pkg/analysis_server/test/stress/utilities/logger.dart

// Copyright (c) 2017, the Dart project authors. Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.

/// A utility class used to write logging information during a test.
class Logger {
  /// The width of the field in which labels are printed.
  static const int _labelWidth = 8;

  /// The separator used to separate the label from the content.
  static const String _separator = ' : ';

  /// The sink to which the logged information should be written.
  final StringSink sink;

  /// Initialize a newly created logger to write to the given [sink].
  Logger(this.sink);

  /// Log the given information.
  ///
  /// The [label] is used to indicate the kind of information being logged,
  /// while the [content] contains the actual information. If a list of
  /// [arguments] is provided, then they will be written after the content.
  void log(String label, String content, {List<String> arguments}) {
    for (var i = _labelWidth - label.length; i > 0; i--) {
      sink.write(' ');
    }
    sink.write(label);
    sink.write(_separator);
    sink.write(content);
    arguments?.forEach((String argument) {
      sink.write(' ');
      sink.write(argument);
    });
    sink.writeln();
  }
}