Class: RuboCop::Cop::InternalAffairs::NodePatternGroups::ASTProcessor

Inherits:
Object
  • Object
show all
Includes:
AST::Processor::Mixin
Defined in:
lib/rubocop/cop/internal_affairs/node_pattern_groups/ast_processor.rb

Overview

AST Processor for NodePattern ASTs, for use with ‘InternalAffairs/NodePatternGroups`.

Looks for sequences and subsequences where the first item is a ‘node_type` node, and converts them to `node_sequence` nodes (not a true `Rubocop::AST::NodePattern` node type).

The resulting AST will be walked by ‘InternalAffairs::NodePatternGroups::ASTWalker` in order to find node types in a `union` node that can be rewritten as a node group.

NOTE: The ‘on_*` methods in this class relate not to the normal node types but rather to the Node Pattern node types. Not every node type is handled.

Instance Method Summary collapse

Instance Method Details

#handler_missing(node) ⇒ Object 



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# File 'lib/rubocop/cop/internal_affairs/node_pattern_groups/ast_processor.rb', line 22

def handler_missing(node)
  node.updated(nil, process_children(node))
end

#on_sequence(node) ⇒ Object Also known as: on_subsequence

Look for ‘sequence` and `subsequence` nodes that contain a `node_type` node as their first child. These are rewritten as `node_sequence` nodes so that it is possible to compare nodes while looking for replacement candidates for node groups. This is necessary so that extended patterns can be matched and replaced. ie. `_ :foo …) (csend _ :foo …)` can become `(call _ :foo …)`



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# File 'lib/rubocop/cop/internal_affairs/node_pattern_groups/ast_processor.rb', line 31

def on_sequence(node)
  first_child = node.child

  if first_child.type == :node_type
    children = [first_child.child, *process_children(node, 1..)]

    # The `node_sequence` node contains the `node_type` symbol as its first child,
    # followed by all the other nodes contained in the `sequence` node.
    # The location is copied from the sequence, so that the entire sequence can
    # eventually be corrected in the cop.
    n(:node_sequence, children, location: node.location)
  else
    node.updated(nil, process_children(node))
  end
end