/
and_or.rb
153 lines (131 loc) · 4.47 KB
/
and_or.rb
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
# frozen_string_literal: true
module RuboCop
module Cop
module Style
# This cop checks for uses of `and` and `or`, and suggests using `&&` and
# `||` instead. It can be configured to check only in conditions or in
# all contexts.
#
# @example EnforcedStyle: always
# # bad
# foo.save and return
#
# # bad
# if foo and bar
# end
#
# # good
# foo.save && return
#
# # good
# if foo && bar
# end
#
# @example EnforcedStyle: conditionals (default)
# # bad
# if foo and bar
# end
#
# # good
# foo.save && return
#
# # good
# foo.save and return
#
# # good
# if foo && bar
# end
class AndOr < Base
include ConfigurableEnforcedStyle
include RangeHelp
extend AutoCorrector
MSG = 'Use `%<prefer>s` instead of `%<current>s`.'
def on_and(node)
process_logical_operator(node) if style == :always
end
alias on_or on_and
def on_if(node)
on_conditionals(node) if style == :conditionals
end
alias on_while on_if
alias on_while_post on_if
alias on_until on_if
alias on_until_post on_if
private
def process_logical_operator(node)
return if node.logical_operator?
message = message(node)
add_offense(node.loc.operator, message: message) do |corrector|
node.each_child_node do |expr|
if expr.send_type?
correct_send(expr, corrector)
elsif expr.return_type? || expr.assignment?
correct_other(expr, corrector)
end
end
corrector.replace(node.loc.operator, node.alternate_operator)
keep_operator_precedence(corrector, node)
end
end
def on_conditionals(node)
node.condition.each_node(*AST::Node::OPERATOR_KEYWORDS) do |operator|
process_logical_operator(operator)
end
end
def message(node)
format(MSG, prefer: node.alternate_operator, current: node.operator)
end
def correct_send(node, corrector)
return correct_not(node, node.receiver, corrector) if node.method?(:!)
return correct_setter(node, corrector) if node.setter_method?
return correct_other(node, corrector) if node.comparison_method?
return unless correctable_send?(node)
whitespace_before_arg_range = whitespace_before_arg(node)
corrector.remove(whitespace_before_arg_range)
corrector.insert_before(whitespace_before_arg_range, '(')
corrector.insert_after(node.last_argument, ')')
end
def correct_setter(node, corrector)
corrector.insert_before(node.receiver, '(')
corrector.insert_after(node.last_argument, ')')
end
# ! is a special case:
# 'x and !obj.method arg' can be auto-corrected if we
# recurse down a level and add parens to 'obj.method arg'
# however, 'not x' also parses as (send x :!)
def correct_not(node, receiver, corrector)
if node.prefix_bang?
return unless receiver.send_type?
correct_send(receiver, corrector)
elsif node.prefix_not?
correct_other(node, corrector)
else
raise 'unrecognized unary negation operator'
end
end
def correct_other(node, corrector)
return if node.source_range.begin.is?('(')
corrector.wrap(node, '(', ')')
end
def keep_operator_precedence(corrector, node)
if node.or_type? && node.parent&.and_type?
corrector.wrap(node, '(', ')')
elsif node.and_type? && node.rhs.or_type?
corrector.wrap(node.rhs, '(', ')')
end
end
def correctable_send?(node)
!node.parenthesized? && node.arguments? && !node.method?(:[])
end
def whitespace_before_arg(node)
begin_paren = node.loc.selector.end_pos
end_paren = begin_paren
# Increment position of parenthesis, unless message is a predicate
# method followed by a non-whitespace char (e.g. is_a?String).
end_paren += 1 unless /\?\S/.match?(node.source)
range_between(begin_paren, end_paren)
end
end
end
end
end