Allow multiple start states for a rule. Support nested Java exceptions. Handle Java logback. (#52)

Author: igorpeshansky

.rubocop.yml

@@ -14,6 +14,11 @@ Metrics/AbcSize:
 Metrics/ClassLength:
   Max: 1300
 
+# Offense count: 1
+# Configuration parameters: CountComments.
+Metrics/ModuleLength:
+  Max: 150
+
 # Offense count: 3
 Metrics/CyclomaticComplexity:
   Max: 50

lib/fluent/plugin/exception_detector.rb

@@ -13,7 +13,7 @@
 # limitations under the License.
 #
 module Fluent
-  Struct.new('Rule', :from_state, :pattern, :to_state)
+  Struct.new('Rule', :from_states, :pattern, :to_state)
 
   # Configuration of the state machine that detects exceptions.
   module ExceptionDetectorConfig
@@ -41,21 +41,28 @@ def state
       end
     end
 
-    def self.rule(from_state, pattern, to_state)
-      Struct::Rule.new(from_state, pattern, to_state)
+    def self.rule(from_state_or_states, pattern, to_state)
+      from_state_or_states = [from_state_or_states] unless
+        from_state_or_states.is_a?(Array)
+      Struct::Rule.new(from_state_or_states, pattern, to_state)
     end
 
     def self.supported
       RULES_BY_LANG.keys
     end
 
     JAVA_RULES = [
-      rule(:start_state,
+      rule([:start_state, :java_start_exception],
            /(?:Exception|Error|Throwable|V8 errors stack trace)[:\r\n]/,
-           :java),
-      rule(:java, /^[\t ]+(?:eval )?at /, :java),
-      rule(:java, /^[\t ]*(?:Caused by|Suppressed):/, :java),
-      rule(:java, /^[\t ]*... \d+\ more/, :java)
+           :java_after_exception),
+      rule(:java_after_exception, /^[\t ]*nested exception is:[\t ]*/,
+           :java_start_exception),
+      rule(:java_after_exception, /^[\r\n]*$/, :java_after_exception),
+      rule([:java_after_exception, :java], /^[\t ]+(?:eval )?at /, :java),
+      rule([:java_after_exception, :java], /^[\t ]*(?:Caused by|Suppressed):/,
+           :java_after_exception),
+      rule([:java_after_exception, :java],
+           /^[\t ]*... \d+ (?:more|common frames omitted)/, :java)
     ].freeze
 
     PYTHON_RULES = [
@@ -76,13 +83,12 @@ def self.supported
 
     GO_RULES = [
       rule(:start_state, /\bpanic: /, :go_after_panic),
-      rule(:go_after_panic, /^$/, :go_goroutine),
+      rule([:go_after_panic, :go_after_signal, :go_frame_1],
+           /^$/, :go_goroutine),
       rule(:go_after_panic, /^\[signal /, :go_after_signal),
-      rule(:go_after_signal, /^$/, :go_goroutine),
       rule(:go_goroutine, /^goroutine \d+ \[[^\]]+\]:$/, :go_frame_1),
       rule(:go_frame_1, /^(?:[^\s.:]+\.)*[^\s.():]+\(|^created by /,
            :go_frame_2),
-      rule(:go_frame_1, /^$/, :go_goroutine),
       rule(:go_frame_2, /^\s/, :go_frame_1)
     ].freeze
 
@@ -169,7 +175,9 @@ def initialize(*languages)
         rule_config.each do |r|
           target = ExceptionDetectorConfig::RuleTarget.new(r[:pattern],
                                                            r[:to_state])
-          @rules[r[:from_state]] << target
+          r[:from_states].each do |from_state|
+            @rules[from_state] << target
+          end
         end
       end
 

test/plugin/test_exception_detector.rb

@@ -59,7 +59,35 @@ class ExceptionDetectorTest < Test::Unit::TestCase
     at org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java:511)
     at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1166)
     at com.example.myproject.OpenSessionInViewFilter.doFilter(OpenSessionInViewFilter.java:30)
-    ... 27 more
+    ... 27 common frames omitted
+END
+
+  NESTED_JAVA_EXC = <<END.freeze
+java.lang.RuntimeException: javax.mail.SendFailedException: Invalid Addresses;
+  nested exception is:
+com.sun.mail.smtp.SMTPAddressFailedException: 550 5.7.1 <[REDACTED_EMAIL_ADDRESS]>... Relaying denied
+
+	at com.nethunt.crm.api.server.adminsync.AutomaticEmailFacade.sendWithSmtp(AutomaticEmailFacade.java:236)
+	at com.nethunt.crm.api.server.adminsync.AutomaticEmailFacade.sendSingleEmail(AutomaticEmailFacade.java:285)
+	at com.nethunt.crm.api.server.adminsync.AutomaticEmailFacade.lambda$sendSingleEmail$3(AutomaticEmailFacade.java:254)
+	at java.util.Optional.ifPresent(Optional.java:159)
+	at com.nethunt.crm.api.server.adminsync.AutomaticEmailFacade.sendSingleEmail(AutomaticEmailFacade.java:253)
+	at com.nethunt.crm.api.server.adminsync.AutomaticEmailFacade.sendSingleEmail(AutomaticEmailFacade.java:249)
+	at com.nethunt.crm.api.email.EmailSender.lambda$notifyPerson$0(EmailSender.java:80)
+	at com.nethunt.crm.api.util.ManagedExecutor.lambda$execute$0(ManagedExecutor.java:36)
+	at com.nethunt.crm.api.util.RequestContextActivator.lambda$withRequestContext$0(RequestContextActivator.java:36)
+	at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
+	at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
+	at java.base/java.lang.Thread.run(Thread.java:748)
+Caused by: javax.mail.SendFailedException: Invalid Addresses;
+  nested exception is:
+com.sun.mail.smtp.SMTPAddressFailedException: 550 5.7.1 <[REDACTED_EMAIL_ADDRESS]>... Relaying denied
+
+	at com.sun.mail.smtp.SMTPTransport.rcptTo(SMTPTransport.java:2064)
+	at com.sun.mail.smtp.SMTPTransport.sendMessage(SMTPTransport.java:1286)
+	at com.nethunt.crm.api.server.adminsync.AutomaticEmailFacade.sendWithSmtp(AutomaticEmailFacade.java:229)
+	... 12 more
+Caused by: com.sun.mail.smtp.SMTPAddressFailedException: 550 5.7.1 <[REDACTED_EMAIL_ADDRESS]>... Relaying denied
 END
 
   NODE_JS_EXC = <<END.freeze
@@ -531,6 +559,7 @@ def check_exception(exception, detects_end)
   def test_java
     check_exception(JAVA_EXC, false)
     check_exception(COMPLEX_JAVA_EXC, false)
+    check_exception(NESTED_JAVA_EXC, false)
   end
 
   def test_js