Prefer require_relative for internal requires

`require_relative` is preferred over `require` for files within the same
project because it uses paths relative to the current file, making code
more portable and less dependent on the load path.

This change updates internal requires to use `require_relative` for
consistency, performance, and improved portability.

Refs:
- rubocop/rubocop#8748

lib/shakapacker.rb

@@ -37,13 +37,13 @@ def ensure_log_goes_to_stdout
   delegate :bootstrap, :clean, :clobber, :compile, to: :commands
 end
 
-require "shakapacker/instance"
-require "shakapacker/env"
-require "shakapacker/configuration"
-require "shakapacker/manifest"
-require "shakapacker/compiler"
-require "shakapacker/commands"
-require "shakapacker/dev_server"
-require "shakapacker/deprecation_helper"
-
-require "shakapacker/railtie" if defined?(Rails)
+require_relative "shakapacker/instance"
+require_relative "shakapacker/env"
+require_relative "shakapacker/configuration"
+require_relative "shakapacker/manifest"
+require_relative "shakapacker/compiler"
+require_relative "shakapacker/commands"
+require_relative "shakapacker/dev_server"
+require_relative "shakapacker/deprecation_helper"
+
+require_relative "shakapacker/railtie" if defined?(Rails)

lib/shakapacker/compiler.rb

@@ -1,7 +1,8 @@
 require "open3"
-require "shakapacker/compiler_strategy"
 require "fileutils"
 
+require_relative "compiler_strategy"
+
 class Shakapacker::Compiler
   # Additional environment variables that the compiler is being run with
   # Shakapacker::Compiler.env['FRONTEND_API_KEY'] = 'your_secret_key'

lib/shakapacker/compiler_strategy.rb

@@ -1,5 +1,5 @@
-require "shakapacker/mtime_strategy"
-require "shakapacker/digest_strategy"
+require_relative "mtime_strategy"
+require_relative "digest_strategy"
 
 module Shakapacker
   class CompilerStrategy

lib/shakapacker/dev_server_runner.rb

@@ -1,8 +1,9 @@
 require "shellwords"
 require "socket"
-require "shakapacker/configuration"
-require "shakapacker/dev_server"
-require "shakapacker/runner"
+
+require_relative "configuration"
+require_relative "dev_server"
+require_relative "runner"
 
 module Shakapacker
   class DevServerRunner < Shakapacker::Runner

lib/shakapacker/digest_strategy.rb

@@ -1,5 +1,6 @@
 require "digest/sha1"
-require "shakapacker/base_strategy"
+
+require_relative "base_strategy"
 
 module Shakapacker
   class DigestStrategy < BaseStrategy

lib/shakapacker/mtime_strategy.rb

@@ -1,4 +1,4 @@
-require "shakapacker/base_strategy"
+require_relative "base_strategy"
 
 module Shakapacker
   class MtimeStrategy < BaseStrategy

lib/shakapacker/railtie.rb

@@ -1,9 +1,9 @@
 require "rails/railtie"
 
-require "shakapacker/helper"
-require "shakapacker/dev_server_proxy"
-require "shakapacker/version_checker"
-require "shakapacker/utils/manager"
+require_relative "helper"
+require_relative "dev_server_proxy"
+require_relative "version_checker"
+require_relative "utils/manager"
 
 class Shakapacker::Engine < ::Rails::Engine
   # Allows Shakapacker config values to be set via Rails env config files

lib/shakapacker/runner.rb

@@ -1,5 +1,6 @@
-require "shakapacker/utils/misc"
-require "shakapacker/utils/manager"
+require_relative "utils/misc"
+require_relative "utils/manager"
+
 require "package_json"
 
 module Shakapacker

lib/shakapacker/version_checker.rb

@@ -1,5 +1,5 @@
 # frozen_string_literal: true
-require "shakapacker/version"
+require_relative "version"
 
 module Shakapacker
   class VersionChecker

lib/shakapacker/webpack_runner.rb

@@ -1,5 +1,6 @@
 require "shellwords"
-require "shakapacker/runner"
+
+require_relative "runner"
 
 module Shakapacker
   class WebpackRunner < Shakapacker::Runner