Class: RuboCop::Cop::Rails::Blank

Inherits:
RuboCop::Cop show all
Defined in:
lib/rubocop/cop/rails/blank.rb

Overview

This cop checks for code that can be written with simpler conditionals using ‘Object#blank?` defined by Active Support.

Interaction with ‘Style/UnlessElse`: The configuration of `NotPresent` will not produce an offense in the context of `unless else` if `Style/UnlessElse` is inabled. This is to prevent interference between the auto-correction of the two cops.

Examples:

NilOrEmpty: true (default)

# Converts usages of `nil? || empty?` to `blank?`

# bad
foo.nil? || foo.empty?
foo == nil || foo.empty?

# good
foo.blank?

NotPresent: true (default)

# Converts usages of `!present?` to `blank?`

# bad
!foo.present?

# good
foo.blank?

UnlessPresent: true (default)

# Converts usages of `unless present?` to `if blank?`

# bad
something unless foo.present?

# good
something if foo.blank?

# bad
unless foo.present?
  something
end

# good
if foo.blank?
  something
end

# good
def blank?
  !present?
end

Constant Summary collapse

MSG_NIL_OR_EMPTY = 
'Use `%<prefer>s` instead of `%<current>s`.'
MSG_NOT_PRESENT = 
'Use `%<prefer>s` instead of `%<current>s`.'
MSG_UNLESS_PRESENT = 
'Use `if %<prefer>s` instead of ' \
'`%<current>s`.'

Instance Method Summary collapse

Instance Method Details

#autocorrect(node) ⇒ Object 



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# File 'lib/rubocop/cop/rails/blank.rb', line 132

def autocorrect(node)
  lambda do |corrector|
    method_call, variable1 = unless_present?(node)

    if method_call
      corrector.replace(node.loc.keyword, 'if')
      range = method_call.loc.expression
    else
      variable1, _variable2 = nil_or_empty?(node) || not_present?(node)
      range = node.loc.expression
    end

    corrector.replace(range, replacement(variable1))
  end
end

#on_if(node) ⇒ Object 



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# File 'lib/rubocop/cop/rails/blank.rb', line 116

def on_if(node)
  return unless cop_config['UnlessPresent']
  return unless node.unless?
  return if node.else? && config.for_cop('Style/UnlessElse')['Enabled']

  unless_present?(node) do |method_call, receiver|
    range = unless_condition(node, method_call)

    add_offense(node,
                location: range,
                message: format(MSG_UNLESS_PRESENT,
                                prefer: replacement(receiver),
                                current: range.source))
  end
end

#on_or(node) ⇒ Object 



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# File 'lib/rubocop/cop/rails/blank.rb', line 103

def on_or(node)
  return unless cop_config['NilOrEmpty']

  nil_or_empty?(node) do |var1, var2|
    return unless var1 == var2

    add_offense(node,
                message: format(MSG_NIL_OR_EMPTY,
                                prefer: replacement(var1),
                                current: node.source))
  end
end

#on_send(node) ⇒ Object 



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# File 'lib/rubocop/cop/rails/blank.rb', line 89

def on_send(node)
  return unless cop_config['NotPresent']

  not_present?(node) do |receiver|
    # accepts !present? if its in the body of a `blank?` method
    next if defining_blank?(node.parent)

    add_offense(node,
                message: format(MSG_NOT_PRESENT,
                                prefer: replacement(receiver),
                                current: node.source))
  end
end