Class: RuboCop::AST::IfNode

Inherits:
Node
  • Object
show all
Includes:
ConditionalNode, ModifierNode
Defined in:
lib/rubocop/ast/node/if_node.rb

Overview

A node extension for ‘if` nodes. This will be used in place of a plain node when the builder constructs the AST, making its methods available to all `if` nodes within RuboCop.

Constant Summary

Constants inherited from Node

Node::BASIC_LITERALS, Node::COMPARISON_OPERATORS, Node::COMPOSITE_LITERALS, Node::FALSEY_LITERALS, Node::IMMUTABLE_LITERALS, Node::KEYWORDS, Node::LITERALS, Node::MUTABLE_LITERALS, Node::OPERATOR_KEYWORDS, Node::REFERENCES, Node::SPECIAL_KEYWORDS, Node::TRUTHY_LITERALS, Node::VARIABLES

Instance Method Summary collapse

Methods included from ConditionalNode

#body, #condition, #multiline_condition?, #single_line_condition?

Methods inherited from Node

#ancestors, #argument?, #asgn_method_call?, #basic_literal?, #binary_operation?, #chained?, #child_nodes, #complete!, #complete?, #const_name, #defined_module, #defined_module_name, #descendants, #each_ancestor, #each_child_node, #each_descendant, #each_node, #falsey_literal?, #immutable_literal?, #initialize, #keyword?, #keyword_bang?, #keyword_not?, #literal?, #multiline?, #mutable_literal?, #numeric_type?, #operator_keyword?, #parent, #parent_module_name, #pure?, #receiver, #reference?, #sibling_index, #single_line?, #source, #source_range, #special_keyword?, #truthy_literal?, #unary_operation?, #updated, #value_used?, #variable?

Methods included from NodePattern::Macros

#def_node_matcher, #def_node_search, #node_search, #node_search_all, #node_search_body, #node_search_first

Methods included from Sexp

#s

Constructor Details

This class inherits a constructor from RuboCop::AST::Node

Instance Method Details

#else? ⇒ Boolean

Note:

This returns ‘true` for nodes containing an `elsif` clause. This is legacy behavior, and many cops rely on it.

Checks whether the ‘if` node has an `else` clause.

Returns:

  • (Boolean) —

    whether the node has an ‘else` clause



42
43
44
 
# File 'lib/rubocop/ast/node/if_node.rb', line 42

def else?
  loc.respond_to?(:else) && loc.else
end

#else_branch ⇒ Node?

Note:

This is normalized for ‘unless` nodes.

Returns the branch of the ‘if` node that gets evaluated when its condition is falsey.

Returns:

  • (Node) —

    the falsey branch node of the ‘if` node

  • (nil) —

    when there is no else branch



127
128
129
 
# File 'lib/rubocop/ast/node/if_node.rb', line 127

def else_branch
  node_parts[2]
end

#elsif? ⇒ Boolean

Checks whether the ‘if` is an `elsif`. Parser handles these by nesting `if` nodes in the `else` branch.

Returns:

  • (Boolean) —

    whether the node is an ‘elsif`



32
33
34
 
# File 'lib/rubocop/ast/node/if_node.rb', line 32

def elsif?
  keyword == 'elsif'
end

#elsif_conditional? ⇒ Boolean

Checks whether the ‘if` node has at least one `elsif` branch. Returns true if this `if` node itself is an `elsif`.

Returns:

  • (Boolean) —

    whether the ‘if` node has at least one `elsif` branch



105
106
107
 
# File 'lib/rubocop/ast/node/if_node.rb', line 105

def elsif_conditional?
  else_branch && else_branch.if_type? && else_branch.elsif?
end

#if? ⇒ Boolean

Checks whether this node is an ‘if` statement. (This is not true of ternary operators and `unless` statements.)

Returns:

  • (Boolean) —

    whether the node is an ‘if` statement



16
17
18
 
# File 'lib/rubocop/ast/node/if_node.rb', line 16

def if?
  keyword == 'if'
end

#if_branch ⇒ Node?

Note:

This is normalized for ‘unless` nodes.

Returns the branch of the ‘if` node that gets evaluated when its condition is truthy.

Returns:

  • (Node) —

    the truthy branch node of the ‘if` node

  • (nil) —

    if the truthy branch is empty



116
117
118
 
# File 'lib/rubocop/ast/node/if_node.rb', line 116

def if_branch
  node_parts[1]
end

#inverse_keyword ⇒ String

Returns the inverse keyword of the ‘if` node as a string. Returns `if` for `unless` nodes and vice versa. Returns an empty string for ternary operators.

Returns:

  • (String) —

    the inverse keyword of the ‘if` statement



66
67
68
69
70
71
72
73
74
 
# File 'lib/rubocop/ast/node/if_node.rb', line 66

def inverse_keyword
  if keyword == 'if'
    'unless'
  elsif keyword == 'unless'
    'if'
  else
    ''
  end
end

#keyword ⇒ String

Returns the keyword of the ‘if` statement as a string. Returns an empty string for ternary operators.

Returns:

  • (String) —

    the keyword of the ‘if` statement



57
58
59
 
# File 'lib/rubocop/ast/node/if_node.rb', line 57

def keyword
  ternary? ? '' : loc.keyword.source
end

#modifier_form? ⇒ Boolean

Checks whether the ‘if` node is in a modifier form, i.e. a condition trailing behind an expression. Only `if` and `unless` nodes without other branches can be modifiers.

Returns:

  • (Boolean) —

    whether the ‘if` node is a modifier



81
82
83
 
# File 'lib/rubocop/ast/node/if_node.rb', line 81

def modifier_form?
  (if? || unless?) && super
end

#nested_conditional? ⇒ Boolean

Note:

This performs a shallow search.

Chacks whether the ‘if` node has nested `if` nodes in any of its branches.

Returns:

  • (Boolean) —

    whether the ‘if` node contains nested conditionals



91
92
93
94
95
96
97
98
99
 
# File 'lib/rubocop/ast/node/if_node.rb', line 91

def nested_conditional?
  node_parts[1..2].compact.each do |branch|
    branch.each_node(:if) do |nested|
      return true unless nested.elsif?
    end
  end

  false
end

#node_parts ⇒ Array<Node>

Custom destructuring method. This is used to normalize the branches for ‘if` and `unless` nodes, to aid comparisons and conversions.

Returns:

  • (Array<Node>) —

    the different parts of the ‘if` statement



135
136
137
138
139
140
141
142
143
 
# File 'lib/rubocop/ast/node/if_node.rb', line 135

def node_parts
  if unless?
    condition, false_branch, true_branch = *self
  else
    condition, true_branch, false_branch = *self
  end

  [condition, true_branch, false_branch]
end

#ternary? ⇒ Boolean

Checks whether the ‘if` node is a ternary operator.

Returns:

  • (Boolean) —

    whether the ‘if` node is a ternary operator



49
50
51
 
# File 'lib/rubocop/ast/node/if_node.rb', line 49

def ternary?
  loc.respond_to?(:question)
end

#unless? ⇒ Boolean

Checks whether this node is an ‘unless` statement. (This is not true of ternary operators and `if` statements.)

Returns:

  • (Boolean) —

    whether the node is an ‘unless` statement



24
25
26
 
# File 'lib/rubocop/ast/node/if_node.rb', line 24

def unless?
  keyword == 'unless'
end