class Ameba::Rule::Lint::UnusedComparison

Overview

A rule that disallows unused comparisons.

For example, this is considered invalid:

a = obj.method do |x|
  x == 1 # => Comparison operation has no effect
  puts x
end

b = if a >= 0
      c < 1 # => Comparison operation has no effect
      "hello world"
    end

And these are considered valid:

a = obj.method do |x|
  x == 1
end

b = if a >= 0 &&
       c < 1
      "hello world"
    end

YAML configuration example:

Lint/UnusedComparison:
  Enabled: true

Included Modules

Defined in:

ameba/rule/lint/unused_comparison.cr

Constant Summary

COMPARISON_OPERATORS = ["==", "!=", "<", "<=", ">", ">=", "<=>"] of ::String
MSG = "Comparison operation is unused"

Constructors

Class Method Summary

Instance Method Summary

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

Macros inherited from class Ameba::Rule::Base

issue_for(*args, **kwargs, &block) issue_for

Macros inherited from module Ameba::Config::RuleConfig

properties(&block) properties

Constructor Detail

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

def self.new(config = nil) #

A rule that disallows unused comparisons.

For example, this is considered invalid:

a = obj.method do |x|
  x == 1 # => Comparison operation has no effect
  puts x
end

b = if a >= 0
      c < 1 # => Comparison operation has no effect
      "hello world"
    end

And these are considered valid:

a = obj.method do |x|
  x == 1
end

b = if a >= 0 &&
       c < 1
      "hello world"
    end

YAML configuration example:

Lint/UnusedComparison:
  Enabled: true

[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 severity : Ameba::Severity #

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

def since_version : SemanticVersion | Nil #

[View source]
def since_version=(since_version : String) #

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

[View source]
def test(source : Source) #
Description copied from class Ameba::Rule::Base

This method is designed to test the source passed in. If source has issues that are tested by this rule, it should add an issue.

By default it uses a node visitor to traverse all the nodes in the source.

NOTE Must be overridden for other type of rules.


[View source]