class Ameba::Rule::Performance::SizeAfterFilter

• Ameba::Rule::Performance::SizeAfterFilter
• Ameba::Rule::Performance::Base
• Ameba::Rule::Base
• Reference
• Object

Overview

This rule is used to identify usage of size calls that follow filter.

For example, this is considered invalid:

[1, 2, 3].select { |e| e > 2 }.size
[1, 2, 3].reject { |e| e < 2 }.size
[1, 2, 3].select(&.< 2).size
[0, 1, 2].select(&.zero?).size
[0, 1, 2].reject(&.zero?).size

And it should be written as this:

[1, 2, 3].count { |e| e > 2 }
[1, 2, 3].count { |e| e >= 2 }
[1, 2, 3].count(&.< 2)
[0, 1, 2].count(&.zero?)
[0, 1, 2].count(&.!= 0)

YAML configuration example:

Performance/SizeAfterFilter:
  Enabled: true
  FilterNames:
    - select
    - reject

Included Modules

• Ameba::AST::Util
• YAML::Serializable
• YAML::Serializable::Strict

Defined in:

Constant Summary

MSG = "Use `count {...}` instead of `%s {...}.size`."

Constructors

• .new(ctx : YAML::ParseContext, node : YAML::Nodes::Node)

  This rule is used to identify usage of size calls that follow filter.

• .new(config = nil)

  This rule is used to identify usage of size calls that follow filter.

Class Method Summary

• .parsed_doc : String | Nil

  Returns documentation for this rule, if there is any.

Instance Method Summary

• #description : String
• #description=(description : String)
• #enabled=(enabled : Bool)
• #enabled? : Bool
• #excluded : Array(String) | Nil
• #excluded=(excluded : Array(String) | Nil)
• #filter_names : Array(String)
• #filter_names=(filter_names : Array(String))
• #severity : Ameba::Severity
• #severity=(severity : Ameba::Severity)
• #test(source, node : Crystal::Call)
• #test(source)

Constructor Detail

[1, 2, 3].select { |e| e > 2 }.size
[1, 2, 3].reject { |e| e < 2 }.size
[1, 2, 3].select(&.< 2).size
[0, 1, 2].select(&.zero?).size
[0, 1, 2].reject(&.zero?).size

[1, 2, 3].count { |e| e > 2 }
[1, 2, 3].count { |e| e >= 2 }
[1, 2, 3].count(&.< 2)
[0, 1, 2].count(&.zero?)
[0, 1, 2].count(&.!= 0)

Performance/SizeAfterFilter:
  Enabled: true
  FilterNames:
    - select
    - reject

[1, 2, 3].select { |e| e > 2 }.size
[1, 2, 3].reject { |e| e < 2 }.size
[1, 2, 3].select(&.< 2).size
[0, 1, 2].select(&.zero?).size
[0, 1, 2].reject(&.zero?).size

[1, 2, 3].count { |e| e > 2 }
[1, 2, 3].count { |e| e >= 2 }
[1, 2, 3].count(&.< 2)
[0, 1, 2].count(&.zero?)
[0, 1, 2].count(&.!= 0)

Performance/SizeAfterFilter:
  Enabled: true
  FilterNames:
    - select
    - reject

Class Method Detail

module Ameba
  # This is a test rule.
  # Does nothing.
  class MyRule < Ameba::Rule::Base
    def test(source)
    end
  end
end

MyRule.parsed_doc # => "This is a test rule.\nDoes nothing."

Instance Method Detail