Class: RuboCop::Cop::Require::MissingRequireStatement

Inherits:
RuboCop::Cop
  • Object
show all
Defined in:
lib/rubocop/cop/require/missing_require_statement.rb

Overview

Checks for missing require statements in your code

Examples:

# bad
Faraday.new

# good
require 'faraday'

Faraday.new

Constant Summary collapse

MSG = 
'`%<constant>s` not found, you\'re probably missing a require statement or there is a cycle in your dependencies.'.freeze

Instance Attribute Summary collapse

Instance Method Summary collapse

Instance Attribute Details

#timeline ⇒ Object 



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# File 'lib/rubocop/cop/require/missing_require_statement.rb', line 24

def timeline
  @timeline ||= []
end

Instance Method Details

#add_offense(node, location: nil, message:) ⇒ Object 



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# File 'lib/rubocop/cop/require/missing_require_statement.rb', line 66

def add_offense(node, location: nil, message:)
  # Work around breaking API changes between rubocop 0.49.1 and later (...)
  signature_old = %i[node loc message severity]
  param_info = RuboCop::Cop::Cop.instance_method(:add_offense).parameters
  if param_info.map(&:last) == signature_old
    super(node, location || :expression, message)
  elsif location
    super(node, location: location, message: message)
  else
    super(node, message: message)
  end
end

#find_consts(node) ⇒ Object 



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# File 'lib/rubocop/cop/require/missing_require_statement.rb', line 87

def find_consts(node)
  inner = node
  outer_const = extract_const(node)
  return unless outer_const
  consts = [outer_const]
  while (inner = extract_inner_const(inner))
    const = extract_const(inner)
    consts << const
  end
  consts.reverse
end

#investigate(processed_source) ⇒ Object

Builds



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# File 'lib/rubocop/cop/require/missing_require_statement.rb', line 29

def investigate(processed_source)
  processing_methods = self.methods.select { |m| m.to_s.start_with? 'process_' }

  stack = [processed_source.ast]
  skip = Set.new
  until stack.empty?
    node = stack.pop
    next unless node

    results = processing_methods.map { |m| self.send(m, node, processed_source) }.compact

    next if node.kind_of? Hash

    to_skip, to_push = %i[skip push].map { |mode| results.flat_map { |r| r[mode] }.compact }

    skip.merge(to_skip)

    children_to_explore = node.children
                              .select { |c| c.kind_of? RuboCop::AST::Node }
                              .reject { |c| skip.include? c }
                              .reverse
    stack.push(*to_push)
    stack.push(*children_to_explore)
  end

  err_events = check_timeline(timeline).group_by { |e| e[:name] }.values
  err_events.each do |events|
    first = events.first
    node = first[:node]
    message = format(
      MSG,
      constant: first[:name]
    )
    add_offense(node, message: message)
  end
end

#process_const(node, _source) ⇒ Object 



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# File 'lib/rubocop/cop/require/missing_require_statement.rb', line 99

def process_const(node, _source)
  return unless node.kind_of? RuboCop::AST::Node
  consts = find_consts(node)
  return unless consts
  const_name = consts.join('::')

  self.timeline << { event: :const_access, name: const_name, node: node }

  { skip: node.children }
end

#process_const_assign(node, _source) ⇒ Object 



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# File 'lib/rubocop/cop/require/missing_require_statement.rb', line 114

def process_const_assign(node, _source)
  return unless node.kind_of? RuboCop::AST::Node
  const_assign_name = extract_const_assignment(node)
  return unless const_assign_name

  # When the assigned value is itself a constant reference, the assignment is an
  # alias (e.g. `Foo = Bar::Baz`). Track the target so member access through the
  # alias (`Foo::QUX`) can be resolved to the real constant later.
  value_node = node.children[2]
  alias_target = nil
  if value_node.kind_of?(RuboCop::AST::Node) && value_node.type == :const
    consts = find_consts(value_node)
    alias_target = consts.join('::') if consts
  end

  self.timeline << { event: :const_assign, name: const_assign_name, alias_target: alias_target }

  { skip: node.children }
end

#process_definition(node, _source) ⇒ Object 



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# File 'lib/rubocop/cop/require/missing_require_statement.rb', line 142

def process_definition(node, _source)
  if node.kind_of? Hash
    self.timeline << node
    return
  end

  return unless is_module_or_class?(node)
  name = find_consts(node.children.first).join('::')
  inherited = find_consts(node.children[1]).join('::') if has_superclass?(node)

  # Inheritance technically has to happen before the actual class definition
  self.timeline << { event: :const_inherit, name: inherited, node: node } if inherited

  self.timeline << { event: :const_def, name: name }

  # First child is the module/class name => skip or it'll be picked up by `process_const`
  skip_list = [node.children.first]
  skip_list << node.children[1] if inherited

  push_list = []
  push_list << { event: :const_undef, name: name }

  { skip: skip_list, push: push_list }
end

#process_require(node, source) ⇒ Object 



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# File 'lib/rubocop/cop/require/missing_require_statement.rb', line 171

def process_require(node, source)
  return unless node.kind_of? RuboCop::AST::Node
  required = extract_require(node)
  return unless required && required.length == 2
  method, file = required
  self.timeline << { event: method, file: file, path: source.path }

  { skip: node.children }
end