Performance-CompareWithBlock.md

Pattern: Slow compare with block

Issue: -

Description

This rule identifies places where sort { |a, b| a.foo <=> b.foo } can be replaced by sort_by(&:foo). This rule also checks max and min methods.

Examples

# bad
array.sort { |a, b| a.foo <=> b.foo }
array.max { |a, b| a.foo <=> b.foo }
array.min { |a, b| a.foo <=> b.foo }
array.sort { |a, b| a[:foo] <=> b[:foo] }

# good
array.sort_by(&:foo)
array.sort_by { |v| v.foo }
array.sort_by do |var|
  var.foo
end
array.max_by(&:foo)
array.min_by(&:foo)
array.sort_by { |a| a[:foo] }

Further Reading

• RuboCop - Performance/CompareWithBlock