Support nested C# exceptions

* Inner exceptions
* Aggregate exceptions (from wait operations on failed tasks)
* Exceptions thrown from asynchronous code

Author: eadred

lib/fluent/plugin/exception_detector.rb

@@ -59,6 +59,23 @@ def self.supported
            :java_start_exception),
       rule(:java_after_exception, /^[\r\n]*$/, :java_after_exception),
       rule([:java_after_exception, :java], /^[\t ]+(?:eval )?at /, :java),
+
+      # C# nested exception
+      rule([:java_after_exception, :java],
+           /^[\t ]+--- End of inner exception stack trace ---/,
+           :java),
+
+      # C# aggregate exception
+      rule([:java_after_exception, :java],
+           /^---> \(Inner Exception #[0-9]+\)/,
+           :java),
+
+      # C# exception from async code
+      rule([:java_after_exception, :java],
+           %r{^---\sEnd\sof\sstack\strace\sfrom\sprevious\s
+           location\swhere\sexception\swas\sthrown\s---}x,
+           :java),
+
       rule([:java_after_exception, :java], /^[\t ]*(?:Caused by|Suppressed):/,
            :java_after_exception),
       rule([:java_after_exception, :java],

test/plugin/test_exception_detector.rb

@@ -256,6 +256,50 @@ class ExceptionDetectorTest < Test::Unit::TestCase
   at System.Threading.Thread.StartInternal () [0x00000] in <filename unknown>:0
 END
 
+  CSHARP_NESTED_EXC = <<END.freeze
+System.InvalidOperationException: This is the outer exception ---> System.InvalidOperationException: This is the inner exception
+  at ExampleApp.NestedExceptionExample.LowestLevelMethod() in c:/ExampleApp/ExampleApp/NestedExceptionExample.cs:line 33
+  at ExampleApp.NestedExceptionExample.ThirdLevelMethod() in c:/ExampleApp/ExampleApp/NestedExceptionExample.cs:line 28
+  at ExampleApp.NestedExceptionExample.SecondLevelMethod() in c:/ExampleApp/ExampleApp/NestedExceptionExample.cs:line 18
+  --- End of inner exception stack trace ---
+  at ExampleApp.NestedExceptionExample.SecondLevelMethod() in c:/ExampleApp/ExampleApp/NestedExceptionExample.cs:line 22
+  at ExampleApp.NestedExceptionExample.TopLevelMethod() in c:/ExampleApp/ExampleApp/NestedExceptionExample.cs:line 11
+  at ExampleApp.Program.Main(String[] args) in c:/ExampleApp/ExampleApp/Program.cs:line 11
+END
+
+  CSHARP_AGGREGATE_EXC = <<END.freeze
+System.AggregateException: One or more errors occurred. (This is an exception) ---> System.InvalidOperationException: This is an exception
+  at ExampleApp.AsyncExceptionExample.LowestLevelMethod() in c:/ExampleApp/ExampleApp/AsyncExceptionExample.cs:line 28
+  at ExampleApp.AsyncExceptionExample.ThirdLevelMethod() in c:/ExampleApp/ExampleApp/AsyncExceptionExample.cs:line 23
+  at ExampleApp.AsyncExceptionExample.SecondLevelMethod() in c:/ExampleApp/ExampleApp/AsyncExceptionExample.cs:line 17
+  at ExampleApp.AsyncExceptionExample.TopLevelMethod() in c:/ExampleApp/ExampleApp/AsyncExceptionExample.cs:line 12
+  --- End of inner exception stack trace ---
+  at System.Threading.Tasks.Task.Wait(Int32 millisecondsTimeout, CancellationToken cancellationToken)
+  at System.Threading.Tasks.Task.Wait()
+  at ExampleApp.Program.Main(String[] args) in c:/ExampleApp/ExampleApp/Program.cs:line 12
+---> (Inner Exception #0) System.InvalidOperationException: This is an exception
+  at ExampleApp.AsyncExceptionExample.LowestLevelMethod() in c:/ExampleApp/ExampleApp/AsyncExceptionExample.cs:line 28
+  at ExampleApp.AsyncExceptionExample.ThirdLevelMethod() in c:/ExampleApp/ExampleApp/AsyncExceptionExample.cs:line 23
+  at ExampleApp.AsyncExceptionExample.SecondLevelMethod() in c:/ExampleApp/ExampleApp/AsyncExceptionExample.cs:line 17
+  at ExampleApp.AsyncExceptionExample.TopLevelMethod() in c:/ExampleApp/ExampleApp/AsyncExceptionExample.cs:line 12<---
+END
+
+  CSHARP_ASYNC_EXC = <<END.freeze
+System.InvalidOperationException: This is an exception
+   at ExampleApp2.AsyncExceptionExample.LowestLevelMethod() in c:/ExampleApp/ExampleApp/AsyncExceptionExample.cs:line 36
+   at ExampleApp2.AsyncExceptionExample.<ThirdLevelMethod>d__2.MoveNext() in c:/ExampleApp/ExampleApp/AsyncExceptionExample.cs:line 31
+--- End of stack trace from previous location where exception was thrown ---
+   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
+   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
+   at System.Runtime.CompilerServices.TaskAwaiter.GetResult()
+   at ExampleApp2.AsyncExceptionExample.<SecondLevelMethod>d__1.MoveNext() in c:/ExampleApp/ExampleApp/AsyncExceptionExample.cs:line 25
+--- End of stack trace from previous location where exception was thrown ---
+   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
+   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
+   at System.Runtime.CompilerServices.TaskAwaiter.GetResult()
+   at ExampleApp2.AsyncExceptionExample.<TopLevelMethod>d__0.MoveNext() in c:/ExampleApp/ExampleApp/AsyncExceptionExample.cs:line 14
+END
+
   RUBY_EXC = <<END.freeze
  NoMethodError (undefined method `resursivewordload' for #<BooksController:0x007f8dd9a0c738>):
   app/controllers/books_controller.rb:69:in `recursivewordload'
@@ -570,6 +614,9 @@ def test_js
 
   def test_csharp
     check_exception(CSHARP_EXC, false)
+    check_exception(CSHARP_NESTED_EXC, false)
+    check_exception(CSHARP_AGGREGATE_EXC, false)
+    check_exception(CSHARP_ASYNC_EXC, false)
   end
 
   def test_python
@@ -627,6 +674,9 @@ def test_mixed_languages
     check_exception(GO_ON_GAE_EXC, false)
     check_exception(GO_SIGNAL_EXC, false)
     check_exception(CSHARP_EXC, false)
+    check_exception(CSHARP_NESTED_EXC, false)
+    check_exception(CSHARP_AGGREGATE_EXC, false)
+    check_exception(CSHARP_ASYNC_EXC, false)
     check_exception(V8_JS_EXC, false)
     check_exception(RUBY_EXC, false)
     check_exception(DART_ERR, false)