Adopt Shopify's Ruby style guide (rubocop-shopify)

.github/workflows/ci.yml

@@ -7,6 +7,16 @@ on:
     branches: [main, master]
 
 jobs:
+  lint:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: ruby/setup-ruby@v1
+        with:
+          ruby-version: '4.0'
+          bundler-cache: true
+      - run: bundle exec rubocop
+
   test:
     runs-on: ubuntu-latest
     strategy:

.rubocop.yml

@@ -0,0 +1,5 @@
+inherit_gem:
+  rubocop-shopify: rubocop.yml
+
+AllCops:
+  SuggestExtensions: false

Gemfile

@@ -1,6 +1,12 @@
+# frozen_string_literal: true
+
 source "https://rubygems.org"
 
-git_source(:github) {|repo_name| "https://github.com/#{repo_name}" }
+git_source(:github) { |repo_name| "https://github.com/#{repo_name}" }
 
 # Specify your gem's dependencies in ast_transform.gemspec
 gemspec
+
+# Transitive dependency of rubocop: parallel >= 2 requires Ruby >= 3.3, but we
+# still support 3.2. Drop this pin when our Ruby floor moves to 3.3.
+gem "parallel", "< 2", require: false

Gemfile.lock

@@ -16,13 +16,17 @@ GEM
     diff-lcs (1.6.2)
     docile (1.4.1)
     io-console (0.8.2)
+    json (2.21.1)
+    language_server-protocol (3.17.0.6)
+    lint_roller (1.1.0)
     method_source (1.1.0)
     minitest (5.27.0)
     minitest-reporters (1.7.1)
       ansi
       builder
       minitest (>= 5.0)
       ruby-progressbar
+    parallel (1.28.0)
     parser (3.3.10.2)
       ast (~> 2.4.1)
       racc
@@ -32,16 +36,37 @@ GEM
       method_source (~> 1.0)
       reline (>= 0.6.0)
     racc (1.8.1)
+    rainbow (3.1.1)
     rake (13.3.1)
+    regexp_parser (2.12.0)
     reline (0.6.3)
       io-console (~> 0.5)
+    rubocop (1.88.2)
+      json (~> 2.3)
+      language_server-protocol (~> 3.17.0.2)
+      lint_roller (~> 1.1.0)
+      parallel (>= 1.10)
+      parser (>= 3.3.0.2)
+      rainbow (>= 2.2.2, < 4.0)
+      regexp_parser (>= 2.9.3, < 3.0)
+      rubocop-ast (>= 1.49.0, < 2.0)
+      ruby-progressbar (~> 1.7)
+      unicode-display_width (>= 2.4.0, < 4.0)
+    rubocop-ast (1.50.0)
+      parser (>= 3.3.7.2)
+      prism (~> 1.7)
+    rubocop-shopify (2.18.0)
+      rubocop (~> 1.62)
     ruby-progressbar (1.13.0)
     simplecov (0.22.0)
       docile (~> 1.1)
       simplecov-html (~> 0.11)
       simplecov_json_formatter (~> 0.1)
     simplecov-html (0.13.2)
     simplecov_json_formatter (0.1.4)
+    unicode-display_width (3.2.0)
+      unicode-emoji (~> 4.1)
+    unicode-emoji (4.2.0)
     unparser (0.8.1)
       diff-lcs (~> 1.6)
       parser (>= 3.3.0)
@@ -56,8 +81,10 @@ DEPENDENCIES
   bundler (>= 2.1)
   minitest (~> 5.14)
   minitest-reporters (~> 1.4)
+  parallel (< 2)
   pry (>= 0.14)
   rake (~> 13.0)
+  rubocop-shopify (~> 2.18)
   simplecov (~> 0.22)
 
 BUNDLED WITH

Rakefile

@@ -1,16 +1,17 @@
 # frozen_string_literal: true
-require 'bundler/gem_tasks'
-require 'rake/testtask'
+
+require "bundler/gem_tasks"
+require "rake/testtask"
 
 Rake::TestTask.new(:test) do |t|
   # Ensure we load test_loader first for ASTTransform.install
-  filepath = File.expand_path('test/test_loader.rb', __dir__)
+  filepath = File.expand_path("test/test_loader.rb", __dir__)
   t.ruby_opts << "-r #{filepath}"
   t.warning = false
 
-  t.libs << 'test'
-  t.libs << 'lib'
-  t.test_files = FileList['test/**/*_test.rb']
+  t.libs << "test"
+  t.libs << "lib"
+  t.test_files = FileList["test/**/*_test.rb"]
 end
 
-task :default => :test
+task default: :test

ast_transform.gemspec

@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 
 lib = File.expand_path("../lib", __FILE__)
 $LOAD_PATH.unshift(lib) unless $LOAD_PATH.include?(lib)
@@ -9,28 +10,30 @@ Gem::Specification.new do |spec|
   spec.authors       = ["Jean-Philippe Duchesne"]
   spec.email         = ["jpduchesne89@gmail.com"]
 
-  spec.summary       = 'An AST transformation framework.'
+  spec.summary       = "An AST transformation framework."
   spec.description   = spec.summary
   spec.homepage      = "https://github.com/rspockframework/ast-transform"
   spec.license       = "MIT"
-  spec.files         = `git ls-files -z`.split("\x0").reject do |f|
+  spec.files         = %x(git ls-files -z).split("\x0").reject do |f|
     f.match(%r{^(test|spec|features)/})
   end
   spec.bindir        = "exe"
   spec.executables   = spec.files.grep(%r{^exe/}) { |f| File.basename(f) }
   spec.require_paths = ["lib"]
-  spec.required_ruby_version = '>= 3.2'
+  spec.required_ruby_version = ">= 3.2"
 
   # Development dependencies
-  spec.add_development_dependency "bundler", ">= 2.1"
-  spec.add_development_dependency "rake", "~> 13.0"
-  spec.add_development_dependency "minitest", "~> 5.14"
-  spec.add_development_dependency "minitest-reporters", "~> 1.4"
-  spec.add_development_dependency "pry", ">= 0.14"
-  spec.add_development_dependency "simplecov", "~> 0.22"
+  spec.add_development_dependency("bundler", ">= 2.1")
+  spec.add_development_dependency("minitest", "~> 5.14")
+  spec.add_development_dependency("minitest-reporters", "~> 1.4")
+  spec.add_development_dependency("pry", ">= 0.14")
+  spec.add_development_dependency("rake", "~> 13.0")
+  # rubocop-shopify >= 3.0 requires Ruby >= 3.3; bump alongside our own floor.
+  spec.add_development_dependency("rubocop-shopify", "~> 2.18")
+  spec.add_development_dependency("simplecov", "~> 0.22")
 
   # Runtime dependencies
-  spec.add_runtime_dependency "parser", ">= 3.0"
-  spec.add_runtime_dependency "prism", ">= 1.5"
-  spec.add_runtime_dependency "unparser", ">= 0.6"
+  spec.add_runtime_dependency("parser", ">= 3.0")
+  spec.add_runtime_dependency("prism", ">= 1.5")
+  spec.add_runtime_dependency("unparser", ">= 0.6")
 end

bin/console

@@ -1,4 +1,5 @@
 #!/usr/bin/env ruby
+# frozen_string_literal: true
 
 require "bundler/setup"
 require "ast_transform"

dev.yml

@@ -0,0 +1,11 @@
+name: ast_transform
+commands:
+  up:
+    desc: Install gems
+    run: bundle install
+  test:
+    desc: Run this repo's tests
+    run: bundle exec rake test
+  style:
+    desc: Run RuboCop
+    run: bundle exec rubocop

lib/ast_transform.rb

@@ -1,9 +1,9 @@
 # frozen_string_literal: true
 
 require "ast_transform/version"
-require 'ast_transform/instruction_sequence'
-require 'ast_transform/instruction_sequence/mixin'
-require 'ast_transform/instruction_sequence/bootsnap_mixin'
+require "ast_transform/instruction_sequence"
+require "ast_transform/instruction_sequence/mixin"
+require "ast_transform/instruction_sequence/bootsnap_mixin"
 
 module ASTTransform
   DEFAULT_OUTPUT_PATH = Pathname.new("").join("tmp", "ast_transform").to_s
@@ -19,22 +19,18 @@ def acronym(acronym)
     end
 
     def install
-      @installed ||= begin
-        if defined?(Bootsnap) && ASTTransform::InstructionSequence.using_bootsnap_compilation?
-          class << Bootsnap::CompileCache::ISeq
-            prepend ::ASTTransform::InstructionSequence::BootsnapMixin
-          end
-        else
-          class << RubyVM::InstructionSequence
-            prepend ::ASTTransform::InstructionSequence::Mixin
-          end
+      @installed ||= if defined?(Bootsnap) && ASTTransform::InstructionSequence.using_bootsnap_compilation?
+        class << Bootsnap::CompileCache::ISeq
+          prepend ::ASTTransform::InstructionSequence::BootsnapMixin
+        end
+      else
+        class << RubyVM::InstructionSequence
+          prepend ::ASTTransform::InstructionSequence::Mixin
         end
       end
     end
 
-    def output_path=(path)
-      @output_path = path
-    end
+    attr_writer :output_path
 
     def output_path
       @output_path || DEFAULT_OUTPUT_PATH

lib/ast_transform/abstract_transformation.rb

@@ -1,5 +1,6 @@
 # frozen_string_literal: true
-require 'ast_transform/transformation_helper'
+
+require "ast_transform/transformation_helper"
 
 module ASTTransform
   class AbstractTransformation < Parser::AST::Processor

lib/ast_transform/instruction_sequence.rb

@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 module ASTTransform
   module InstructionSequence
     class << self
@@ -22,12 +23,12 @@ def source_to_transformed_iseq(source, source_path)
       def write_pathname(file_path)
         project_path = File.expand_path("")
         relative_source_file_pathname = Pathname.new(file_path).relative_path_from(Pathname.new(project_path))
-        Pathname.new("").join(project_path, 'tmp', 'ast_transform', relative_source_file_pathname)
+        Pathname.new("").join(project_path, "tmp", "ast_transform", relative_source_file_pathname)
       end
 
       def write(string, pathname)
         FileUtils.mkdir_p(pathname.dirname)
-        File.open(pathname, 'w') do |file|
+        File.open(pathname, "w") do |file|
           file.write(string)
         end
       end

lib/ast_transform/instruction_sequence/bootsnap_mixin.rb

@@ -1,8 +1,8 @@
 # frozen_string_literal: true
 
-require 'ast_transform/transformer'
-require 'ast_transform/instruction_sequence/mixin_utils'
-require 'pathname'
+require "ast_transform/transformer"
+require "ast_transform/instruction_sequence/mixin_utils"
+require "pathname"
 
 module ASTTransform
   module InstructionSequence
@@ -14,7 +14,7 @@ def input_to_storage(source, source_path)
         iseq = ASTTransform::InstructionSequence.source_to_transformed_iseq(source, source_path)
         iseq.to_binary
       rescue SyntaxError
-        raise ::Bootsnap::CompileCache::Uncompilable, 'syntax error'
+        raise ::Bootsnap::CompileCache::Uncompilable, "syntax error"
       end
     end
   end

lib/ast_transform/instruction_sequence/mixin.rb

@@ -1,8 +1,9 @@
 # frozen_string_literal: true
-require 'pathname'
-require 'ast_transform/transformer'
-require 'ast_transform/transformation'
-require 'ast_transform/instruction_sequence/mixin_utils'
+
+require "pathname"
+require "ast_transform/transformer"
+require "ast_transform/transformation"
+require "ast_transform/instruction_sequence/mixin_utils"
 
 module ASTTransform
   module InstructionSequence
@@ -15,7 +16,7 @@ def load_iseq(source_path)
         # via magic comments, so we never need to set it ourselves.
         source = File.binread(source_path)
 
-        return ASTTransform::MixinUtils.try_super(self, :load_iseq, source_path) unless source.include?('transform!'.b)
+        return ASTTransform::MixinUtils.try_super(self, :load_iseq, source_path) unless source.include?("transform!".b)
 
         ASTTransform::InstructionSequence.source_to_transformed_iseq(source, source_path)
       end

lib/ast_transform/instruction_sequence/mixin_utils.rb

@@ -5,7 +5,7 @@ module MixinUtils
     class << self
       def try_super(target, method_sym, *args, &block)
         super_method = target.method(method_sym).super_method
-        super_method ? super_method.call(*args, &block) : nil
+        super_method&.call(*args, &block)
       end
     end
   end

lib/ast_transform/kwargs_builder.rb

@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require 'prism/translation/parser'
+require "prism/translation/parser"
 
 module ASTTransform
   # Extends the default Prism parser builder to distinguish keyword arguments

lib/ast_transform/source_map.rb

@@ -1,5 +1,6 @@
 # frozen_string_literal: true
-require 'parser'
+
+require "parser"
 
 module ASTTransform
   class SourceMap
@@ -28,7 +29,9 @@ def for_file_path(file_path)
       private
 
       def source_maps
-        @@source_maps ||= {}
+        # Class instance var (not @@): read/written only through this method
+        # inside class << self, and SourceMap has no subclasses to share with.
+        @source_maps ||= {}
       end
     end
 
@@ -97,7 +100,7 @@ def extract_source_map_data(node, indexes)
     #
     # @return [Hash] A Hash containing line numbers from executed code to source code.
     def build_source_map
-      (1..line_count).each.with_object({}) {|it, hash| hash[it] = source_line(it) }
+      (1..line_count).each.with_object({}) { |it, hash| hash[it] = source_line(it) }
     end
 
     # Retrieves the source line for the given +line_number+ in the executed code.
@@ -226,6 +229,7 @@ def dig_last_valid_node(node, indexes)
     def dig_node(node, indexes)
       indexes.inject(node) do |node, index|
         return nil unless node.is_a?(Parser::AST::Node)
+
         node.children[index]
       end
     end