Add a boolean which causes AnalysisServer to rethrow exceptions.

pkg/analysis_server/lib/src/analysis_server.dart

Index: pkg/analysis_server/lib/src/analysis_server.dart
diff --git a/pkg/analysis_server/lib/src/analysis_server.dart b/pkg/analysis_server/lib/src/analysis_server.dart
index 80cc62451c9a2d77e01ce8c54f0118b3ab94299c..016fe802b30a605b8f9d44ff2441d7937be3b587 100644
--- a/pkg/analysis_server/lib/src/analysis_server.dart
+++ b/pkg/analysis_server/lib/src/analysis_server.dart
@@ -22,6 +22,7 @@ import 'package:analyzer/src/generated/sdk.dart';
 import 'package:analyzer/src/generated/sdk_io.dart';
 import 'package:analyzer/src/generated/source_io.dart';
 import 'package:analysis_server/src/computers.dart';
+import 'package:analyzer/src/generated/java_engine.dart';
 
 
 /**
@@ -126,10 +127,22 @@ class AnalysisServer {
   Map<AnalysisService, Set<String>> analysisServices = <AnalysisService, Set<String>>{};
 
   /**
+   * True if any exceptions thrown by analysis should be propagated up the call
+   * stack.
+   */
+  bool rethrowExceptions;
+
+  /**
    * Initialize a newly created server to receive requests from and send
    * responses to the given [channel].
+   *
+   * If [rethrowExceptions] is true, then any exceptions thrown by analysis are
+   * propagated up the call stack.  The default is true to allow analysis
+   * exceptions to show up in unit tests, but it should be set to false when
+   * running a full analysis server.
    */
-  AnalysisServer(this.channel, ResourceProvider resourceProvider) {
+  AnalysisServer(this.channel, ResourceProvider resourceProvider,
+      {this.rethrowExceptions: true}) {
     contextDirectoryManager = new AnalysisServerContextDirectoryManager(this, resourceProvider);
     AnalysisEngine.instance.logger = new AnalysisLogger();
     running = true;
@@ -225,6 +238,13 @@ class AnalysisServer {
       sendStatusNotification(context.toString());
       AnalysisResult result = context.performAnalysisTask();
       notices = result.changeNotices;
+    } catch (exception, stackTrace) {
+      AnalysisEngine.instance.logger.logError("${exception}\n${stackTrace}");
+      if (rethrowExceptions) {
+        throw new AnalysisException(
+            'Unexpected exception during analysis',
+            new CaughtException(exception, stackTrace));
+      }
     } finally {
       if (notices == null) {
         // Either we have no more work to do for this context, or there was an
@@ -451,9 +471,7 @@ class AnalysisServer {
   }
 
   void _scheduleTask() {
-    new Future(performTask).catchError((ex, st) {
-      AnalysisEngine.instance.logger.logError("${ex}\n${st}");
-    });
+    new Future(performTask);
   }
 }