add error and stack trace info to BuilderTransformer logs

Author: jakemac53

CHANGELOG.md

@@ -1,5 +1,8 @@
 # Changelog
 
+## 0.3.0+4
+- Add error and stack trace to log nessages from the BuilderTransformer.
+
 ## 0.3.0+3
 - Fixed BuilderTransformer so that logs are passed on to the TransformLogger.
 

lib/src/transformer/transformer.dart

@@ -76,13 +76,13 @@ abstract class BuilderTransformer implements Transformer, DeclaringTransformer {
       Logger.root.level = Level.ALL;
       var logSubscription = buildStep.logger.onRecord.listen((LogRecord log) {
         if (log.level <= Level.CONFIG) {
-          transform.logger.fine(log.message);
+          transform.logger.fine(_logRecordToMessage(log));
         } else if (log.level <= Level.INFO) {
-          transform.logger.info(log.message);
+          transform.logger.info(_logRecordToMessage(log));
         } else if (log.level <= Level.WARNING) {
-          transform.logger.warning(log.message);
+          transform.logger.warning(_logRecordToMessage(log));
         } else {
-          transform.logger.error(log.message);
+          transform.logger.error(_logRecordToMessage(log));
         }
       });
       await builder.build(buildStep);
@@ -91,6 +91,18 @@ abstract class BuilderTransformer implements Transformer, DeclaringTransformer {
     }));
   }
 
+  String _logRecordToMessage(LogRecord log) {
+    var buffer = new StringBuffer();
+    buffer.write(log.message);
+    if (log.error != null) {
+      buffer.write('\nError: ${log.error}');
+    }
+    if (log.stackTrace != null) {
+      buffer.write('\nStack Trace:\n${log.stackTrace}');
+    }
+    return buffer.toString();
+  }
+
   @override
   void declareOutputs(DeclaringTransform transform) {
     for (var outputId in _expectedOutputs(transform.primaryId, builders)) {

pubspec.yaml

@@ -1,5 +1,5 @@
 name: build
-version: 0.3.0+3
+version: 0.3.0+4
 description: A build system for Dart.
 author: Dart Team <[email protected]>
 homepage: https://github.com/dart-lang/build

test/transformer/transformer_test.dart

@@ -123,8 +123,10 @@ void main() {
   ], {
     'a|web/a.txt': 'hello',
   }, {}, messages: [
-    'warning: Warning!',
-    'error: Error!',
+    allOf(startsWith('warning: Warning!'), contains('SomeError'),
+        contains('LoggingCopyBuilder.build')),
+    allOf(startsWith('error: Error!'), contains('SomeError'),
+        contains('LoggingCopyBuilder.build')),
   ]);
 }
 
@@ -134,8 +136,12 @@ class LoggingCopyBuilder extends CopyBuilder {
   @override
   Future build(BuildStep buildStep) async {
     await super.build(buildStep);
-    buildStep.logger.warning('Warning!');
-    buildStep.logger.severe('Error!');
+    try {
+      throw 'SomeError';
+    } catch (e, s) {
+      buildStep.logger.warning('Warning!', e, s);
+      buildStep.logger.severe('Error!', e, s);
+    }
   }
 }