AdminMailer tests 'resource.is_a?(User)' at least 4 times Open
return t('titles.developer', brand: t('titles.brand')) if resource.is_a?(User)
end
def sign_in_url_for(resource)
if resource.is_a?(Admin)
- Read upRead up
- Exclude checks
Repeated Conditional
is a special case of Simulated Polymorphism
. Basically it means you are checking the same value throughout a single class and take decisions based on this.
Example
Given
class RepeatedConditionals
attr_accessor :switch
def repeat_1
puts "Repeat 1!" if switch
end
def repeat_2
puts "Repeat 2!" if switch
end
def repeat_3
puts "Repeat 3!" if switch
end
end
Reek would emit the following warning:
test.rb -- 4 warnings:
[5, 9, 13]:RepeatedConditionals tests switch at least 3 times (RepeatedConditional)
If you get this warning then you are probably not using the right abstraction or even more probable, missing an additional abstraction.
AdminMailer tests 'resource.is_a?(Admin)' at least 4 times Open
return t('titles.admin', brand: t('titles.brand')) if resource.is_a?(Admin)
return t('titles.developer', brand: t('titles.brand')) if resource.is_a?(User)
end
def sign_in_url_for(resource)
- Read upRead up
- Exclude checks
Repeated Conditional
is a special case of Simulated Polymorphism
. Basically it means you are checking the same value throughout a single class and take decisions based on this.
Example
Given
class RepeatedConditionals
attr_accessor :switch
def repeat_1
puts "Repeat 1!" if switch
end
def repeat_2
puts "Repeat 2!" if switch
end
def repeat_3
puts "Repeat 3!" if switch
end
end
Reek would emit the following warning:
test.rb -- 4 warnings:
[5, 9, 13]:RepeatedConditionals tests switch at least 3 times (RepeatedConditional)
If you get this warning then you are probably not using the right abstraction or even more probable, missing an additional abstraction.
AdminMailer assumes too much for instance variable '@portal' Open
class AdminMailer < ApplicationMailer
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- Exclude checks
Classes should not assume that instance variables are set or present outside of the current class definition.
Good:
class Foo
def initialize
@bar = :foo
end
def foo?
@bar == :foo
end
end
Good as well:
class Foo
def foo?
bar == :foo
end
def bar
@bar ||= :foo
end
end
Bad:
class Foo
def go_foo!
@bar = :foo
end
def foo?
@bar == :foo
end
end
Example
Running Reek on:
class Dummy
def test
@ivar
end
end
would report:
[1]:InstanceVariableAssumption: Dummy assumes too much for instance variable @ivar
Note that this example would trigger this smell warning as well:
class Parent
def initialize(omg)
@omg = omg
end
end
class Child < Parent
def foo
@omg
end
end
The way to address the smell warning is that you should create an attr_reader
to use @omg
in the subclass and not access @omg
directly like this:
class Parent
attr_reader :omg
def initialize(omg)
@omg = omg
end
end
class Child < Parent
def foo
omg
end
end
Directly accessing instance variables is considered a smell because it breaks encapsulation and makes it harder to reason about code.
If you don't want to expose those methods as public API just make them private like this:
class Parent
def initialize(omg)
@omg = omg
end
private
attr_reader :omg
end
class Child < Parent
def foo
omg
end
end
Current Support in Reek
An instance variable must:
- be set in the constructor
- or be accessed through a method with lazy initialization / memoization.
If not, Instance Variable Assumption will be reported.
AdminMailer#portal_for calls 't('titles.brand')' 2 times Open
return t('titles.admin', brand: t('titles.brand')) if resource.is_a?(Admin)
return t('titles.developer', brand: t('titles.brand')) if resource.is_a?(User)
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- Exclude checks
Duplication occurs when two fragments of code look nearly identical, or when two fragments of code have nearly identical effects at some conceptual level.
Reek implements a check for Duplicate Method Call.
Example
Here's a very much simplified and contrived example. The following method will report a warning:
def double_thing()
@other.thing + @other.thing
end
One quick approach to silence Reek would be to refactor the code thus:
def double_thing()
thing = @other.thing
thing + thing
end
A slightly different approach would be to replace all calls of double_thing
by calls to @other.double_thing
:
class Other
def double_thing()
thing + thing
end
end
The approach you take will depend on balancing other factors in your code.
Similar blocks of code found in 2 locations. Consider refactoring. Open
def sign_in_url_for(resource)
if resource.is_a?(Admin)
return new_admin_session_url(subdomain: ENV.fetch('ADMIN_SUBDOMAIN',
nil))
end
- Read upRead up
Duplicated Code
Duplicated code can lead to software that is hard to understand and difficult to change. The Don't Repeat Yourself (DRY) principle states:
Every piece of knowledge must have a single, unambiguous, authoritative representation within a system.
When you violate DRY, bugs and maintenance problems are sure to follow. Duplicated code has a tendency to both continue to replicate and also to diverge (leaving bugs as two similar implementations differ in subtle ways).
Tuning
This issue has a mass of 26.
We set useful threshold defaults for the languages we support but you may want to adjust these settings based on your project guidelines.
The threshold configuration represents the minimum mass a code block must have to be analyzed for duplication. The lower the threshold, the more fine-grained the comparison.
If the engine is too easily reporting duplication, try raising the threshold. If you suspect that the engine isn't catching enough duplication, try lowering the threshold. The best setting tends to differ from language to language.
See codeclimate-duplication
's documentation for more information about tuning the mass threshold in your .codeclimate.yml
.
Refactorings
- Extract Method
- Extract Class
- Form Template Method
- Introduce Null Object
- Pull Up Method
- Pull Up Field
- Substitute Algorithm
Further Reading
- Don't Repeat Yourself on the C2 Wiki
- Duplicated Code on SourceMaking
- Refactoring: Improving the Design of Existing Code by Martin Fowler. Duplicated Code, p76
Similar blocks of code found in 2 locations. Consider refactoring. Open
def password_url_for(resource)
if resource.is_a?(Admin)
return new_admin_password_url(subdomain: ENV.fetch('ADMIN_SUBDOMAIN',
nil))
end
- Read upRead up
Duplicated Code
Duplicated code can lead to software that is hard to understand and difficult to change. The Don't Repeat Yourself (DRY) principle states:
Every piece of knowledge must have a single, unambiguous, authoritative representation within a system.
When you violate DRY, bugs and maintenance problems are sure to follow. Duplicated code has a tendency to both continue to replicate and also to diverge (leaving bugs as two similar implementations differ in subtle ways).
Tuning
This issue has a mass of 26.
We set useful threshold defaults for the languages we support but you may want to adjust these settings based on your project guidelines.
The threshold configuration represents the minimum mass a code block must have to be analyzed for duplication. The lower the threshold, the more fine-grained the comparison.
If the engine is too easily reporting duplication, try raising the threshold. If you suspect that the engine isn't catching enough duplication, try lowering the threshold. The best setting tends to differ from language to language.
See codeclimate-duplication
's documentation for more information about tuning the mass threshold in your .codeclimate.yml
.
Refactorings
- Extract Method
- Extract Class
- Form Template Method
- Introduce Null Object
- Pull Up Method
- Pull Up Field
- Substitute Algorithm
Further Reading
- Don't Repeat Yourself on the C2 Wiki
- Duplicated Code on SourceMaking
- Refactoring: Improving the Design of Existing Code by Martin Fowler. Duplicated Code, p76