Log errors happened in BackgroundWorker#perform (#1624)

* Log exceptions happened in background worker

* Provide a safer background worker method for monkey-patching

* Update changelog

CHANGELOG.md

@@ -5,6 +5,8 @@
 - Merge context with the same key instead of replacing the old value. [#1621](https://github.com/getsentry/sentry-ruby/pull/1621)
   - Fixes [#1619](https://github.com/getsentry/sentry-ruby/issues/1619)
 - Fix `HTTPTransport`'s `ssl` configuration [#1626](https://github.com/getsentry/sentry-ruby/pull/1626)
+- Log errors happened in `BackgroundWorker#perform` [#1624](https://github.com/getsentry/sentry-ruby/pull/1624)
+  - Fixes [#1618](https://github.com/getsentry/sentry-ruby/issues/1618)
 
 ### Refactoring
 

sentry-rails/lib/sentry/rails/background_worker.rb

@@ -1,11 +1,9 @@
 module Sentry
   class BackgroundWorker
-    def perform(&block)
-      @executor.post do
-        # make sure the background worker returns AR connection if it accidentally acquire one during serialization
-        ActiveRecord::Base.connection_pool.with_connection do
-          block.call
-        end
+    def _perform(&block)
+      # make sure the background worker returns AR connection if it accidentally acquire one during serialization
+      ActiveRecord::Base.connection_pool.with_connection do
+        block.call
       end
     end
   end

sentry-ruby/lib/sentry/background_worker.rb

@@ -12,6 +12,7 @@ def initialize(configuration)
       @max_queue = 30
       @number_of_threads = configuration.background_worker_threads
       @logger = configuration.logger
+      @debug = configuration.debug
 
       @executor =
         if configuration.async
@@ -32,10 +33,21 @@ def initialize(configuration)
         end
     end
 
+    # if you want to monkey-patch this method, please override `_perform` instead
     def perform(&block)
       @executor.post do
-        block.call
+        begin
+          _perform(&block)
+        rescue Exception => e
+          log_error("exception happened in background worker", e, debug: @debug)
+        end
       end
     end
+
+    private
+
+    def _perform(&block)
+      block.call
+    end
   end
 end

sentry-ruby/spec/sentry/background_worker_spec.rb

@@ -3,13 +3,13 @@
 RSpec.describe Sentry::BackgroundWorker do
   let(:string_io) { StringIO.new }
 
-  describe "#initialize" do
-    let(:configuration) do
-      Sentry::Configuration.new.tap do |config|
-        config.logger = Logger.new(string_io)
-      end
+  let(:configuration) do
+    Sentry::Configuration.new.tap do |config|
+      config.logger = Logger.new(string_io)
     end
+  end
 
+  describe "#initialize" do
     context "when config.async is set" do
       before do
         configuration.async = proc {}
@@ -67,4 +67,19 @@
       end
     end
   end
+
+  describe "#perform" do
+    before { configuration.background_worker_threads = 1 }
+
+    it "logs error message when failed" do
+      worker = described_class.new(configuration)
+
+      worker.perform do
+        1/0
+      end
+
+      sleep(0.1)
+      expect(string_io.string).to match(/exception happened in background worker: divided by 0/)
+    end
+  end
 end