class Ameba::Rule::Performance::SizeAfterFilter

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

Defined in:

ameba/rule/performance/size_after_filter.cr

Constant Summary

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

Constructors

Class Method Summary

Instance Method Summary

Instance methods inherited from class Ameba::Rule::Performance::Base

catch(source : Source) catch

Constructor methods inherited from class Ameba::Rule::Performance::Base

new(ctx : YAML::ParseContext, node : YAML::Nodes::Node)
new(config = nil) new

Class methods inherited from class Ameba::Rule::Performance::Base

parsed_doc : String | Nil parsed_doc

Instance methods inherited from class Ameba::Rule::Base

==(other) ==, catch(source : Source) catch, excluded?(source) excluded?, group group, hash hash, name name, special? special?, test(source : Source, node : Crystal::ASTNode, *opts)
test(source : Source) test

Class methods inherited from class Ameba::Rule::Base

default_severity : Ameba::Severity default_severity

Constructor Detail

def self.new(ctx : YAML::ParseContext, node : YAML::Nodes::Node) #

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

def self.new(config = nil) #

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

[View source]

Class Method Detail

def self.parsed_doc : String | Nil #

Returns documentation for this rule, if there is any.

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

def description : String #

def description=(description : String) #

def enabled=(enabled : Bool) #

def enabled? : Bool #

def excluded : Array(String) | Nil #

def excluded=(excluded : Array(String) | Nil) #

def filter_names : Array(String) #

def filter_names=(filter_names : Array(String)) #

def severity : Ameba::Severity #

def severity=(severity : Ameba::Severity) #

def test(source, node : Crystal::Call) #

[View source]
def test(source) #

[View source]