Class: RuboCop::Cop::Style::FileRead

Inherits:
Base
  • Object
show all
Extended by:
AutoCorrector
Includes:
RangeHelp
Defined in:
lib/rubocop/cop/style/file_read.rb

Overview

Favor ‘File.(bin)read` convenience methods.

Examples:

# bad - text mode
File.open(filename).read
File.open(filename, &:read)
File.open(filename) { |f| f.read }
File.open(filename) do |f|
  f.read
end
File.open(filename, 'r').read
File.open(filename, 'r', &:read)
File.open(filename, 'r') do |f|
  f.read
end

# good
File.read(filename)

# bad - binary mode
File.open(filename, 'rb').read
File.open(filename, 'rb', &:read)
File.open(filename, 'rb') do |f|
  f.read
end

# good
File.binread(filename)

Constant Summary collapse

MSG = 
'Use `File.%<read_method>s`.'
RESTRICT_ON_SEND = 
%i[open].freeze
READ_FILE_START_TO_FINISH_MODES = 
%w[r rt rb r+ r+t r+b].to_set.freeze

Instance Method Summary collapse

Methods included from AutoCorrector

support_autocorrect?

Instance Method Details

#block_read?(node) ⇒ Object 



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# File 'lib/rubocop/cop/style/file_read.rb', line 62

def_node_matcher :block_read?, <<~PATTERN
  (block _ (args (arg _name)) (send (lvar _name) :read))
PATTERN

#file_open?(node) ⇒ Object 



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# File 'lib/rubocop/cop/style/file_read.rb', line 46

def_node_matcher :file_open?, <<~PATTERN
  (send
    (const {nil? cbase} :File)
    :open
    $_
    (str $%READ_FILE_START_TO_FINISH_MODES)?
    $(block-pass (sym :read))?
  )
PATTERN

#on_send(node) ⇒ Object 



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# File 'lib/rubocop/cop/style/file_read.rb', line 66

def on_send(node)
  evidence(node) do |filename, mode, read_node|
    message = format(MSG, read_method: read_method(mode))

    add_offense(read_node, message: message) do |corrector|
      range = range_between(node.loc.selector.begin_pos, read_node.source_range.end_pos)
      replacement = "#{read_method(mode)}(#{filename.source})"

      corrector.replace(range, replacement)
    end
  end
end

#send_read?(node) ⇒ Object 



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# File 'lib/rubocop/cop/style/file_read.rb', line 57

def_node_matcher :send_read?, <<~PATTERN
  (send _ :read)
PATTERN