Class: Hone::Patterns::HashKeysInclude

Inherits:
Base
  • Object
show all
Defined in:
lib/hone/patterns/hash_keys_include.rb

Overview

Pattern: hash.keys.include?(key) -> hash.key?(key)

keys.include? creates an array of all keys then searches it (O(n)). key? does a direct hash lookup (O(1)).

Instance Attribute Summary

Attributes inherited from Base

#findings

Instance Method Summary collapse

Methods inherited from Base

#add_finding, inherited, #initialize, scan_file

Constructor Details

This class inherits a constructor from Hone::Patterns::Base

Instance Method Details

#visit_call_node(node) ⇒ Object 



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# File 'lib/hone/patterns/hash_keys_include.rb', line 13

def visit_call_node(node)
  super

  # Look for: .include?(x) where receiver is .keys
  return unless node.name == :include? && node.arguments&.arguments&.size == 1

  receiver = node.receiver
  return unless receiver.is_a?(Prism::CallNode) && receiver.name == :keys

  add_finding(
    node,
    message: "Use `.key?(k)` instead of `.keys.include?(k)` for O(1) lookup without array allocation",
    speedup: "O(n) to O(1), avoids allocating array of all keys"
  )
end