False positive with DeletePrefix

[avdv]

For a multi-line string, I am using gsub(/^ /, '') and I receive a wrong suggestion that I should replace this call with delete_prefix.

Note that ^ matches at the beginning of a line, not only at the beginning of the string.

---

Expected behavior

No offense being reported.

Actual behavior

lib/colorls/flags.rb:169:23: C: Performance/DeletePrefix: Use delete_prefix instead of gsub.

      puts <<EXAMPLES.gsub(/^  /, '')

                      ^^^^

Steps to reproduce the problem

def show_examples
      puts <<EXAMPLES.gsub(/^  /, '')

  examples:

    * show the given file:

      colorls README.md

    * show matching files and list matching directories:

EXAMPLES
    end

RuboCop version

0.84.0 (using Parser 2.7.1.2, rubocop-ast 0.0.3, running on ruby 2.6.6 x86_64-linux)

[mattbrictson]

I believe the same bug exists for Performance/StartWith.

# This checks that _any_ line in the output starts with "origin"
`git remote -v`.match?(/^origin/)

#  Performance/StartWith suggests this, which only tests the first line
`git remote -v`.start_with?("origin")

[mattbrictson]

I think the fix is that both cops should only flag patterns that start with \A (not ^).

[avdv]

I think the fix is that both cops should only flag patterns that start with \A (not ^).

Yes, same goes for $ and \Z in regard to the delete suffix and end with cops.