Log thread name for gem development debugging (#1085)

spec/test_app/config/application.rb

@@ -1,10 +1,11 @@
 require_relative 'boot'
 
 require 'rails/all'
+require "good_job"
 require "good_job/engine"
 
 Bundler.require(*Rails.groups)
-require "good_job"
+require_relative "../lib/thread_name_formatter"
 
 module TestApp
   class Application < Rails::Application
@@ -16,6 +17,7 @@ class Application < Rails::Application
     # -- all .rb files in that directory are automatically loaded after loading
     # the framework and any gems in your application.
     #
+    config.log_formatter = ThreadNameFormatter.new
 
     config.active_job.queue_adapter = :good_job
 

spec/test_app/lib/thread_name_formatter.rb

@@ -0,0 +1,32 @@
+# frozen_string_literal: true
+class ThreadNameFormatter < ActiveSupport::Logger::SimpleFormatter
+  def call(severity, timestamp, _progname, message)
+    prefix = [emoji_hash(Thread.current.name), Thread.current.name, emoji_hash(Thread.current.name)].compact.join(" ")
+    "#{ActiveSupport::LogSubscriber.new.send(:color, "[#{prefix}]", :magenta)} #{super}"
+  end
+
+  def emoji_hash(str)
+    # Hash the input string using SHA256
+    digest = Digest::SHA256.hexdigest(str || "")
+
+    # Take the first few characters from the hash
+    partial_digest = digest[0..4].to_i(16)
+
+    # Define the ranges for the emojis
+    ranges = [
+      (0x1F345..0x1F35E), # Vegetables and some other food items
+      (0x1F400..0x1F43E) # Animals
+    ]
+
+    # Combine all ranges into a single array of code points
+    all_emojis = ranges.flat_map { |r| r.to_a }
+
+    # Compute an index within the all_emojis array
+    index = partial_digest % all_emojis.length
+
+    # Convert the code point to a character (emoji)
+    emoji = [all_emojis[index]].pack('U*')
+
+    emoji
+  end
+end