Dynamic log level based on http status of request

.gitignore

@@ -1,5 +1,6 @@
 *.gem
 .bundle
+.idea
 Gemfile.lock
 gemfiles/*.lock
 pkg/*

.rubocop.yml

@@ -11,5 +11,8 @@ AllCops:
 Metrics/AbcSize:
   Enabled: false
 
+Metrics/ClassLength:
+  Enabled: false
+
 Style/EmptyMethod:
   Enabled: false

lib/lograge.rb

@@ -87,6 +87,10 @@ def ignore?(event)
   mattr_accessor :log_level
   self.log_level = :info
 
+  # Log level may be calculated based on http status by setting map_log_level = true
+  mattr_accessor :map_log_level
+  self.map_log_level = false
+
   # The emitted log format
   #
   # Currently supported formats are>
@@ -171,6 +175,7 @@ def set_lograge_log_options
     Lograge.custom_options = lograge_config.custom_options
     Lograge.before_format = lograge_config.before_format
     Lograge.log_level = lograge_config.log_level || :info
+    Lograge.map_log_level = lograge_config.map_log_level
   end
 
   def disable_rack_cache_verbose_output

lib/lograge/log_subscriber.rb

@@ -12,8 +12,9 @@ def process_action(event)
       payload = event.payload
       data = extract_request(event, payload)
       data = before_format(data, payload)
+      log_level = Lograge.map_log_level ? log_level_for_status(payload) : Lograge.log_level
       formatted_message = Lograge.formatter.call(data)
-      logger.send(Lograge.log_level, formatted_message)
+      logger.send(log_level, formatted_message)
     end
 
     def redirect_to(event)
@@ -70,6 +71,19 @@ def extract_format(payload)
       end
     end
 
+    def log_level_for_status(payload)
+      status = extract_status(payload)[:status]
+      if status < 300
+        :info
+      elsif status < 400
+        :warn
+      elsif status < 500
+        :error
+      else
+        :fatal
+      end
+    end
+
     def extract_status(payload)
       if (status = payload[:status])
         { status: status.to_i }

lib/lograge/version.rb

@@ -1,3 +1,3 @@
 module Lograge
-  VERSION = '0.10.0'.freeze
+  VERSION = '0.11.0'.freeze
 end

spec/lograge_logsubscriber_spec.rb

@@ -32,8 +32,60 @@
     )
   end
 
+  let(:event_with_error) do
+    ActiveSupport::Notifications::Event.new(
+      'process_action.action_controller',
+      Time.now,
+      Time.now,
+      2,
+      status: 400,
+      controller: 'HomeController',
+      action: 'index',
+      format: 'application/json',
+      method: 'GET',
+      path: '/home?foo=bar',
+      params: event_params,
+      db_runtime: 0.02,
+      view_runtime: 0.01
+    )
+  end
+
   before { Lograge.logger = logger }
 
+  context 'log_level' do
+    context 'with map_log_level = false (default)' do
+      it 'outputs ok response as INFO' do
+        expect(logger).to receive(:info)
+        expect(logger).to_not receive(:error)
+        subscriber.process_action(event)
+      end
+
+      it 'outputs error response as INFO' do
+        expect(logger).to receive(:info)
+        expect(logger).to_not receive(:error)
+        subscriber.process_action(event_with_error)
+      end
+    end
+
+    context 'with map_log_level = true' do
+      before do
+        Lograge.map_log_level = true
+      end
+
+      it 'outputs ok response as INFO' do
+        expect(logger).to receive(:info)
+        expect(logger).to_not receive(:error)
+        subscriber.process_action(event)
+      end
+
+      it 'outputs error response as ERROR' do
+        expect(logger).to_not receive(:info)
+        expect(logger).to receive(:error)
+        subscriber.process_action(event_with_error)
+      end
+    end
+  end
+
   context 'with custom_options configured for cee output' do
     before do
       Lograge.formatter = ->(data) { "My test: #{data}" }