Opt into Ruby frozen string literals throughout the codebase (#446)

This PR adds the `# frozen_string_literal: true` comment to all of
tomo's Ruby files.

This prepares tomo for a future version of Ruby (4?), where string
literals will likely become frozen by default.

.rubocop.yml

@@ -111,9 +111,6 @@ Style/FetchEnvVar:
 Style/FormatStringToken:
   Enabled: false
 
-Style/FrozenStringLiteralComment:
-  Enabled: false
-
 Style/NumericLiterals:
   Enabled: false
 

Gemfile

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 source "https://rubygems.org"
 gemspec
 

Rakefile

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "bundler/gem_tasks"
 require "rake/testtask"
 require "rubocop/rake_task"

exe/tomo

@@ -1,4 +1,5 @@
 #!/usr/bin/env ruby
+# frozen_string_literal: true
 
 require "tomo"
 Tomo::CLI.new.call(ARGV)

lib/tomo.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Tomo
   autoload :CLI, "tomo/cli"
   autoload :Colors, "tomo/colors"
@@ -21,7 +23,7 @@ module Tomo
   autoload :TaskLibrary, "tomo/task_library"
   autoload :VERSION, "tomo/version"
 
-  DEFAULT_CONFIG_PATH = ".tomo/config.rb".freeze
+  DEFAULT_CONFIG_PATH = ".tomo/config.rb"
 
   class << self
     attr_accessor :logger

lib/tomo/cli.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Tomo
   class CLI
     autoload :Command, "tomo/cli/command"

lib/tomo/cli/command.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Tomo
   class CLI
     class Command

lib/tomo/cli/common_options.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Tomo
   class CLI
     module CommonOptions

lib/tomo/cli/completions.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Tomo
   class CLI
     class Completions

lib/tomo/cli/deploy_options.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Tomo
   class CLI
     module DeployOptions

lib/tomo/cli/error.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Tomo
   class CLI
     class Error < ::Tomo::Error

lib/tomo/cli/interrupted_error.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Tomo
   class CLI
     class InterruptedError < Error

lib/tomo/cli/options.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Tomo
   class CLI
     class Options

lib/tomo/cli/parser.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "forwardable"
 
 module Tomo

lib/tomo/cli/project_options.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Tomo
   class CLI
     module ProjectOptions

lib/tomo/cli/rules.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Tomo
   class CLI
     class Rules

lib/tomo/cli/rules/argument.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Tomo::CLI::Rules
   class Argument
     def initialize(label, values_proc:, multiple: false, required: false)

lib/tomo/cli/rules/switch.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Tomo::CLI::Rules
   class Switch
     def initialize(key, *switches, callback_proc:, required: false, &convert_proc)

lib/tomo/cli/rules/value_switch.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Tomo::CLI::Rules
   class ValueSwitch < Switch
     include Tomo::Colors

lib/tomo/cli/rules_evaluator.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Tomo
   class CLI
     class RulesEvaluator

lib/tomo/cli/state.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Tomo
   class CLI
     class State

lib/tomo/cli/usage.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Tomo
   class CLI
     class Usage

lib/tomo/colors.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Tomo
   module Colors
     ANSI_CODES = {

lib/tomo/commands.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Tomo
   module Commands
     autoload :CompletionScript, "tomo/commands/completion_script"

lib/tomo/commands/completion_script.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Tomo
   module Commands
     class CompletionScript

lib/tomo/commands/default.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Tomo
   module Commands
     class Default < CLI::Command

lib/tomo/commands/deploy.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Tomo
   module Commands
     class Deploy < CLI::Command

lib/tomo/commands/help.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Tomo
   module Commands
     class Help

lib/tomo/commands/init.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "erb"
 require "fileutils"
 

lib/tomo/commands/run.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Tomo
   module Commands
     class Run < CLI::Command

lib/tomo/commands/setup.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Tomo
   module Commands
     class Setup < CLI::Command

lib/tomo/commands/tasks.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Tomo
   module Commands
     class Tasks < CLI::Command

lib/tomo/commands/version.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Tomo
   module Commands
     class Version < CLI::Command

lib/tomo/configuration.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Tomo
   class Configuration
     autoload :DSL, "tomo/configuration/dsl"

lib/tomo/configuration/dsl.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Tomo
   class Configuration
     module DSL

lib/tomo/configuration/dsl/batch_block.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Tomo
   class Configuration
     module DSL

lib/tomo/configuration/dsl/config_file.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Tomo
   class Configuration
     module DSL

lib/tomo/configuration/dsl/environment_block.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Tomo
   class Configuration
     module DSL

lib/tomo/configuration/dsl/error_formatter.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Tomo
   class Configuration
     module DSL
@@ -55,7 +57,7 @@ def highlighted_lines # rubocop:disable Metrics/AbcSize
           last = [dsl_lines.length, error_line_no + 1].min
           width = last.to_s.length
 
-          (first..last).each_with_object("") do |line_no, result|
+          (first..last).each_with_object(+"") do |line_no, result|
             line = dsl_lines[line_no - 1]
             line_no_prefix = line_no.to_s.rjust(width)
 

lib/tomo/configuration/dsl/hosts_and_settings.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Tomo
   class Configuration
     module DSL

lib/tomo/configuration/dsl/tasks_block.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Tomo
   class Configuration
     module DSL

lib/tomo/configuration/environment.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Tomo
   class Configuration
     class Environment

lib/tomo/configuration/glob.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Tomo
   class Configuration
     class Glob

lib/tomo/configuration/plugin_file_not_found_error.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Tomo
   class Configuration
     class PluginFileNotFoundError < Error

lib/tomo/configuration/plugins_registry.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Tomo
   class Configuration
     class PluginsRegistry

lib/tomo/configuration/plugins_registry/file_resolver.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Tomo
   class Configuration
     class PluginsRegistry::FileResolver

lib/tomo/configuration/plugins_registry/gem_resolver.rb

@@ -1,7 +1,9 @@
+# frozen_string_literal: true
+
 module Tomo
   class Configuration
     class PluginsRegistry::GemResolver
-      PLUGIN_PREFIX = "tomo/plugin".freeze
+      PLUGIN_PREFIX = "tomo/plugin"
       private_constant :PLUGIN_PREFIX
 
       def self.resolve(name)

lib/tomo/configuration/project_not_found_error.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Tomo
   class Configuration
     class ProjectNotFoundError < Tomo::Error

lib/tomo/configuration/role_based_task_filter.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Tomo
   class Configuration
     class RoleBasedTaskFilter

lib/tomo/configuration/unknown_environment_error.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Tomo
   class Configuration
     class UnknownEnvironmentError < Tomo::Error
@@ -23,10 +25,10 @@ def wrong_envs
         ERROR
 
         if suggestions.any?
-          error << suggestions.to_console
+          error + suggestions.to_console
         else
           envs = known_environments.map { |env| blue("  #{env}") }
-          error << <<~ENVS
+          error + <<~ENVS
 
             The following environments are available:
 

lib/tomo/configuration/unknown_plugin_error.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Tomo
   class Configuration
     class UnknownPluginError < Tomo::Error
@@ -9,9 +11,9 @@ def to_console
         ERROR
 
         sugg = Error::Suggestions.new(dictionary: known_plugins, word: name)
-        error << sugg.to_console if sugg.any?
+        error += sugg.to_console if sugg.any?
 
-        error << gem_suggestion
+        error + gem_suggestion
       end
 
       private

lib/tomo/configuration/unspecified_environment_error.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Tomo
   class Configuration
     class UnspecifiedEnvironmentError < Tomo::Error

lib/tomo/console.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "forwardable"
 require "io/console"
 

lib/tomo/console/key_reader.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "forwardable"
 require "io/console"
 require "time"
@@ -35,7 +37,7 @@ def seconds_since_last_press
       end
 
       def read_chars_nonblock
-        chars = ""
+        chars = +""
         loop do
           next_char = raw { read_nonblock(1) }
           break if next_char.nil?