Add default_attributes to Logger

This adds the ability to add default attributes to a logger object. One usecase for this: You create a Logger, for which you already know a specific attribute, you can now set it on the initialize instead of having to pass it around all the time.
appsignal · Nov 12, 2024 · 27e05af · 27e05af
1 parent 8b234ca
commit 27e05af
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Showing 3 changed files with 20 additions and 3 deletions.
diff --git a/.changesets/add-default-attributes-to-logger.md b/.changesets/add-default-attributes-to-logger.md
@@ -0,0 +1,6 @@
+---
+bump: patch
+type: add
+---
+
+Add default attributes to Logger
diff --git a/lib/appsignal/logger.rb b/lib/appsignal/logger.rb
@@ -20,20 +20,21 @@ class Logger < ::Logger
       FATAL => 7
     }.freeze
 
-    attr_reader :level
+    attr_reader :level, :default_attributes
 
     # Create a new logger instance
     #
     # @param group Name of the group for this logger.
     # @param level Log level to filter with
     # @return [void]
-    def initialize(group, level: INFO, format: PLAINTEXT)
+    def initialize(group, level: INFO, format: PLAINTEXT, default_attributes: {})
       raise TypeError, "group must be a string" unless group.is_a? String
 
       @group = group
       @level = level
       @format = format
       @mutex = Mutex.new
+      @default_attributes = default_attributes
     end
 
     # We support the various methods in the Ruby
@@ -157,7 +158,7 @@ def silence(_severity = ERROR, &block)
     private
 
     def add_with_attributes(severity, message, group, attributes)
-      Thread.current[:appsignal_logger_attributes] = attributes
+      Thread.current[:appsignal_logger_attributes] = default_attributes.merge!(attributes)
       add(severity, message, group)
     ensure
       Thread.current[:appsignal_logger_attributes] = nil

diff --git a/spec/lib/appsignal/logger_spec.rb b/spec/lib/appsignal/logger_spec.rb
@@ -182,6 +182,16 @@
     end
   end
 
+  describe "a logger with default attributes" do
+    it "adds the attributes when a message is logged" do
+      logger = Appsignal::Logger.new("group", :default_attributes => { :some_key => "some_value" })
+
+      expect(Appsignal::Extension).to receive(:log).with("group", 6, 0, "Some message",
+        Appsignal::Utils::Data.generate({ :other_key => "other_value", :some_key => "some_value" }))
+      logger.error("Some message", { :other_key => "other_value" })
+    end
+  end
+
   describe "#error with exception object" do
     it "logs the exception class and its message" do
       error =