Class: Hone::Patterns::HashEachKey

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

Overview

Pattern: hash.keys.each { } -> hash.each_key { }

keys.each creates an intermediate array of keys then iterates. each_key iterates keys directly without allocation.

Also detects hash.values.each { } -> hash.each_value { }

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_each_key.rb', line 15

def visit_call_node(node)
  super

  # Look for: .each { } where receiver is .keys or .values
  return unless node.name == :each && block_attached?(node)

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

  case receiver.name
  when :keys
    add_finding(
      node,
      message: "Use `.each_key { }` instead of `.keys.each { }` to avoid intermediate array",
      speedup: "Iterates keys directly without allocating array"
    )
  when :values
    add_finding(
      node,
      message: "Use `.each_value { }` instead of `.values.each { }` to avoid intermediate array",
      speedup: "Iterates values directly without allocating array"
    )
  end
end