/
redundant_cop_disable_directive.rb
260 lines (225 loc) · 9.69 KB
/
redundant_cop_disable_directive.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
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
# frozen_string_literal: true
# The Lint/RedundantCopDisableDirective cop needs to be disabled so as
# to be able to provide a (bad) example of a redundant disable.
# rubocop:disable Lint/RedundantCopDisableDirective
module RuboCop
module Cop
module Lint
# This cop detects instances of rubocop:disable comments that can be
# removed without causing any offenses to be reported. It's implemented
# as a cop in that it inherits from the Cop base class and calls
# add_offense. The unusual part of its implementation is that it doesn't
# have any on_* methods or an investigate method. This means that it
# doesn't take part in the investigation phase when the other cops do
# their work. Instead, it waits until it's called in a later stage of the
# execution. The reason it can't be implemented as a normal cop is that
# it depends on the results of all other cops to do its work.
#
#
# @example
# # bad
# # rubocop:disable Layout/LineLength
# x += 1
# # rubocop:enable Layout/LineLength
#
# # good
# x += 1
class RedundantCopDisableDirective < Cop
include RangeHelp
COP_NAME = 'Lint/RedundantCopDisableDirective'
def check(offenses, cop_disabled_line_ranges, comments)
redundant_cops = Hash.new { |h, k| h[k] = Set.new }
each_redundant_disable(cop_disabled_line_ranges,
offenses, comments) do |comment, redundant_cop|
redundant_cops[comment].add(redundant_cop)
end
add_offenses(redundant_cops)
end
def autocorrect(args)
lambda do |corrector|
ranges, range = *args # Ranges are sorted by position.
range = if range.source.start_with?('#')
comment_range_with_surrounding_space(range)
else
directive_range_in_list(range, ranges)
end
corrector.remove(range)
end
end
private
def comment_range_with_surrounding_space(range)
# Eat the entire comment, the preceding space, and the preceding
# newline if there is one.
original_begin = range.begin_pos
range = range_with_surrounding_space(range: range,
side: :left,
newlines: true)
range_with_surrounding_space(range: range,
side: :right,
# Special for a comment that
# begins the file: remove
# the newline at the end.
newlines: original_begin.zero?)
end
def directive_range_in_list(range, ranges)
# Is there any cop between this one and the end of the line, which
# is NOT being removed?
if ends_its_line?(ranges.last) && trailing_range?(ranges, range)
# Eat the comma on the left.
range = range_with_surrounding_space(range: range, side: :left)
range = range_with_surrounding_comma(range, :left)
end
range = range_with_surrounding_comma(range, :right)
# Eat following spaces up to EOL, but not the newline itself.
range_with_surrounding_space(range: range,
side: :right,
newlines: false)
end
def each_redundant_disable(cop_disabled_line_ranges, offenses, comments,
&block)
disabled_ranges = cop_disabled_line_ranges[COP_NAME] || [0..0]
cop_disabled_line_ranges.each do |cop, line_ranges|
each_already_disabled(line_ranges,
disabled_ranges, comments) do |comment|
yield comment, cop
end
each_line_range(line_ranges, disabled_ranges, offenses, comments,
cop, &block)
end
end
def each_line_range(line_ranges, disabled_ranges, offenses, comments,
cop)
line_ranges.each_with_index do |line_range, ix|
comment = comments.find { |c| c.loc.line == line_range.begin }
next if ignore_offense?(disabled_ranges, line_range)
redundant_cop = find_redundant(comment, offenses, cop, line_range,
line_ranges[ix + 1])
yield comment, redundant_cop if redundant_cop
end
end
def each_already_disabled(line_ranges, disabled_ranges, comments)
line_ranges.each_cons(2) do |previous_range, range|
next if ignore_offense?(disabled_ranges, range)
next if previous_range.end != range.begin
# If a cop is disabled in a range that begins on the same line as
# the end of the previous range, it means that the cop was
# already disabled by an earlier comment. So it's redundant
# whether there are offenses or not.
redundant_comment = comments.find do |c|
c.loc.line == range.begin &&
# Comments disabling all cops don't count since it's reasonable
# to disable a few select cops first and then all cops further
# down in the code.
!all_disabled?(c)
end
yield redundant_comment if redundant_comment
end
end
# rubocop:todo Metrics/CyclomaticComplexity
def find_redundant(comment, offenses, cop, line_range, next_line_range)
if all_disabled?(comment)
# If there's a disable all comment followed by a comment
# specifically disabling `cop`, we don't report the `all`
# comment. If the disable all comment is truly redundant, we will
# detect that when examining the comments of another cop, and we
# get the full line range for the disable all.
if (next_line_range.nil? ||
line_range.last != next_line_range.first) &&
offenses.none? { |o| line_range.cover?(o.line) }
'all'
end
else
cop_offenses = offenses.select { |o| o.cop_name == cop }
cop if cop_offenses.none? { |o| line_range.cover?(o.line) }
end
end
# rubocop:enable Metrics/CyclomaticComplexity
def all_disabled?(comment)
/rubocop\s*:\s*(?:disable|todo)\s+all\b/.match?(comment.text)
end
def ignore_offense?(disabled_ranges, line_range)
disabled_ranges.any? do |range|
range.cover?(line_range.min) && range.cover?(line_range.max)
end
end
def directive_count(comment)
match = comment.text.match(CommentConfig::COMMENT_DIRECTIVE_REGEXP)
_, cops_string = match.captures
cops_string.split(/,\s*/).size
end
def add_offenses(redundant_cops)
redundant_cops.each do |comment, cops|
if all_disabled?(comment) ||
directive_count(comment) == cops.size
add_offense_for_entire_comment(comment, cops)
else
add_offense_for_some_cops(comment, cops)
end
end
end
def add_offense_for_entire_comment(comment, cops)
location = comment.loc.expression
cop_list = cops.sort.map { |c| describe(c) }
add_offense(
[[location], location],
location: location,
message: "Unnecessary disabling of #{cop_list.join(', ')}."
)
end
def add_offense_for_some_cops(comment, cops)
cop_ranges = cops.map { |c| [c, cop_range(comment, c)] }
cop_ranges.sort_by! { |_, r| r.begin_pos }
ranges = cop_ranges.map { |_, r| r }
cop_ranges.each do |cop, range|
add_offense(
[ranges, range],
location: range,
message: "Unnecessary disabling of #{describe(cop)}."
)
end
end
def cop_range(comment, cop)
matching_range(comment.loc.expression, cop) ||
matching_range(comment.loc.expression, Badge.parse(cop).cop_name) ||
raise("Couldn't find #{cop} in comment: #{comment.text}")
end
def matching_range(haystack, needle)
offset = haystack.source.index(needle)
return unless offset
offset += haystack.begin_pos
Parser::Source::Range.new(haystack.source_buffer, offset,
offset + needle.size)
end
def trailing_range?(ranges, range)
ranges
.drop_while { |r| !r.equal?(range) }
.each_cons(2)
.map { |range1, range2| range1.end.join(range2.begin).source }
.all? { |intervening| /\A\s*,\s*\Z/.match?(intervening) }
end
def describe(cop)
if cop == 'all'
'all cops'
elsif all_cop_names.include?(cop)
"`#{cop}`"
else
similar = NameSimilarity.find_similar_name(cop, all_cop_names)
if similar
"`#{cop}` (did you mean `#{similar}`?)"
else
"`#{cop}` (unknown cop)"
end
end
end
def all_cop_names
@all_cop_names ||= Cop.registry.names
end
def ends_its_line?(range)
line = range.source_buffer.source_line(range.last_line)
(line =~ /\s*\z/) == range.last_column
end
end
end
end
end
# rubocop:enable Lint/RedundantCopDisableDirective