Class: RuboCop::Cop::Performance::EmptyGsubReplacement

Inherits:
RuboCop::Cop
  • Object
show all
Defined in:
lib/rubocop-aha/cop/performance/empty_gsub_replacement.rb

Overview

This cop identifies places where ‘gsub` can be replaced by `delete`.

Examples:

@bad
'abc'.gsub('b', 'd')
'abc'.gsub('a', '')
'abc'.gsub(/a/, 'd')
'abc'.gsub!('a', 'd')

@good
'abc'.gsub(/.*/, 'a')
'abc'.gsub(/a+/, 'd')
'a b c'.delete(' ')

Constant Summary collapse

MSG = 
'Use `%s` instead of `%s`.'.freeze
DETERMINISTIC_REGEX = 
/\A(?:#{LITERAL_REGEX})+\Z/
DELETE = 
'delete'.freeze
BANG = 
'!'.freeze
SINGLE_QUOTE = 
"'".freeze

Instance Method Summary collapse

Instance Method Details

#autocorrect(node) ⇒ Object 



43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
 
# File 'lib/rubocop-aha/cop/performance/empty_gsub_replacement.rb', line 43

def autocorrect(node)
  _string, _method, first_param, second_param = *node
  first_source, = first_source(first_param)
  second_source, = *second_param

  unless first_param.str_type?
    first_source = interpret_string_escapes(first_source)
  end

  replacement_method =
    replacement_method(node, first_source, second_source)

  replace_method(node, first_source, second_source, first_param,
                 replacement_method)
end

#on_send(node) ⇒ Object 



34
35
36
37
38
39
40
41
 
# File 'lib/rubocop-aha/cop/performance/empty_gsub_replacement.rb', line 34

def on_send(node)
  string_replacement?(node) do |first_param, second_param|
    return if accept_second_param?(second_param)
    return if accept_first_param?(first_param)
    
    offense(node, first_param, second_param)
  end
end

#replace_method(node, first, second, first_param, replacement) ⇒ Object 



59
60
61
62
63
64
65
66
67
68
69
70
71
 
# File 'lib/rubocop-aha/cop/performance/empty_gsub_replacement.rb', line 59

def replace_method(node, first, second, first_param, replacement)
  lambda do |corrector|
    corrector.replace(node.loc.selector, replacement)
    unless first_param.str_type?
      corrector.replace(first_param.source_range,
                        to_string_literal(first))
    end

    if second.empty? && first.length == 1
      remove_second_param(corrector, node, first_param)
    end
  end
end