index b2dda44..bc0b517 100644
--- a/test/parse_test.dart
+++ b/test/parse_test.dart
@@ -50,7 +50,7 @@ void main() {
         var parser = ArgParser();
         parser.addFlag('verbose');
 
-        throwsFormat(parser, ['--verbose=true']);
+        throwsArgParserException(parser, ['--verbose=true']);
       });
 
       test('are case-sensitive', () {
@@ -189,7 +189,7 @@ void main() {
         var parser = ArgParser();
         parser.addFlag('strum', negatable: false);
 
-        throwsFormat(parser, ['--no-strum']);
+        throwsArgParserException(parser, ['--no-strum']);
       });
     });
 
@@ -399,14 +399,14 @@ void main() {
 
       test('throw if unknown', () {
         var parser = ArgParser();
-        throwsFormat(parser, ['-f']);
+        throwsArgParserException(parser, ['-f']);
       });
 
       test('throw if the value is missing', () {
         var parser = ArgParser();
         parser.addOption('file', abbr: 'f');
 
-        throwsFormat(parser, ['-f']);
+        throwsArgParserException(parser, ['-f']);
       });
 
       test('does not throw if the value looks like an option', () {
@@ -424,7 +424,7 @@ void main() {
         var parser = ArgParser();
         parser.addOption('mode', abbr: 'm', allowed: ['debug', 'release']);
 
-        throwsFormat(parser, ['-mprofile']);
+        throwsArgParserException(parser, ['-mprofile']);
       });
 
       group('throw if a comma-separated value is not allowed', () {
@@ -433,7 +433,7 @@ void main() {
           parser
               .addMultiOption('mode', abbr: 'm', allowed: ['debug', 'release']);
 
-          throwsFormat(parser, ['-mdebug,profile']);
+          throwsArgParserException(parser, ['-mdebug,profile']);
         });
       });
 
@@ -443,7 +443,7 @@ void main() {
         parser.addOption('banana', abbr: 'b'); // Takes an argument.
         parser.addFlag('cherry', abbr: 'c');
 
-        throwsFormat(parser, ['-abc']);
+        throwsArgParserException(parser, ['-abc']);
       });
 
       test('throw if it has a value but the option is a flag', () {
@@ -452,7 +452,7 @@ void main() {
         parser.addFlag('banana', abbr: 'b');
 
         // The '?!' means this can only be understood as '--apple b?!c'.
-        throwsFormat(parser, ['-ab?!c']);
+        throwsArgParserException(parser, ['-ab?!c']);
       });
 
       test('are case-sensitive', () {
@@ -496,14 +496,14 @@ void main() {
 
       test('throw if unknown', () {
         var parser = ArgParser();
-        throwsFormat(parser, ['--unknown']);
-        throwsFormat(parser, ['--nobody']); // Starts with "no".
+        throwsArgParserException(parser, ['--unknown']);
+        throwsArgParserException(parser, ['--nobody']); // Starts with "no".
       });
 
       test('throw if the arg does not include a value', () {
         var parser = ArgParser();
         parser.addOption('mode');
-        throwsFormat(parser, ['--mode']);
+        throwsArgParserException(parser, ['--mode']);
       });
 
       test('do not throw if the value looks like an option', () {
@@ -538,7 +538,7 @@ void main() {
       test('throw if the value is not in the allowed set', () {
         var parser = ArgParser();
         parser.addOption('mode', allowed: ['debug', 'release']);
-        throwsFormat(parser, ['--mode=profile']);
+        throwsArgParserException(parser, ['--mode=profile']);
       });
 
       test('returns last provided value', () {
diff --git a/test/test_utils.dart b/test/test_utils.dart
index f19da6d..9e4a22e 100644
--- a/test/test_utils.dart
+++ b/test/test_utils.dart
@@ -343,8 +343,10 @@ void throwsIllegalArg(void Function() function, {String? reason}) {
   expect(function, throwsArgumentError, reason: reason);
 }
 
-void throwsFormat(ArgParser parser, List<String> args) {
-  expect(() => parser.parse(args), throwsFormatException);
+void throwsArgParserException(ArgParser parser, List<String> args,
+    {String? reason}) {
+  expect(() => parser.parse(args), throwsA(isA<ArgParserException>()),
+      reason: reason);
 }
 
 Matcher throwsUsageException(Object? message, Object? usage) =>
diff --git a/test/trailing_options_test.dart b/test/trailing_options_test.dart
index 505b6b1..0580090 100644
--- a/test/trailing_options_test.dart
+++ b/test/trailing_options_test.dart
@@ -5,6 +5,8 @@
 import 'package:args/args.dart';
 import 'package:test/test.dart';
 
+import 'test_utils.dart';
+
 void main() {
   test('allowTrailingOptions defaults to true', () {
     var parser = ArgParser();
@@ -18,7 +20,7 @@ void main() {
     });
 
     void expectThrows(List<String> args) {
-      expect(() => parser.parse(args), throwsFormatException,
+      throwsArgParserException(parser, args,
           reason: 'with allowTrailingOptions: true');
     }
 

From 7859972c7e0727db1b80ba421373440c9f0c3b48 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E3=81=B5=E3=81=81?= <yuki@yuki0311.com>
Date: Sun, 15 Sep 2024 02:42:49 +0900
Subject: [PATCH 05/13] fix inconsistent `FormatException` messages
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Signed-off-by: ふぁ <yuki@yuki0311.com>
---
 lib/src/arg_results.dart        | 10 ++++----
 lib/src/parser.dart             | 43 +++++++++++++++++----------------
 test/command_parse_test.dart    |  6 ++---
 test/command_runner_test.dart   | 10 ++++----
 test/parse_test.dart            | 25 ++++++++++---------
 test/test_utils.dart            | 13 +++++++---
 test/trailing_options_test.dart | 12 ++++-----
 7 files changed, 64 insertions(+), 55 deletions(-)

diff --git a/lib/src/arg_results.dart b/lib/src/arg_results.dart
index 9fa87cd..72c4410 100644
--- a/lib/src/arg_results.dart
+++ b/lib/src/arg_results.dart
@@ -66,7 +66,7 @@ class ArgResults {
   /// > flags, [option] for options, and [multiOption] for multi-options.
   dynamic operator [](String name) {
     if (!_parser.options.containsKey(name)) {
-      throw ArgumentError('Could not find an option named "$name".');
+      throw ArgumentError('Could not find an option named "--$name".');
     }
 
     final option = _parser.options[name]!;
@@ -83,7 +83,7 @@ class ArgResults {
   bool flag(String name) {
     var option = _parser.options[name];
     if (option == null) {
-      throw ArgumentError('Could not find an option named "$name".');
+      throw ArgumentError('Could not find an option named "--$name".');
     }
     if (!option.isFlag) {
       throw ArgumentError('"$name" is not a flag.');
@@ -97,7 +97,7 @@ class ArgResults {
   String? option(String name) {
     var option = _parser.options[name];
     if (option == null) {
-      throw ArgumentError('Could not find an option named "$name".');
+      throw ArgumentError('Could not find an option named "--$name".');
     }
     if (!option.isSingle) {
       throw ArgumentError('"$name" is a multi-option.');
@@ -111,7 +111,7 @@ class ArgResults {
   List<String> multiOption(String name) {
     var option = _parser.options[name];
     if (option == null) {
-      throw ArgumentError('Could not find an option named "$name".');
+      throw ArgumentError('Could not find an option named "--$name".');
     }
     if (!option.isMultiple) {
       throw ArgumentError('"$name" is not a multi-option.');
@@ -143,7 +143,7 @@ class ArgResults {
   /// [name] must be a valid option name in the parser.
   bool wasParsed(String name) {
     if (!_parser.options.containsKey(name)) {
-      throw ArgumentError('Could not find an option named "$name".');
+      throw ArgumentError('Could not find an option named "--$name".');
     }
 
     return _parsed.containsKey(name);
diff --git a/lib/src/parser.dart b/lib/src/parser.dart
index 25bb1a2..24c7fb1 100644
--- a/lib/src/parser.dart
+++ b/lib/src/parser.dart
@@ -119,12 +119,11 @@ class Parser {
   /// Pulls the value for [option] from the second argument in [_args].
   ///
   /// Validates that there is a valid value there.
-  void _readNextArgAsValue(Option option) {
+  void _readNextArgAsValue(Option option, String source) {
     // Take the option argument from the next command line arg.
-    _validate(_args.isNotEmpty, 'Missing argument for "${option.name}".',
-        option.name);
+    _validate(_args.isNotEmpty, 'Missing argument for "$source".', source);
 
-    _setOption(_results, option, _current);
+    _setOption(_results, option, _current, source);
     _args.removeFirst();
   }
 
@@ -157,7 +156,7 @@ class Parser {
     if (option.isFlag) {
       _setFlag(_results, option, true);
     } else {
-      _readNextArgAsValue(option);
+      _readNextArgAsValue(option, '-$opt');
     }
 
     return true;
@@ -204,7 +203,7 @@ class Parser {
       // The first character is a non-flag option, so the rest must be the
       // value.
       var value = '${lettersAndDigits.substring(1)}$rest';
-      _setOption(_results, first, value);
+      _setOption(_results, first, value, '-$c');
     } else {
       // If we got some non-flag characters, then it must be a value, but
       // if we got here, it's a flag, which is wrong.
@@ -274,15 +273,15 @@ class Parser {
       _args.removeFirst();
       if (option.isFlag) {
         _validate(value == null,
-            'Flag option "$name" should not be given a value.', name);
+            'Flag option "--$name" should not be given a value.', '--$name');
 
         _setFlag(_results, option, true);
       } else if (value != null) {
         // We have a value like --foo=bar.
-        _setOption(_results, option, value);
+        _setOption(_results, option, value, '--$name');
       } else {
         // Option like --foo, so look for the value as the next arg.
-        _readNextArgAsValue(option);
+        _readNextArgAsValue(option, '--$name');
       }
     } else if (name.startsWith('no-')) {
       // See if it's a negated flag.
@@ -290,20 +289,22 @@ class Parser {
       option = _grammar.findByNameOrAlias(positiveName);
       if (option == null) {
         // Walk up to the parent command if possible.
-        _validate(
-            _parent != null, 'Could not find an option named "$name".', name);
+        _validate(_parent != null, 'Could not find an option named "--$name".',
+            '--$name');
         return _parent!._handleLongOption(name, value);
       }
 
       _args.removeFirst();
-      _validate(option.isFlag, 'Cannot negate non-flag option "$name".', name);
-      _validate(option.negatable!, 'Cannot negate option "$name".', name);
+      _validate(
+          option.isFlag, 'Cannot negate non-flag option "--$name".', '--$name');
+      _validate(
+          option.negatable!, 'Cannot negate option "--$name".', '--$name');
 
       _setFlag(_results, option, false);
     } else {
       // Walk up to the parent command if possible.
-      _validate(
-          _parent != null, 'Could not find an option named "$name".', name);
+      _validate(_parent != null, 'Could not find an option named "--$name".',
+          '--$name');
       return _parent!._handleLongOption(name, value);
     }
 
@@ -322,11 +323,11 @@ class Parser {
 
   /// Validates and stores [value] as the value for [option], which must not be
   /// a flag.
-  void _setOption(Map results, Option option, String value) {
+  void _setOption(Map results, Option option, String value, String source) {
     assert(!option.isFlag);
 
     if (!option.isMultiple) {
-      _validateAllowed(option, value);
+      _validateAllowed(option, value, source);
       results[option.name] = value;
       return;
     }
@@ -335,11 +336,11 @@ class Parser {
 
     if (option.splitCommas) {
       for (var element in value.split(',')) {
-        _validateAllowed(option, element);
+        _validateAllowed(option, element, source);
         list.add(element);
       }
     } else {
-      _validateAllowed(option, value);
+      _validateAllowed(option, value, source);
       list.add(value);
     }
   }
@@ -352,11 +353,11 @@ class Parser {
   }
 
   /// Validates that [value] is allowed as a value of [option].
-  void _validateAllowed(Option option, String value) {
+  void _validateAllowed(Option option, String value, String source) {
     if (option.allowed == null) return;
 
     _validate(option.allowed!.contains(value),
-        '"$value" is not an allowed value for option "${option.name}".', value);
+        '"$value" is not an allowed value for option "$source".', source);
   }
 }
 
diff --git a/test/command_parse_test.dart b/test/command_parse_test.dart
index cfab871..e1b2f11 100644
--- a/test/command_parse_test.dart
+++ b/test/command_parse_test.dart
@@ -139,7 +139,7 @@ void main() {
       var command = parser.addCommand('install');
       command.addOption('path', abbr: 'p');
 
-      throwsArgParserException(parser, ['-p', 'foo', 'install']);
+      throwsArgParserException(parser, ['-p', 'foo', 'install'], '-p');
     });
 
     test('does not parse a command option before the command', () {
@@ -147,7 +147,7 @@ void main() {
       var command = parser.addCommand('install');
       command.addOption('path');
 
-      throwsArgParserException(parser, ['--path', 'foo', 'install']);
+      throwsArgParserException(parser, ['--path', 'foo', 'install'], '--path');
     });
 
     test('does not parse a command abbreviation before the command', () {
@@ -156,7 +156,7 @@ void main() {
       command.addFlag('debug', abbr: 'd');
       command.addFlag('verbose', abbr: 'v');
 
-      throwsArgParserException(parser, ['-dv', 'install']);
+      throwsArgParserException(parser, ['-dv', 'install'], '-d');
     });
 
     test('assigns collapsed options to the proper command', () {
diff --git a/test/command_runner_test.dart b/test/command_runner_test.dart
index cc80c6b..b9fde8a 100644
--- a/test/command_runner_test.dart
+++ b/test/command_runner_test.dart
@@ -583,7 +583,7 @@ Run "test help" to see global options.
         expect(
             runner.run(['--asdf']),
             throwsUsageException(
-                'Could not find an option named "asdf".', _defaultUsage));
+                'Could not find an option named "--asdf".', _defaultUsage));
       });
 
       test('for a command throws the command usage', () {
@@ -591,7 +591,7 @@ Run "test help" to see global options.
         runner.addCommand(command);
 
         expect(runner.run(['foo', '--asdf']),
-            throwsUsageException('Could not find an option named "asdf".', '''
+            throwsUsageException('Could not find an option named "--asdf".', '''
 Usage: test foo [arguments]
 -h, --help    Print this usage information.
 
@@ -616,7 +616,7 @@ Also, footer!'''));
     test('includes the footer in usage errors', () {
       expect(
           runner.run(['--bad']),
-          throwsUsageException('Could not find an option named "bad".',
+          throwsUsageException('Could not find an option named "--bad".',
               '$_defaultUsage\nAlso, footer!'));
     });
   });
@@ -652,7 +652,7 @@ newlines properly.'''));
 
     test('includes the footer in usage errors', () {
       expect(runner.run(['--bad']),
-          throwsUsageException('Could not find an option named "bad".', '''
+          throwsUsageException('Could not find an option named "--bad".', '''
 Usage: test <command> [arguments]
 
 Global options:
@@ -679,7 +679,7 @@ newlines properly.'''));
       expect(
           runner.run(['--bad']),
           throwsUsageException(
-              'Could not find an option named "bad".', _defaultUsage));
+              'Could not find an option named "--bad".', _defaultUsage));
     });
 
     test("a top-level command doesn't exist", () {
diff --git a/test/parse_test.dart b/test/parse_test.dart
index bc0b517..3b41ee9 100644
--- a/test/parse_test.dart
+++ b/test/parse_test.dart
@@ -50,7 +50,7 @@ void main() {
         var parser = ArgParser();
         parser.addFlag('verbose');
 
-        throwsArgParserException(parser, ['--verbose=true']);
+        throwsArgParserException(parser, ['--verbose=true'], '--verbose');
       });
 
       test('are case-sensitive', () {
@@ -189,7 +189,7 @@ void main() {
         var parser = ArgParser();
         parser.addFlag('strum', negatable: false);
 
-        throwsArgParserException(parser, ['--no-strum']);
+        throwsArgParserException(parser, ['--no-strum'], '--no-strum');
       });
     });
 
@@ -399,14 +399,14 @@ void main() {
 
       test('throw if unknown', () {
         var parser = ArgParser();
-        throwsArgParserException(parser, ['-f']);
+        throwsArgParserException(parser, ['-f'], '-f');
       });
 
       test('throw if the value is missing', () {
         var parser = ArgParser();
         parser.addOption('file', abbr: 'f');
 
-        throwsArgParserException(parser, ['-f']);
+        throwsArgParserException(parser, ['-f'], '-f');
       });
 
       test('does not throw if the value looks like an option', () {
@@ -424,7 +424,7 @@ void main() {
         var parser = ArgParser();
         parser.addOption('mode', abbr: 'm', allowed: ['debug', 'release']);
 
-        throwsArgParserException(parser, ['-mprofile']);
+        throwsArgParserException(parser, ['-mprofile'], '-m');
       });
 
       group('throw if a comma-separated value is not allowed', () {
@@ -433,7 +433,7 @@ void main() {
           parser
               .addMultiOption('mode', abbr: 'm', allowed: ['debug', 'release']);
 
-          throwsArgParserException(parser, ['-mdebug,profile']);
+          throwsArgParserException(parser, ['-mdebug,profile'], '-m');
         });
       });
 
@@ -443,7 +443,7 @@ void main() {
         parser.addOption('banana', abbr: 'b'); // Takes an argument.
         parser.addFlag('cherry', abbr: 'c');
 
-        throwsArgParserException(parser, ['-abc']);
+        throwsArgParserException(parser, ['-abc'], '-b');
       });
 
       test('throw if it has a value but the option is a flag', () {
@@ -452,7 +452,7 @@ void main() {
         parser.addFlag('banana', abbr: 'b');
 
         // The '?!' means this can only be understood as '--apple b?!c'.
-        throwsArgParserException(parser, ['-ab?!c']);
+        throwsArgParserException(parser, ['-ab?!c'], '-a');
       });
 
       test('are case-sensitive', () {
@@ -496,14 +496,15 @@ void main() {
 
       test('throw if unknown', () {
         var parser = ArgParser();
-        throwsArgParserException(parser, ['--unknown']);
-        throwsArgParserException(parser, ['--nobody']); // Starts with "no".
+        throwsArgParserException(parser, ['--unknown'], '--unknown');
+        throwsArgParserException(
+            parser, ['--nobody'], '--nobody'); // Starts with "no".
       });
 
       test('throw if the arg does not include a value', () {
         var parser = ArgParser();
         parser.addOption('mode');
-        throwsArgParserException(parser, ['--mode']);
+        throwsArgParserException(parser, ['--mode'], '--mode');
       });
 
       test('do not throw if the value looks like an option', () {
@@ -538,7 +539,7 @@ void main() {
       test('throw if the value is not in the allowed set', () {
         var parser = ArgParser();
         parser.addOption('mode', allowed: ['debug', 'release']);
-        throwsArgParserException(parser, ['--mode=profile']);
+        throwsArgParserException(parser, ['--mode=profile'], '--mode');
       });
 
       test('returns last provided value', () {
diff --git a/test/test_utils.dart b/test/test_utils.dart
index 9e4a22e..9b67e9a 100644
--- a/test/test_utils.dart
+++ b/test/test_utils.dart
@@ -343,10 +343,17 @@ void throwsIllegalArg(void Function() function, {String? reason}) {
   expect(function, throwsArgumentError, reason: reason);
 }
 
-void throwsArgParserException(ArgParser parser, List<String> args,
+void throwsArgParserException(
+    ArgParser parser, List<String> args, String? source,
     {String? reason}) {
-  expect(() => parser.parse(args), throwsA(isA<ArgParserException>()),
-      reason: reason);
+  try {
+    parser.parse(args);
+    fail('Expected an ArgParserException');
+  } on ArgParserException catch (e) {
+    expect(e.source, source);
+  } catch (e) {
+    fail('Expected an ArgParserException, but got $e');
+  }
 }
 
 Matcher throwsUsageException(Object? message, Object? usage) =>
diff --git a/test/trailing_options_test.dart b/test/trailing_options_test.dart
index 0580090..0cd4e68 100644
--- a/test/trailing_options_test.dart
+++ b/test/trailing_options_test.dart
@@ -19,8 +19,8 @@ void main() {
       parser = ArgParser(allowTrailingOptions: true);
     });
 
-    void expectThrows(List<String> args) {
-      throwsArgParserException(parser, args,
+    void expectThrows(List<String> args, String source) {
+      throwsArgParserException(parser, args, source,
           reason: 'with allowTrailingOptions: true');
     }
 
@@ -58,7 +58,7 @@ void main() {
 
     test('throws on a trailing option missing its value', () {
       parser.addOption('opt');
-      expectThrows(['arg', '--opt']);
+      expectThrows(['arg', '--opt'], '--opt');
     });
 
     test('parses a trailing option', () {
@@ -69,16 +69,16 @@ void main() {
     });
 
     test('throws on a trailing unknown flag', () {
-      expectThrows(['arg', '--xflag']);
+      expectThrows(['arg', '--xflag'], '--xflag');
     });
 
     test('throws on a trailing unknown option and value', () {
-      expectThrows(['arg', '--xopt', 'v']);
+      expectThrows(['arg', '--xopt', 'v'], '--xopt');
     });
 
     test('throws on a command', () {
       parser.addCommand('com');
-      expectThrows(['arg', 'com']);
+      expectThrows(['arg', 'com'], 'com');
     });
   });
 

From 4be08f6a569c556081c6ccb6a3b1cf53e82f543c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E3=81=B5=E3=81=81?= <yuki@yuki0311.com>
Date: Sun, 15 Sep 2024 02:44:00 +0900
Subject: [PATCH 06/13] update CHANGELOG
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Signed-off-by: ふぁ <yuki@yuki0311.com>
---
 CHANGELOG.md | 1 +
 1 file changed, 1 insertion(+)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 27c98f7..26f4c5c 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,6 +1,7 @@
 ## 2.5.1-wip
 
 * Added source argument when throwing a `ArgParserException`.
+* Fix inconsistent `FormatException` messages
 * Require Dart 3.3
 
 ## 2.5.0

From 7550d120cab612a18a75e62a2722d8cfe937e9bc Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E3=81=B5=E3=81=81?= <yuki@yuki0311.com>
Date: Wed, 25 Sep 2024 10:19:21 +0900
Subject: [PATCH 07/13] update: rename source to arg
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Signed-off-by: ふぁ <yuki@yuki0311.com>
---
 lib/src/arg_parser_exception.dart |  5 ++++-
 lib/src/parser.dart               | 30 +++++++++++++++++-------------
 test/test_utils.dart              |  5 ++---
 test/trailing_options_test.dart   |  4 ++--
 4 files changed, 25 insertions(+), 19 deletions(-)

diff --git a/lib/src/arg_parser_exception.dart b/lib/src/arg_parser_exception.dart
index 8e25277..dda5366 100644
--- a/lib/src/arg_parser_exception.dart
+++ b/lib/src/arg_parser_exception.dart
@@ -9,7 +9,10 @@ class ArgParserException extends FormatException {
   /// This will be empty if the error was on the root parser.
   final List<String> commands;
 
+  /// The argument that were being parsed when the error was discovered.
+  final String? arg;
+
   ArgParserException(super.message,
-      [Iterable<String>? commands, super.source, super.offset])
+      [Iterable<String>? commands, this.arg, super.source, super.offset])
       : commands = commands == null ? const [] : List.unmodifiable(commands);
 }
diff --git a/lib/src/parser.dart b/lib/src/parser.dart
index 24c7fb1..354ed2f 100644
--- a/lib/src/parser.dart
+++ b/lib/src/parser.dart
@@ -71,8 +71,12 @@ class Parser {
         try {
           commandResults = commandParser.parse();
         } on ArgParserException catch (error) {
-          throw ArgParserException(error.message,
-              [commandName, ...error.commands], error.source, error.offset);
+          throw ArgParserException(
+              error.message,
+              [commandName, ...error.commands],
+              error.arg,
+              error.source,
+              error.offset);
         }
 
         // All remaining arguments were passed to command so clear them here.
@@ -119,11 +123,11 @@ class Parser {
   /// Pulls the value for [option] from the second argument in [_args].
   ///
   /// Validates that there is a valid value there.
-  void _readNextArgAsValue(Option option, String source) {
+  void _readNextArgAsValue(Option option, String arg) {
     // Take the option argument from the next command line arg.
-    _validate(_args.isNotEmpty, 'Missing argument for "$source".', source);
+    _validate(_args.isNotEmpty, 'Missing argument for "$arg".', arg);
 
-    _setOption(_results, option, _current, source);
+    _setOption(_results, option, _current, arg);
     _args.removeFirst();
   }
 
@@ -315,19 +319,19 @@ class Parser {
   ///
   /// Throws an [ArgParserException] if [condition] is `false`.
   void _validate(bool condition, String message,
-      [dynamic source, int? offset]) {
+      [String? args, List<String>? source, int? offset]) {
     if (!condition) {
-      throw ArgParserException(message, null, source, offset);
+      throw ArgParserException(message, null, args, source, offset);
     }
   }
 
   /// Validates and stores [value] as the value for [option], which must not be
   /// a flag.
-  void _setOption(Map results, Option option, String value, String source) {
+  void _setOption(Map results, Option option, String value, String arg) {
     assert(!option.isFlag);
 
     if (!option.isMultiple) {
-      _validateAllowed(option, value, source);
+      _validateAllowed(option, value, arg);
       results[option.name] = value;
       return;
     }
@@ -336,11 +340,11 @@ class Parser {
 
     if (option.splitCommas) {
       for (var element in value.split(',')) {
-        _validateAllowed(option, element, source);
+        _validateAllowed(option, element, arg);
         list.add(element);
       }
     } else {
-      _validateAllowed(option, value, source);
+      _validateAllowed(option, value, arg);
       list.add(value);
     }
   }
@@ -353,11 +357,11 @@ class Parser {
   }
 
   /// Validates that [value] is allowed as a value of [option].
-  void _validateAllowed(Option option, String value, String source) {
+  void _validateAllowed(Option option, String value, String arg) {
     if (option.allowed == null) return;
 
     _validate(option.allowed!.contains(value),
-        '"$value" is not an allowed value for option "$source".', source);
+        '"$value" is not an allowed value for option "$arg".', arg);
   }
 }
 
diff --git a/test/test_utils.dart b/test/test_utils.dart
index 9b67e9a..f1680cf 100644
--- a/test/test_utils.dart
+++ b/test/test_utils.dart
@@ -343,14 +343,13 @@ void throwsIllegalArg(void Function() function, {String? reason}) {
   expect(function, throwsArgumentError, reason: reason);
 }
 
-void throwsArgParserException(
-    ArgParser parser, List<String> args, String? source,
+void throwsArgParserException(ArgParser parser, List<String> args, String? arg,
     {String? reason}) {
   try {
     parser.parse(args);
     fail('Expected an ArgParserException');
   } on ArgParserException catch (e) {
-    expect(e.source, source);
+    expect(e.arg, arg);
   } catch (e) {
     fail('Expected an ArgParserException, but got $e');
   }
diff --git a/test/trailing_options_test.dart b/test/trailing_options_test.dart
index 0cd4e68..fb6bba0 100644
--- a/test/trailing_options_test.dart
+++ b/test/trailing_options_test.dart
@@ -19,8 +19,8 @@ void main() {
       parser = ArgParser(allowTrailingOptions: true);
     });
 
-    void expectThrows(List<String> args, String source) {
-      throwsArgParserException(parser, args, source,
+    void expectThrows(List<String> args, String arg) {
+      throwsArgParserException(parser, args, arg,
           reason: 'with allowTrailingOptions: true');
     }
 

From fd5e80339f93434064e69b699633b1b8a7f36f66 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E3=81=B5=E3=81=81?= <yuki@yuki0311.com>
Date: Wed, 25 Sep 2024 12:36:55 +0900
Subject: [PATCH 08/13] add test and cleanup test
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Signed-off-by: ふぁ <yuki@yuki0311.com>
---
 test/command_parse_test.dart    |  6 +--
 test/parse_test.dart            | 74 +++++++++++++++++++++++++++------
 test/test_utils.dart            | 11 ++++-
 test/trailing_options_test.dart |  3 +-
 4 files changed, 74 insertions(+), 20 deletions(-)

diff --git a/test/command_parse_test.dart b/test/command_parse_test.dart
index e1b2f11..b6437c1 100644
--- a/test/command_parse_test.dart
+++ b/test/command_parse_test.dart
@@ -139,7 +139,7 @@ void main() {
       var command = parser.addCommand('install');
       command.addOption('path', abbr: 'p');
 
-      throwsArgParserException(parser, ['-p', 'foo', 'install'], '-p');
+      throwsFormat(parser, ['-p', 'foo', 'install']);
     });
 
     test('does not parse a command option before the command', () {
@@ -147,7 +147,7 @@ void main() {
       var command = parser.addCommand('install');
       command.addOption('path');
 
-      throwsArgParserException(parser, ['--path', 'foo', 'install'], '--path');
+      throwsFormat(parser, ['--path', 'foo', 'install']);
     });
 
     test('does not parse a command abbreviation before the command', () {
@@ -156,7 +156,7 @@ void main() {
       command.addFlag('debug', abbr: 'd');
       command.addFlag('verbose', abbr: 'v');
 
-      throwsArgParserException(parser, ['-dv', 'install'], '-d');
+      throwsFormat(parser, ['-dv', 'install']);
     });
 
     test('assigns collapsed options to the proper command', () {
diff --git a/test/parse_test.dart b/test/parse_test.dart
index 3b41ee9..9501b5d 100644
--- a/test/parse_test.dart
+++ b/test/parse_test.dart
@@ -50,7 +50,7 @@ void main() {
         var parser = ArgParser();
         parser.addFlag('verbose');
 
-        throwsArgParserException(parser, ['--verbose=true'], '--verbose');
+        throwsFormat(parser, ['--verbose=true']);
       });
 
       test('are case-sensitive', () {
@@ -189,7 +189,7 @@ void main() {
         var parser = ArgParser();
         parser.addFlag('strum', negatable: false);
 
-        throwsArgParserException(parser, ['--no-strum'], '--no-strum');
+        throwsFormat(parser, ['--no-strum']);
       });
     });
 
@@ -399,14 +399,14 @@ void main() {
 
       test('throw if unknown', () {
         var parser = ArgParser();
-        throwsArgParserException(parser, ['-f'], '-f');
+        throwsFormat(parser, ['-f']);
       });
 
       test('throw if the value is missing', () {
         var parser = ArgParser();
         parser.addOption('file', abbr: 'f');
 
-        throwsArgParserException(parser, ['-f'], '-f');
+        throwsFormat(parser, ['-f']);
       });
 
       test('does not throw if the value looks like an option', () {
@@ -424,7 +424,7 @@ void main() {
         var parser = ArgParser();
         parser.addOption('mode', abbr: 'm', allowed: ['debug', 'release']);
 
-        throwsArgParserException(parser, ['-mprofile'], '-m');
+        throwsFormat(parser, ['-mprofile']);
       });
 
       group('throw if a comma-separated value is not allowed', () {
@@ -433,7 +433,7 @@ void main() {
           parser
               .addMultiOption('mode', abbr: 'm', allowed: ['debug', 'release']);
 
-          throwsArgParserException(parser, ['-mdebug,profile'], '-m');
+          throwsFormat(parser, ['-mdebug,profile']);
         });
       });
 
@@ -443,7 +443,7 @@ void main() {
         parser.addOption('banana', abbr: 'b'); // Takes an argument.
         parser.addFlag('cherry', abbr: 'c');
 
-        throwsArgParserException(parser, ['-abc'], '-b');
+        throwsFormat(parser, ['-abc']);
       });
 
       test('throw if it has a value but the option is a flag', () {
@@ -452,7 +452,7 @@ void main() {
         parser.addFlag('banana', abbr: 'b');
 
         // The '?!' means this can only be understood as '--apple b?!c'.
-        throwsArgParserException(parser, ['-ab?!c'], '-a');
+        throwsFormat(parser, ['-ab?!c']);
       });
 
       test('are case-sensitive', () {
@@ -496,15 +496,14 @@ void main() {
 
       test('throw if unknown', () {
         var parser = ArgParser();
-        throwsArgParserException(parser, ['--unknown'], '--unknown');
-        throwsArgParserException(
-            parser, ['--nobody'], '--nobody'); // Starts with "no".
+        throwsFormat(parser, ['--unknown']);
+        throwsFormat(parser, ['--nobody']); // Starts with "no".
       });
 
       test('throw if the arg does not include a value', () {
         var parser = ArgParser();
         parser.addOption('mode');
-        throwsArgParserException(parser, ['--mode'], '--mode');
+        throwsFormat(parser, ['--mode']);
       });
 
       test('do not throw if the value looks like an option', () {
@@ -539,7 +538,7 @@ void main() {
       test('throw if the value is not in the allowed set', () {
         var parser = ArgParser();
         parser.addOption('mode', allowed: ['debug', 'release']);
-        throwsArgParserException(parser, ['--mode=profile'], '--mode');
+        throwsFormat(parser, ['--mode=profile']);
       });
 
       test('returns last provided value', () {
@@ -767,5 +766,54 @@ void main() {
         expect(results.rest, equals(['stop', '--', 'arg']));
       });
     });
+
+    group('ArgParser Exception Tests', () {
+      test('throws exception for unknown option', () {
+        var parser = ArgParser();
+        throwsArgParserException(parser, ['--verbose'],
+            'Could not find an option named "--verbose".', [], '--verbose');
+        throwsArgParserException(
+            parser, ['-v'], 'Could not find an option or flag "-v".', [], '-v');
+      });
+
+      test('throws exception for flag with value', () {
+        var parser = ArgParser();
+        parser.addFlag('flag', abbr: 'f');
+        throwsArgParserException(parser, ['--flag=1'],
+            'Flag option "--flag" should not be given a value.', [], '--flag');
+        throwsArgParserException(parser, ['-f=1'],
+            'Option "-f" is a flag and cannot handle value "=1".', [], '-f');
+      });
+
+      test('throws exception after parsing multiple options', () {
+        var parser = ArgParser();
+        parser.addOption('first');
+        parser.addOption('second');
+        throwsArgParserException(
+            parser,
+            ['--first', '1', '--second', '2', '--verbose', '3'],
+            'Could not find an option named "--verbose".',
+            [],
+            '--verbose');
+      });
+
+      test('throws exception for option with invalid value', () {
+        var parser = ArgParser();
+        parser.addOption('first', allowed: ['a', 'b']);
+        throwsArgParserException(parser, ['--first', 'c'],
+            '"c" is not an allowed value for option "--first".', [], '--first');
+      });
+
+      test('throws exception after parsing command', () {
+        var parser = ArgParser();
+        parser.addCommand('command', ArgParser());
+        throwsArgParserException(
+            parser,
+            ['command', '--verbose'],
+            'Could not find an option named "--verbose".',
+            ['command'],
+            '--verbose');
+      });
+    });
   });
 }
diff --git a/test/test_utils.dart b/test/test_utils.dart
index f1680cf..e0e6c9f 100644
--- a/test/test_utils.dart
+++ b/test/test_utils.dart
@@ -343,12 +343,19 @@ void throwsIllegalArg(void Function() function, {String? reason}) {
   expect(function, throwsArgumentError, reason: reason);
 }
 
-void throwsArgParserException(ArgParser parser, List<String> args, String? arg,
-    {String? reason}) {
+void throwsFormat(ArgParser parser, List<String> args, {String? reason}) {
+  expect(() => parser.parse(args), throwsA(isA<FormatException>()),
+      reason: reason);
+}
+
+void throwsArgParserException(ArgParser parser, List<String> args,
+    String message, List<String> commands, String arg) {
   try {
     parser.parse(args);
     fail('Expected an ArgParserException');
   } on ArgParserException catch (e) {
+    expect(e.message, message);
+    expect(e.commands, commands);
     expect(e.arg, arg);
   } catch (e) {
     fail('Expected an ArgParserException, but got $e');
diff --git a/test/trailing_options_test.dart b/test/trailing_options_test.dart
index fb6bba0..db502d1 100644
--- a/test/trailing_options_test.dart
+++ b/test/trailing_options_test.dart
@@ -20,8 +20,7 @@ void main() {
     });
 
     void expectThrows(List<String> args, String arg) {
-      throwsArgParserException(parser, args, arg,
-          reason: 'with allowTrailingOptions: true');
+      throwsFormat(parser, args, reason: 'with allowTrailingOptions: true');
     }
 
     test('collects non-options in rest', () {

From b01f125a6a8abae3b6b21a0c12d39dc888c80ce3 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E3=81=B5=E3=81=81?=
 <34892635+fa0311@users.noreply.github.com>
Date: Thu, 26 Sep 2024 09:11:40 +0900
Subject: [PATCH 09/13] Update lib/src/arg_parser_exception.dart

Co-authored-by: Nate Bosch <nbosch1@gmail.com>
---
 lib/src/arg_parser_exception.dart | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/src/arg_parser_exception.dart b/lib/src/arg_parser_exception.dart
index dda5366..b1bdd25 100644
--- a/lib/src/arg_parser_exception.dart
+++ b/lib/src/arg_parser_exception.dart
@@ -9,7 +9,7 @@ class ArgParserException extends FormatException {
   /// This will be empty if the error was on the root parser.
   final List<String> commands;
 
-  /// The argument that were being parsed when the error was discovered.
+  /// The argument name that was being parsed when the error was discovered.
   final String? arg;
 
   ArgParserException(super.message,

From 290d75bb8edb5faa8b3e2708ca6611e149903720 Mon Sep 17 00:00:00 2001
From: Nate Bosch <nbosch@google.com>
Date: Mon, 30 Sep 2024 19:36:56 +0000
Subject: [PATCH 10/13] Change to feature version bump

Code using the new argument should depend on this version.
---
 CHANGELOG.md | 2 +-
 pubspec.yaml | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 26f4c5c..a205299 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,4 +1,4 @@
-## 2.5.1-wip
+## 2.6.0-wip
 
 * Added source argument when throwing a `ArgParserException`.
 * Fix inconsistent `FormatException` messages
diff --git a/pubspec.yaml b/pubspec.yaml
index 2b70992..8e59181 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -1,5 +1,5 @@
 name: args
-version: 2.5.1-wip
+version: 2.6.0-wip
 description: >-
   Library for defining parsers for parsing raw command-line arguments into a set
   of options and values using GNU and POSIX style options.

From 4e48231e4d2f032b7cd2cffc0eff79c631b1439b Mon Sep 17 00:00:00 2001
From: Nate Bosch <nbosch@google.com>
Date: Mon, 30 Sep 2024 19:50:35 +0000
Subject: [PATCH 11/13] Use a more specific name

Avoiding the acronym to follow Effective Dart, even though other names
still use the abbreviation.

Adding "Name" so the meaning is unambiguous.
---
 lib/src/arg_parser_exception.dart | 9 ++++++---
 lib/src/parser.dart               | 2 +-
 test/test_utils.dart              | 2 +-
 3 files changed, 8 insertions(+), 5 deletions(-)

diff --git a/lib/src/arg_parser_exception.dart b/lib/src/arg_parser_exception.dart
index b1bdd25..e6a1868 100644
--- a/lib/src/arg_parser_exception.dart
+++ b/lib/src/arg_parser_exception.dart
@@ -9,10 +9,13 @@ class ArgParserException extends FormatException {
   /// This will be empty if the error was on the root parser.
   final List<String> commands;
 
-  /// The argument name that was being parsed when the error was discovered.
-  final String? arg;
+  /// The name of the argument that was being parsed when the error was discovered.
+  final String? argumentName;
 
   ArgParserException(super.message,
-      [Iterable<String>? commands, this.arg, super.source, super.offset])
+      [Iterable<String>? commands,
+      this.argumentName,
+      super.source,
+      super.offset])
       : commands = commands == null ? const [] : List.unmodifiable(commands);
 }
diff --git a/lib/src/parser.dart b/lib/src/parser.dart
index 354ed2f..63ac111 100644
--- a/lib/src/parser.dart
+++ b/lib/src/parser.dart
@@ -74,7 +74,7 @@ class Parser {
           throw ArgParserException(
               error.message,
               [commandName, ...error.commands],
-              error.arg,
+              argumentNameerror.argumentName,
               error.source,
               error.offset);
         }
diff --git a/test/test_utils.dart b/test/test_utils.dart
index e0e6c9f..f7d8b8a 100644
--- a/test/test_utils.dart
+++ b/test/test_utils.dart
@@ -356,7 +356,7 @@ void throwsArgParserException(ArgParser parser, List<String> args,
   } on ArgParserException catch (e) {
     expect(e.message, message);
     expect(e.commands, commands);
-    expect(e.arg, arg);
+    expect(e.argumentName, arg);
   } catch (e) {
     fail('Expected an ArgParserException, but got $e');
   }

From 5ace87547f1b7d0744071029d1ddd4b3662b5987 Mon Sep 17 00:00:00 2001
From: Nate Bosch <nbosch@google.com>
Date: Mon, 30 Sep 2024 20:40:59 +0000
Subject: [PATCH 12/13] fix bad replace

---
 lib/src/parser.dart | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/src/parser.dart b/lib/src/parser.dart
index 63ac111..660e56d 100644
--- a/lib/src/parser.dart
+++ b/lib/src/parser.dart
@@ -74,7 +74,7 @@ class Parser {
           throw ArgParserException(
               error.message,
               [commandName, ...error.commands],
-              argumentNameerror.argumentName,
+              error.argumentName,
               error.source,
               error.offset);
         }

From 3b1b0bef1675b91717b44030b075f1dd87b7153f Mon Sep 17 00:00:00 2001
From: Nate Bosch <nbosch@google.com>
Date: Mon, 30 Sep 2024 20:43:21 +0000
Subject: [PATCH 13/13] Reflow comment

---
 lib/src/arg_parser_exception.dart | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/lib/src/arg_parser_exception.dart b/lib/src/arg_parser_exception.dart
index e6a1868..fbee82b 100644
--- a/lib/src/arg_parser_exception.dart
+++ b/lib/src/arg_parser_exception.dart
@@ -9,7 +9,8 @@ class ArgParserException extends FormatException {
   /// This will be empty if the error was on the root parser.
   final List<String> commands;
 
-  /// The name of the argument that was being parsed when the error was discovered.
+  /// The name of the argument that was being parsed when the error was
+  /// discovered.
   final String? argumentName;
 
   ArgParserException(super.message,