[Fix #5708] Handle comment rubocop:enable all bug (#5810)

CHANGELOG.md

@@ -30,6 +30,7 @@
 * [#5809](https://github.com/bbatsov/rubocop/issues/5809): Fix exception `Lint/PercentStringArray` and `Lint/PercentSymbolArray` when the inspected file is binary encoded. ([@akhramov][])
 * [#5840](https://github.com/bbatsov/rubocop/issues/5840): Do not register an offense for methods that `nil` responds to in `Lint/SafeNavigationConsistency`. ([@rrosenblum][])
 * [#5862](https://github.com/bbatsov/rubocop/issues/5862): Fix an incorrect auto-correct for `Lint/LiteralInInterpolation` if contains numbers. ([@koic][])
+* [#5708](https://github.com/bbatsov/rubocop/issues/5708): Fix exception in `Lint/UnneededCopEnableDirective` for instruction '# rubocop:enable **all**'. ([@balbesina][])
 * Fix auto-correction of `Rails/HttpPositionalArgumnets` to use `session` instead of `header`. ([@rrosenblum][])
 
 ### Changes
@@ -3360,3 +3361,4 @@
 [@JacobEvelyn]: https://github.com/JacobEvelyn
 [@shanecav84]: https://github.com/shanecav84
 [@thomasbrus]: https://github.com/thomasbrus
+[@balbesina]: https://github.com/balbesina

lib/rubocop/comment_config.rb

@@ -43,17 +43,14 @@ def extra_enabled_comments
     def extra_enabled_comments_with_names(extras, names)
       each_directive do |comment, cop_names, disabled|
         next unless comment_only_line?(comment.loc.expression.line)
-        cop_names.each do |name|
-          names[name] ||= 0
-          if disabled
-            names[name] += 1
-          elsif names[name] > 0
-            names[name] -= 1
-          else
-            extras << [comment, name]
-          end
+
+        if !disabled && enable_all?(comment)
+          handle_enable_all(names, extras, comment)
+        else
+          handle_switch(cop_names, names, disabled, extras, comment)
         end
       end
+
       extras
     end
 
@@ -169,5 +166,35 @@ def non_comment_token_line_numbers
         non_comment_tokens.map(&:line).uniq
       end
     end
+
+    def enable_all?(comment)
+      _, cops = comment.text.match(COMMENT_DIRECTIVE_REGEXP).captures
+      cops == 'all'
+    end
+
+    def handle_enable_all(names, extras, comment)
+      enabled_cops = 0
+      names.each do |name, counter|
+        next unless counter > 0
+
+        names[name] -= 1
+        enabled_cops += 1
+      end
+
+      extras << [comment, 'all'] if enabled_cops.zero?
+    end
+
+    def handle_switch(cop_names, names, disabled, extras, comment)
+      cop_names.each do |name|
+        names[name] ||= 0
+        if disabled
+          names[name] += 1
+        elsif names[name] > 0
+          names[name] -= 1
+        else
+          extras << [comment, name]
+        end
+      end
+    end
   end
 end

lib/rubocop/cop/lint/unneeded_cop_enable_directive.rb

@@ -10,13 +10,28 @@ module Lint
       # This cop detects instances of rubocop:enable comments that can be
       # removed.
       #
+      # When comment enables all cops at once `rubocop:enable all`
+      # that cop checks whether any cop was actually enabled.
       # @example
       #   # bad
       #   foo = 1
       #   # rubocop:enable Metrics/LineLength
       #
       #   # good
       #   foo = 1
+      # @example
+      #   # bad
+      #   # rubocop:disable Metrics/LineLength
+      #   baaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaarrrrrrrrrrrrr
+      #   # rubocop:enable Metrics/LineLength
+      #   baz
+      #   # rubocop:enable all
+      #
+      #   # good
+      #   # rubocop:disable Metrics/LineLength
+      #   baaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaarrrrrrrrrrrrr
+      #   # rubocop:enable all
+      #   baz
       class UnneededCopEnableDirective < Cop
         include RangeHelp
         include SurroundingSpace
@@ -30,7 +45,7 @@ def investigate(processed_source)
             add_offense(
               [comment, name],
               location: range_of_offense(comment, name),
-              message: format(MSG, cop: name)
+              message: format(MSG, cop: all_or_name(name))
             )
           end
         end
@@ -90,8 +105,11 @@ def range_to_remove(begin_pos, end_pos, comma_pos, comment)
             range_class.new(buffer, start, comment.loc.expression.end_pos)
           end
         end
+
+        def all_or_name(name)
+          name == 'all' ? 'all cops' : name
+        end
       end
     end
   end
 end
-# rubocop:enable Lint/UnneededCopEnableDirective

manual/cops_lint.md

@@ -2042,6 +2042,9 @@ Enabled | Yes
 This cop detects instances of rubocop:enable comments that can be
 removed.
 
+When comment enables all cops at once `rubocop:enable all`
+that cop checks whether any cop was actually enabled.
+
 ### Examples
 
 ```ruby
@@ -2052,6 +2055,20 @@ foo = 1
 # good
 foo = 1
 ```
+```ruby
+# bad
+# rubocop:disable Metrics/LineLength
+baaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaarrrrrrrrrrrrr
+# rubocop:enable Metrics/LineLength
+baz
+# rubocop:enable all
+
+# good
+# rubocop:disable Metrics/LineLength
+baaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaarrrrrrrrrrrrr
+# rubocop:enable all
+baz
+```
 
 ## Lint/UnneededRequireStatement
 

spec/rubocop/cop/lint/unneeded_cop_enable_directive_spec.rb

@@ -45,6 +45,26 @@
     RUBY
   end
 
+  context 'all switch' do
+    it 'registers offense for unnecessary enable all' do
+      expect_offense(<<-RUBY.strip_indent)
+      foo
+      # rubocop:enable all
+                       ^^^ Unnecessary enabling of all cops.
+      RUBY
+    end
+
+    context 'when at least one cop was disabled' do
+      it 'does not register offence' do
+        expect_no_offenses(<<-RUBY.strip_indent)
+        # rubocop:disable Metrics/LineLength
+        foooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooo
+        # rubocop:enable all
+        RUBY
+      end
+    end
+  end
+
   context 'autocorrection' do
     context 'when entire comment unnecessarily enables' do
       let(:source) do