DDC: mostly incremental compilation, fixes #223

lib/src/report.dart

Index: lib/src/report.dart
diff --git a/lib/src/report.dart b/lib/src/report.dart
index 6c74fe1ee2c435217d4c3273bac07f1a8ecb2238..3f164c0f263187c02b9f866f44055441f62467fd 100644
--- a/lib/src/report.dart
+++ b/lib/src/report.dart
@@ -6,6 +6,7 @@
 library dev_compiler.src.report;
 
 import 'dart:math' show max;
+import 'dart:io';
 
 import 'package:analyzer/src/generated/engine.dart' show AnalysisContext;
 import 'package:analyzer/src/generated/error.dart';
@@ -20,13 +21,18 @@ final _checkerLogger = new Logger('dev_compiler.checker');
 
 /// Collects errors, and then sorts them and sends them
 class ErrorCollector implements AnalysisErrorListener {
+  final AnalysisContext context;
   final AnalysisErrorListener listener;
   final List<AnalysisError> _errors = [];
+  final bool saveMessages;
+  final Level logLevel;
 
-  ErrorCollector(this.listener);
+  ErrorCollector(this.context, AnalysisErrorListener listener, this.logLevel,
+      {this.saveMessages: false})
+      : listener = listener ?? AnalysisErrorListener.NULL_LISTENER;
 
   /// Flushes errors to the log. Until this is called, errors are buffered.
-  void flush() {
+  void flush(String messagePath) {
     // TODO(jmesserly): this code was taken from analyzer_cli.
     // sort errors
     _errors.sort((AnalysisError error1, AnalysisError error2) {
@@ -49,7 +55,27 @@ class ErrorCollector implements AnalysisErrorListener {
       return error1.message.compareTo(error2.message);
     });
 
-    _errors.forEach(listener.onError);
+    if (saveMessages && messagePath != null) {
+      var text = new StringBuffer();
+      for (var e in _errors) {
+        // TODO(jmesserly): don't use log level for this.
+        var level = _severityToLevel[_strongModeErrorSeverity(e)];
+        if (level >= logLevel) {
+          text
+            ..write(level.name.toLowerCase())
+            ..write(': ')
+            ..writeln(_messageToString(context, e));
+        }
+      }
+      var messageFile = new File(messagePath);
+      if (text.isNotEmpty) {
+        messageFile.writeAsStringSync(text.toString());
+      } else if (messageFile.existsSync()) {
+        messageFile.deleteSync();
+      }
+    } else {
+      _errors.forEach(listener.onError);
+    }
     _errors.clear();
   }
 
@@ -72,28 +98,29 @@ ErrorSeverity _strongModeErrorSeverity(AnalysisError error) {
 /// Simple reporter that logs checker messages as they are seen.
 class LogReporter implements AnalysisErrorListener {
   final AnalysisContext _context;
-  final bool useColors;
-  final List<AnalysisError> _errors = [];
 
-  LogReporter(this._context, {this.useColors: false});
+  LogReporter(this._context);
 
   void onError(AnalysisError error) {
     var level = _severityToLevel[_strongModeErrorSeverity(error)];
+    // TODO(jmesserly): just print these instead of sending through logger?
+    _checkerLogger.log(level, _messageToString(_context, error));
+  }
+}
 
-    // TODO(jmesserly): figure out what to do with the error's name.
-    var lineInfo = _context.computeLineInfo(error.source);
-    var location = lineInfo.getLocation(error.offset);
+String _messageToString(AnalysisContext context, AnalysisError error) {
+  // TODO(jmesserly): figure out what to do with the error's name.
+  var lineInfo = context.computeLineInfo(error.source);
+  var location = lineInfo.getLocation(error.offset);
 
-    // [warning] 'foo' is not a... (/Users/.../tmp/foo.dart, line 1, col 2)
-    var text = new StringBuffer()
-      ..write('[${errorCodeName(error.errorCode)}] ')
-      ..write(error.message)
-      ..write(' (${path.prettyUri(error.source.uri)}')
-      ..write(', line ${location.lineNumber}, col ${location.columnNumber})');
+  // [warning] 'foo' is not a... (/Users/.../tmp/foo.dart, line 1, col 2)
+  var text = new StringBuffer()
+    ..write('[${errorCodeName(error.errorCode)}] ')
+    ..write(error.message)
+    ..write(' (${path.prettyUri(error.source.uri)}')
+    ..write(', line ${location.lineNumber}, col ${location.columnNumber})');
 
-    // TODO(jmesserly): just print these instead of sending through logger?
-    _checkerLogger.log(level, text);
-  }
+  return text.toString();
 }
 
 // TODO(jmesserly): remove log levels, instead just use severity.