kddnewton

• CRuby
• Cardinal
• IronRuby
• JRuby
• MacRuby
• MagLev
• RIL
• Sorbet
• TruffleRuby
• lib-ruby-parser

kddnewton

#!/usr/bin/env ruby

# The purpose of this script is to extract all constant references from a given
# source file. It reads ARGF, which means you can either pass the content in
# through stdin or you can pass the file name as an argument. So for example,
# you can either:
#
#     echo 'Foo::Bar' | ./constants
#
# or you can pass a file name, as in:

kddnewton

# This class is responsible for publishing a post. This is basically a curried
# global function that is addressable through the PublishPost class. It can be
# easily tested, since its only dependency is the post that it accepts.
class PublishPost
  attr_reader :post

  def initialize(post)
    @post = post
  end

kddnewton

require "minitest/autorun"

class TemplatingTest < Minitest::Test
  def test_positional_argument_splats
    assert_templates <<~RUBY, "h1", "*args"
      @_target << "<h1>" << _output(*args) << "</h1>"
    RUBY
  end

  def test_multiple_positional_argument_splats

kddnewton

# This module is a light implementation of pattern matching that allows us to
# match against hashes and arrays as we would with the new pattern matching
# syntax.
module Pattern
  class ArrayPattern
    attr_reader :values

    def initialize(values)
      @values = values
    end

kddnewton

# Imagine we need to switch on some kind of input and do something based on some
# attribute of that input. We can do this with a case statement, where we inline
# each of the implementations of the interface that we're defining into the case
# statement. That would look something like:

class Input
  attr_reader :type, :name

  def initialize(type, name)
    @type = type

kddnewton

#!/usr/bin/env ruby
# frozen_string_literal: true

require "bundler/inline"

gemfile do
  source "https://rubygems.org"
  gem "syntax_tree"
end

kddnewton

require "syntax_tree"

# Create a new visitor that is going to visit the parsed tree.
visitor = SyntaxTree::Visitor::MutationVisitor.new

# Define a mutation on the visitor that is going to search for the given pattern
# to find nodes that match it and then call the given block to mutate the node
# in place in the tree.
visitor.mutate("If[predicate: Assign | OpAssign]") do |node|
  # Get the existing If's predicate node.

kddnewton

# frozen_string_literal: true

module SyntaxTree
  # This class is used to create a mutation that transforms syntax trees based
  # on various linting rules.
  class Linter
    def mutation
      SyntaxTree.mutation do |mutator|
        # Lint/AssignmentInCondition
        mutator.mutate("IfNode[predicate: Assign | OpAssign] | UnlessNode[predicate: Assign | OpAssign] | WhileNode[predicate: Assign | OpAssign] | UntilNode[predicate: Assign | OpAssign]") do |node|

kddnewton

def count(iseq)
  iseq[12].select { _1 in [:ensure | :rescue, *] }.sum { count(_1[1]) } +
  iseq[13].sum do
    case _1
    in Integer | Symbol
      0
    in [*, ["YARVInstructionSequence/SimpleDataFormat", *] => child, *]
      1 + count(child)
    in Array
      1