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::ASSIGNMENTS, Node::BASIC_CONDITIONALS, Node::BASIC_LITERALS, Node::COMPARISON_OPERATORS, Node::COMPOSITE_LITERALS, Node::CONDITIONALS, Node::EQUALS_ASSIGNMENTS, Node::FALSEY_LITERALS, Node::IMMUTABLE_LITERALS, Node::KEYWORDS, Node::LITERALS, Node::MUTABLE_LITERALS, Node::OPERATOR_KEYWORDS, Node::REFERENCES, Node::SHORTHAND_ASSIGNMENTS, 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?, #assignment?, #basic_conditional?, #basic_literal?, #boolean_type?, #call_type?, #chained?, #child_nodes, #complete!, #complete?, #conditional?, #const_name, #defined_module, #defined_module_name, #descendants, #each_ancestor, #each_child_node, #each_descendant, #each_node, #empty_source?, #equals_asgn?, #falsey_literal?, #first_line, #guard_clause?, #immutable_literal?, #initialize, #keyword?, #last_line, #line_count, #literal?, #multiline?, #mutable_literal?, #nonempty_line_count, #numeric_type?, #operator_keyword?, #parent, #parent_module_name, #parenthesized_call?, #pure?, #range_type?, #receiver, #reference?, #shorthand_asgn?, #sibling_index, #single_line?, #source, #source_length, #source_range, #special_keyword?, #truthy_literal?, #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

#branches ⇒ Array<Node>

Returns an array of all the branches in the conditional statement.



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# File 'lib/rubocop/ast/node/if_node.rb', line 148

def branches
  branches = [if_branch]

  return branches unless else_branch

  other_branches = if elsif_conditional?
                     else_branch.branches
                   else
                     [else_branch]
                   end
  branches.concat(other_branches)
end

#each_branch ⇒ self, Enumerator

Calls the given block for each branch node in the conditional statement. If no block is given, an Enumerator is returned.



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# File 'lib/rubocop/ast/node/if_node.rb', line 166

def each_branch
  return branches.to_enum(__method__) unless block_given?

  branches.each do |branch|
    yield branch
  end
end

#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.



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# 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.



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# 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.



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# 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.



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

def elsif_conditional?
  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.)



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# 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.



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# 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.



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# 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.



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# 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.



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# 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.



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# 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.



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# 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.



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# 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.)



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

def unless?
  keyword == 'unless'
end