Class: Rubocop::Cop::Blocks

Inherits:
Cop
  • Object
show all
Defined in:
lib/rubocop/cop/blocks.rb

Constant Summary collapse

ERROR_MESSAGE = 
['Avoid using {...} for multi-line blocks.',
'Prefer {...} over do...end for single-line blocks.']

Instance Attribute Summary

Attributes inherited from Cop

#correlations, #offences

Instance Method Summary collapse

Methods inherited from Cop

#add_offence, enabled?, #has_report?, inherited, #initialize

Constructor Details

This class inherits a constructor from Rubocop::Cop::Cop

Instance Method Details

#inspect(file, source, tokens, sexp) ⇒ Object 



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# File 'lib/rubocop/cop/blocks.rb', line 9

def inspect(file, source, tokens, sexp)
  @file = file

  # The reverse_correlations maps grammar path object ids to
  # token indexes, so we can use it to find the corresponding }
  # for each {.
  reverse_correlations = Hash.new([])
  @correlations.each do |ix, path|
    reverse_correlations[path.object_id] += [ix]
  end
  tokens.each_with_index do |t, ix|
    case [t.type, t.text]
    when [:on_lbrace, '{']
      path = @correlations[ix] or next
      if path.last == :brace_block
        rbrace_ix = reverse_correlations[path.object_id] - [ix]
        if rbrace_ix.empty?
          fail "\n#@file:#{t.pos.lineno}:#{t.pos.column}: " +
            'Matching brace not found'
        end
        if tokens[*rbrace_ix].pos.lineno > t.pos.lineno
          add_offence(:convention, t.pos.lineno, ERROR_MESSAGE[0])
        end
      end
    when [:on_kw, 'do']
      end_offset = tokens[ix..-1].index { |t2| t2.text == 'end' }
      unless end_offset
        fail "\n#@file:#{t.pos.lineno}:#{t.pos.column}: " +
          'Matching end not found'
      end
      end_token_ix = ix + end_offset
      if tokens[end_token_ix].pos.lineno == t.pos.lineno
        add_offence(:convention, t.pos.lineno, ERROR_MESSAGE[1])
      end
    end
  end
end