False positive for package_names lint for Pub Workspace name

[n-bernat]

When creating a pub workspace with analysis_options.yaml in the root directory, it reports that the package name of the main pubspec.yaml is invalid when it's set to name: _.

• Dart: 3.7.2

Directory structure:

• /pubspec.yaml
• /analysis_options.yaml
• /package_a
• /package_b
• /package_c

Contents of /pubspec.yaml:

name: _
publish_to: none
environment:
  sdk: ^3.6.0

workspace:
  - package_a
  - package_b
  - package_c

If I understand correctly the following regular expression fails:

sdk/pkg/linter/lib/src/utils.dart

Lines 39 to 46 in 4f3a672

	// A lower-case underscored (snake-case) with leading underscores is defined as
	// * An optional leading sequence of any number of underscores,
	// * followed by a sequence of lower-case letters, digits and underscores,
	// * with no two adjacent underscores,
	// * and not ending in an underscore.
	final _lowerCaseUnderScoreWithLeadingUnderscores = RegExp(
	r'^_*[a-z](?:_?[a-z\d])*$',
	);

Which is the first check in:

sdk/pkg/linter/lib/src/utils.dart

Lines 94 to 98 in 4f3a672

	/// Returns true if this [id] is a valid package name.
	bool isValidPackageName(String id) =>
	_lowerCaseUnderScoreWithLeadingUnderscores.hasMatch(id) &&
	isIdentifier(id) &&
	!isReservedWord(id);

[bwilkerson]

@jonasfj