Class: Mutante::LineAnalyzer

Inherits:
Object
  • Object
show all
Defined in:
lib/mutante/line_analyzer.rb

Overview

Walks a file line-by-line, yielding an opportunity to comment each eligible line out. The file is rewritten for each trial and restored afterwards — callers get a block that runs while the file is mutated.

Constant Summary collapse

SKIP_EXACT =

Lines that are pure structural keywords would break the syntax the moment they are commented out, so we skip them up front.

%w[
  end else elsif ensure rescue begin do then
].freeze

Instance Method Summary collapse

Constructor Details

#initialize(path) ⇒ LineAnalyzer

Returns a new instance of LineAnalyzer.



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# File 'lib/mutante/line_analyzer.rb', line 12

def initialize(path)
  @path          = path
  @original_lines = File.readlines(path)
end

Instance Method Details

#each_candidate ⇒ Object

Yields |line_number, line_text| for each line worth trying. Inside the block, the file on disk has that line commented out. After the block returns, the file is restored to its original form.



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# File 'lib/mutante/line_analyzer.rb', line 20

def each_candidate
  @original_lines.each_with_index do |line, index|
    next unless candidate?(line)

    commented = commented_version(line)
    next unless still_valid_ruby?(index, commented)

    write_with_substitution(index, commented)
    begin
      yield(index + 1, line.chomp)
    ensure
      restore_original
    end
  end
end