Performance/ConstantRegexp and Performance/RegexpMatch interact badly when autocorrecting

[pvande]

When both the ConstantRegexp and RegexpMatch cops have violations on the same line, the ConstantRegexp cop may make multiple corrections on the same line, breaking existing code.

---

Steps to reproduce the problem

Given this configuration:

# .rubocop.yml
require:
  - rubocop-performance

AllCops:
  DisabledByDefault: true

Performance/RegexpMatch:
  Enabled: true
Performance/ConstantRegexp:
  Enabled: true

And given this source file:

CONSTANT = "12345"

if content =~ /#{CONSTANT}.*\n/
  thing
end

Rubocop describes the following offenses:

# rubocop test.rb
Inspecting 1 file
C

Offenses:

test.rb:3:4: C: [Correctable] Performance/RegexpMatch: Use match? instead of =~ when MatchData is not used.
if content =~ /#{CONSTANT}.*\n/
   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
test.rb:3:15: C: [Correctable] Performance/ConstantRegexp: Extract this regexp into a constant, memoize it, or append an /o option to its options.
if content =~ /#{CONSTANT}.*\n/
              ^^^^^^^^^^^^^^^^^

1 file inspected, 2 offenses detected, 2 offenses autocorrectable

This is all as expected.

Running this with the --autocorrect/-a flag, however, generates a different report.

# rubocop -a test.rb
Inspecting 1 file
C

Offenses:

test.rb:3:4: C: [Corrected] Performance/ConstantRegexp: Extract this regexp into a constant, memoize it, or append an /o option to its options.
if /#{CONSTANT}.*\n/.match?(contento)
   ^^^^^^^^^^^^^^^^^
test.rb:3:4: C: [Corrected] Performance/RegexpMatch: Use match? instead of =~ when MatchData is not used.
if content =~ /#{CONSTANT}.*\n/
   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
test.rb:3:15: C: [Corrected] Performance/ConstantRegexp: Extract this regexp into a constant, memoize it, or append an /o option to its options.
if content =~ /#{CONSTANT}.*\n/
              ^^^^^^^^^^^^^^^^^

1 file inspected, 3 offenses detected, 3 offenses corrected

Note that the bottom-most entry reports an issue pre-RegexpMatch, and the top-most entry reports post-RegexpMatch. Also note that the top-most entry is matching against contento (not content). The resulting file is as follows:

CONSTANT = "12345"

if /#{CONSTANT}.*\n/o.match?(contento)
  thing
end

Since the content variable has been changed to contento, the autocorrected file has semantically changed.

RuboCop version

# rubocop -V
1.49.0 (using Parser 3.2.2.0, rubocop-ast 1.28.0, running on ruby 3.2.0) [aarch64-linux-musl]
  - rubocop-performance 1.16.0