Use ansi color in the dartanalyzer cli output.

pkg/analyzer_cli/lib/src/error_formatter.dart

Index: pkg/analyzer_cli/lib/src/error_formatter.dart
diff --git a/pkg/analyzer_cli/lib/src/error_formatter.dart b/pkg/analyzer_cli/lib/src/error_formatter.dart
index 722fbd2da540f2b0b4611dcb5d641a6fe9425ef4..bac7f7ce80ad1137acd8a1517ac13209d41eeb88 100644
--- a/pkg/analyzer_cli/lib/src/error_formatter.dart
+++ b/pkg/analyzer_cli/lib/src/error_formatter.dart
@@ -7,6 +7,7 @@ library analyzer_cli.src.error_formatter;
 import 'package:analyzer/error/error.dart';
 import 'package:analyzer/src/generated/engine.dart';
 import 'package:analyzer/src/generated/source.dart';
+import 'package:analyzer_cli/src/ansi.dart';
 import 'package:analyzer_cli/src/options.dart';
 import 'package:path/path.dart' as path;
 
@@ -103,6 +104,7 @@ class AnalysisStats {
 }
 
 /// Helper for formatting [AnalysisError]s.
+///
 /// The two format options are a user consumable format and a machine consumable
 /// format.
 class ErrorFormatter {
@@ -117,8 +119,12 @@ class ErrorFormatter {
 
   final _SeverityProcessor processSeverity;
 
+  AnsiLogger ansi;
+
   ErrorFormatter(this.out, this.options, this.stats,
-      [this.processSeverity = _identity]);
+      [this.processSeverity = _identity]) {
+    ansi = new AnsiLogger(this.options.color);
+  }
 
   /// Compute the severity for this [error] or `null` if this error should be
   /// filtered.
@@ -168,15 +174,21 @@ class ErrorFormatter {
         }
       }
 
-      int indent = errorType.length + 3;
+      final int errLength = ErrorSeverity.WARNING.displayName.length;
+      final int indent = errLength + 5;
 
-      // [warning] 'foo' is not a bar at lib/foo.dart:1:2 (foo_warning).
+      // warning • 'foo' is not a bar at lib/foo.dart:1:2 • foo_warning
       String message = error.message;
       // Remove any terminating '.' from the end of the message.
       if (message.endsWith('.')) {
         message = message.substring(0, message.length - 1);
       }
-      out.write('[$errorType] $message ');
+      String issueColor =
+          (severity == ErrorSeverity.ERROR || severity == ErrorSeverity.WARNING)
+              ? ansi.red
+              : '';
+      out.write('  $issueColor${errorType.padLeft(errLength)}${ansi.none} '
+          '${ansi.bullet} ${ansi.bold}$message${ansi.none} ');
       String sourceName;
       if (source.uriKind == UriKind.DART_URI) {
         sourceName = source.uri.toString();
@@ -191,7 +203,7 @@ class ErrorFormatter {
       }
       out.write('at $sourceName');
       out.write(':${location.lineNumber}:${location.columnNumber} ');
-      out.write('(${error.errorCode.name.toLowerCase()}).');
+      out.write('${ansi.bullet} ${error.errorCode.name.toLowerCase()}');
       out.writeln();
 
       // If verbose, also print any associated correction.