Add tests for Gitlab::ErrorTracking::LogFormatter

Issue https://gitlab.com/gitlab-com/gl-infra/scalability/-/issues/846

lib/gitlab/error_tracking/context_payload_generator.rb

@@ -61,6 +61,9 @@ module Gitlab
       end
 
       def current_context
+        # In case Gitlab::ErrorTracking is used when the app starts
+        return {} unless defined?(::Gitlab::ApplicationContext)
+
         ::Gitlab::ApplicationContext.current.to_h
       end
     end

lib/gitlab/error_tracking/log_formatter.rb

@@ -3,6 +3,9 @@
 module Gitlab
   module ErrorTracking
     class LogFormatter
+      # Note: all the accesses to Raven's contexts here are to keep the
+      # backward-compatibility to Sentry's built-in integrations. In future,
+      # they can be removed.
       def self.format!(payload, exception, context_payload)
         Gitlab::ExceptionLogFormatter.format!(exception, payload)
         append_user_to_log!(payload, context_payload)
@@ -29,6 +32,7 @@ module Gitlab
         extra = extra.except(:server)
 
         sidekiq_extra = extra[:sidekiq]
+        # The extra value for sidekiq is a hash whose keys are strings.
         if sidekiq_extra.is_a?(Hash) && sidekiq_extra.key?('args')
           sidekiq_extra = sidekiq_extra.dup
           sidekiq_extra['args'] = Gitlab::ErrorTracking::Processor::SidekiqProcessor.loggable_arguments(

spec/lib/gitlab/error_tracking/log_formatter_spec.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe Gitlab::ErrorTracking::LogFormatter do
+  let(:exception) { StandardError.new('boom') }
+  let(:context_payload) do
+    {
+      user: {
+        ip_address: '127.0.0.1',
+        username: 'root'
+      },
+      tags: {
+        locale: 'en',
+        feature_category: 'category_a'
+      },
+      extra: {
+        some_other_info: 'other_info',
+        sidekiq: {
+          'class' => 'HelloWorker',
+          'args' => ['senstive string', 1, 2],
+          'another_field' => 'field'
+        }
+      }
+    }
+  end
+
+  before do
+    Raven.context.user[:user_flag] = 'flag'
+    Raven.context.tags[:shard] = 'catchall'
+    Raven.context.extra[:some_info] = 'info'
+
+    allow(exception).to receive(:backtrace).and_return(
+      [
+        'lib/gitlab/file_a.rb:1',
+        'lib/gitlab/file_b.rb:2'
+      ]
+    )
+  end
+
+  after do
+    ::Raven::Context.clear!
+  end
+
+  it 'appends error-related log fields' do
+    payload = {}
+
+    described_class.format!(payload, exception, context_payload)
+
+    expect(payload).to eql(
+      'exception.class' => 'StandardError',
+      'exception.message' => 'boom',
+      'exception.backtrace' => [
+        'lib/gitlab/file_a.rb:1',
+        'lib/gitlab/file_b.rb:2'
+      ],
+      'user.ip_address' => '127.0.0.1',
+      'user.username' => 'root',
+      'user.user_flag' => 'flag',
+      'tags.locale' => 'en',
+      'tags.feature_category' => 'category_a',
+      'tags.shard' => 'catchall',
+      'extra.some_other_info' => 'other_info',
+      'extra.some_info' => 'info',
+      "extra.sidekiq" => {
+        "another_field" => "field",
+        "args" => ["[FILTERED]", "1", "2"],
+        "class" => "HelloWorker"
+      }
+    )
+  end
+end