Make life a little more sparkly.

lib/src/log.dart

 // Copyright (c) 2012, 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.
 
 /// Message logging.
 import 'dart:async';
 import 'dart:convert';
 import 'dart:io';
 
 import 'package:args/command_runner.dart';
@@ skipping 11 matching lines @@
 ///
 ///     log.json.error(...);
 final json = new _JsonLogger();
 
 /// The current logging verbosity.
 Verbosity verbosity = Verbosity.NORMAL;
 
 /// Whether or not to log entries with prejudice.
 bool withPrejudice = false;
 
+/// Whether or not to log entries sparklily.
+bool sparkle = false;
+
 /// In cases where there's a ton of log spew, make sure we don't eat infinite
 /// memory.
 ///
 /// This can occur when the backtracking solver stumbles into a pathological
 /// dependency graph. It generally will find a solution, but it may log
 /// thousands and thousands of entries to get there.
 const _MAX_TRANSCRIPT = 10000;
 
 /// The list of recorded log messages. Will only be recorded if
 /// [recordTranscript()] is called.
 Transcript<Entry> _transcript;
 
 /// The currently-animated progress indicator, if any.
 ///
 /// This will also be in [_progresses].
 Progress _animatedProgress;
 
 _Collapser _collapser;
 
 final _cyan = getSpecial('\u001b[36m');
 final _green = getSpecial('\u001b[32m');
 final _magenta = getSpecial('\u001b[35m');
 final _red = getSpecial('\u001b[31m');
 final _yellow = getSpecial('\u001b[33m');
+final _blue = getSpecial('\u001b[34m');
 final _gray = getSpecial('\u001b[1;30m');
 final _none = getSpecial('\u001b[0m');
 final _noColor = getSpecial('\u001b[39m');
 final _bold = getSpecial('\u001b[1m');
 
+/// All color codees.
+var _allColors = [_cyan, _green, _magenta, _red, _yellow, _blue, ''];
+
 /// An enum type for defining the different logging levels a given message can
 /// be associated with.
 ///
 /// By default, [ERROR] and [WARNING] messages are printed to sterr. [MESSAGE]
 /// messages are printed to stdout, and others are ignored.
 class Level {
   /// An error occurred and an operation could not be completed.
   ///
   /// Usually shown to the user on stderr.
   static const ERROR = const Level._("ERR ");
@@ skipping 163 matching lines @@
   var entry = new Entry(level, lines.map(format).toList());
 
   var logFn = verbosity._loggers[level];
   if (logFn != null) logFn(entry);
 
   if (_transcript != null) _transcript.add(entry);
 }
 
 final _capitalizedAnsiEscape = new RegExp(r'\u001b\[\d+(;\d+)?M');
 
+final _character = new RegExp(r'(\u001b\[\d+(?:;\d+)?m)|.');
+
 /// Returns [string] formatted as it would be if it were logged.
 String format(String string) {
-  if (!withPrejudice) return string;
+  if (sparkle) {
+    string = string.replaceAllMapped(_character, (match) {
+      if (match[1] != null) return match[0];
+      var char = "${choose(_allColors)}${match[0]}$_noColor";
+      return (withPrejudice || random.nextBool()) ? char : "$_bold$char$_none";
+    });
+  }
 
-  // [toUpperCase] can corrupt terminal colorings, so fix them up using
-  // [replaceAllMapped].
-  string = string.toUpperCase().replaceAllMapped(_capitalizedAnsiEscape,
-      (match) => match[0].toLowerCase());
+  if (withPrejudice) {
+    // [toUpperCase] can corrupt terminal colorings, so fix them up using
+    // [replaceAllMapped].
+    string = string.toUpperCase().replaceAllMapped(_capitalizedAnsiEscape,
+        (match) => match[0].toLowerCase());
 
-  // Don't use [bold] because it's disabled under [withPrejudice].
-  return "$_bold$string$_none";
+    // Don't use [bold] because it's disabled under [withPrejudice].
+    string = "$_bold$string$_none";
+  }
+
+  return string;
 }
 
 /// Logs an asynchronous IO operation.
 ///
 /// Logs [startMessage] before the operation starts, then when [operation]
 /// completes, invokes [endMessage] with the completion value and logs the
 /// result of that. Returns a future that completes after the logging is done.
 ///
 /// If [endMessage] is omitted, then logs "Begin [startMessage]" before the
 /// operation and "End [startMessage]" after it.
@@ skipping 182 matching lines @@
   }
 }
 
 /// Wraps [text] in the ANSI escape codes to make it bold when on a platform
 /// that supports that.
 ///
 /// Use this to highlight the most important piece of a long chunk of text.
 ///
 /// This is disabled under [withPrejudice] since all text is bold with
 /// prejudice.
-String bold(text) => withPrejudice ? text : "$_bold$text$_none";
+String bold(text) => (withPrejudice || sparkle) ? text : "$_bold$text$_none";
 
 /// Wraps [text] in the ANSI escape codes to make it gray when on a platform
 /// that supports that.
 ///
 /// Use this for text that's less important than the text around it.
 ///
 /// The gray marker also enables bold, so it needs to be handled specially with
 /// [withPrejudice] to avoid disabling bolding entirely.
-String gray(text) =>
-    withPrejudice ? "$_gray$text$_noColor" : "$_gray$text$_none";
+String gray(text) {
+  if (sparkle) return text;
+  if (withPrejudice) return "$_gray$text$_noColor";
+  return "$_gray$text$_none";
+}
 
 /// Wraps [text] in the ANSI escape codes to color it cyan when on a platform
 /// that supports that.
 ///
 /// Use this to highlight something interesting but neither good nor bad.
-String cyan(text) => "$_cyan$text$_noColor";
+String cyan(text) => sparkle ? text : "$_cyan$text$_noColor";
 
 /// Wraps [text] in the ANSI escape codes to color it green when on a platform
 /// that supports that.
 ///
 /// Use this to highlight something successful or otherwise positive.
-String green(text) => "$_green$text$_noColor";
+String green(text) => sparkle ? text : "$_green$text$_noColor";
 
 /// Wraps [text] in the ANSI escape codes to color it magenta when on a
 /// platform that supports that.
 ///
 /// Use this to highlight something risky that the user should be aware of but
 /// may intend to do.
-String magenta(text) => "$_magenta$text$_noColor";
+String magenta(text) => sparkle ? text : "$_magenta$text$_noColor";
 
 /// Wraps [text] in the ANSI escape codes to color it red when on a platform
 /// that supports that.
 ///
 /// Use this to highlight unequivocal errors, problems, or failures.
-String red(text) => "$_red$text$_noColor";
+String red(text) => sparkle ? text : "$_red$text$_noColor";
 
 /// Wraps [text] in the ANSI escape codes to color it yellow when on a platform
 /// that supports that.
 ///
 /// Use this to highlight warnings, cautions or other things that are bad but
 /// do not prevent the user's goal from being reached.
-String yellow(text) => "$_yellow$text$_noColor";
+String yellow(text) => sparkle ? text : "$_yellow$text$_noColor";
 
 /// Log function that prints the message to stdout.
 void _logToStdout(Entry entry) {
   _logToStream(stdout, entry, showLabel: false);
 }
 
 /// Log function that prints the message to stdout with the level name.
 void _logToStdoutWithLabel(Entry entry) {
   _logToStream(stdout, entry, showLabel: true);
 }
@@ skipping 123 matching lines @@
       message(_firstMessage);
     } else {
       message(_template.replaceAll("##", _count.toString()));
     }
   }
 
   void _initTimer() {
     _timer = new Timer(_window, end);
   }
 }