Method has too many lines. [17/10] Open
def initialize
@options = { connection:
{ hosts: ['localhost'],
port: 5672,
auth: { user: 'guest', password: 'guest' } },
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This cop checks if the length of a method exceeds some maximum value. Comment lines can optionally be ignored. The maximum allowed length is configurable.
Basquiat::Adapters::RabbitMq::Configuration assumes too much for instance variable '@strategy' Open
class Configuration
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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.
Basquiat::Adapters::RabbitMq::Configuration#initialize calls 'Basquiat.configuration' 2 times Open
name: Basquiat.configuration.queue_name,
durable: true,
options: {}
},
exchange: {
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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.
Basquiat::Adapters::RabbitMq::Configuration#merge_user_options has unused parameter 'kwargs' Open
def merge_user_options(*user_opts, **kwargs)
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Unused Parameter
refers to methods with parameters that are unused in scope of the method.
Having unused parameters in a method is code smell because leaving dead code in a method can never improve the method and it makes the code confusing to read.
Example
Given:
class Klass
def unused_parameters(x,y,z)
puts x,y # but not z
end
end
Reek would emit the following warning:
[2]:Klass#unused_parameters has unused parameter 'z' (UnusedParameters)
Unused method argument - kwargs
. If it's necessary, use _
or _kwargs
as an argument name to indicate that it won't be used. Open
def merge_user_options(*user_opts, **kwargs)
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This cop checks for unused method arguments.
Example:
# bad
def some_method(used, unused, _unused_but_allowed)
puts used
end
Example:
# good
def some_method(used, _unused, _unused_but_allowed)
puts used
end