Class: Hone::Patterns::ShuffleFirst

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

Overview

Pattern: array.shuffle.first -> array.sample

shuffle.first shuffles the entire array then takes the first element. sample directly selects a random element without creating intermediate array.

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/shuffle_first.rb', line 13

def visit_call_node(node)
  super

  # Look for: .first where receiver is .shuffle
  return unless node.name == :first && node.arguments.nil?

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

  add_finding(
    node,
    message: "Use `.sample` instead of `.shuffle.first` to avoid shuffling entire array",
    speedup: "Avoids O(n) shuffle and intermediate array allocation"
  )
end