Merge pull request #8527 from koic/fix_incorrect_autocorrect_for_styl…

…e_case_equality Prevent an incorrect auto-correction for `Style/CaseEquality` cop
rubocop · Aug 17, 2020 · a2c6a94 · a2c6a94
2 parents 2845f8d + d771985
commit a2c6a94
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diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -14,6 +14,7 @@
 * [#8534](https://github.com/rubocop-hq/rubocop/issues/8534): Fix `Lint/BinaryOperatorWithIdenticalOperands` for binary operators used as unary operators. ([@marcandre][])
 * [#8537](https://github.com/rubocop-hq/rubocop/pull/8537): Allow a trailing comment as a description comment for `Bundler/GemComment`. ([@pocke][])
 * [#8507](https://github.com/rubocop-hq/rubocop/issues/8507): Fix `Style/RescueModifier` to handle parentheses around rescue modifiers. ([@dsavochkin][])
+* [#8527](https://github.com/rubocop-hq/rubocop/pull/8527): Prevent an incorrect auto-correction for `Style/CaseEquality` cop when comparing with `===` against a regular expression receiver. ([@koic][])
 
 ### Changes
 

diff --git a/docs/modules/ROOT/pages/cops_style.adoc b/docs/modules/ROOT/pages/cops_style.adoc
@@ -825,7 +825,7 @@ Array === something
 # good
 something.is_a?(Array)
 (1..100).include?(7)
-some_string =~ /something/
+/something/.match?(some_string)
 ----
 
 ==== AllowOnConstant
@@ -842,7 +842,7 @@ some_string =~ /something/
 # good
 Array === something
 (1..100).include?(7)
-some_string =~ /something/
+/something/.match?(some_string)
 ----
 
 === Configurable attributes

diff --git a/lib/rubocop/cop/style/case_equality.rb b/lib/rubocop/cop/style/case_equality.rb
@@ -14,7 +14,7 @@ module Style
       #   # good
       #   something.is_a?(Array)
       #   (1..100).include?(7)
-      #   some_string =~ /something/
+      #   /something/.match?(some_string)
       #
       # @example AllowOnConstant
       #   # Style/CaseEquality:
@@ -27,7 +27,7 @@ module Style
       #   # good
       #   Array === something
       #   (1..100).include?(7)
-      #   some_string =~ /something/
+      #   /something/.match?(some_string)
       #
       class CaseEquality < Base
         extend AutoCorrector
@@ -58,7 +58,12 @@ def const?(node)
         def replacement(lhs, rhs)
           case lhs.type
           when :regexp
-            "#{rhs.source} =~ #{lhs.source}"
+            # The automatic correction from `a === b` to `a.match?(b)` needs to
+            # consider `Regexp.last_match?`, `$~`, `$1`, and etc.
+            # This correction is expected to be supported by `Performance/Regexp` cop.
+            # See: https://github.com/rubocop-hq/rubocop-performance/issues/152
+            #
+            # So here is noop.
           when :begin
             child = lhs.children.first
             "#{lhs.source}.include?(#{rhs.source})" if child&.range_type?

diff --git a/spec/rubocop/cop/style/case_equality_spec.rb b/spec/rubocop/cop/style/case_equality_spec.rb
@@ -14,9 +14,8 @@
               ^^^ Avoid the use of the case equality operator `===`.
       RUBY
 
-      expect_correction(<<~RUBY)
-        var =~ /OMG/
-      RUBY
+      # This correction is expected to be supported by `Performance/Regexp`.
+      expect_no_corrections
     end
 
     it 'registers an offense and corrects for === when the receiver is a range' do