Finance::BillingStrategy::Results#successful? refers to 'status' more than self (maybe move it to another class?) Open
(status[:success] || status[:skip]) && status[:errors].empty?
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Feature Envy occurs when a code fragment references another object more often than it references itself, or when several clients do the same series of manipulations on a particular type of object.
Feature Envy reduces the code's ability to communicate intent: code that "belongs" on one class but which is located in another can be hard to find, and may upset the "System of Names" in the host class.
Feature Envy also affects the design's flexibility: A code fragment that is in the wrong class creates couplings that may not be natural within the application's domain, and creates a loss of cohesion in the unwilling host class.
Feature Envy often arises because it must manipulate other objects (usually its arguments) to get them into a useful form, and one force preventing them (the arguments) doing this themselves is that the common knowledge lives outside the arguments, or the arguments are of too basic a type to justify extending that type. Therefore there must be something which 'knows' about the contents or purposes of the arguments. That thing would have to be more than just a basic type, because the basic types are either containers which don't know about their contents, or they are single objects which can't capture their relationship with their fellows of the same type. So, this thing with the extra knowledge should be reified into a class, and the utility method will most likely belong there.
Example
Running Reek on:
class Warehouse
def sale_price(item)
(item.price - item.rebate) * @vat
end
end
would report:
Warehouse#total_price refers to item more than self (FeatureEnvy)
since this:
(item.price - item.rebate)
belongs to the Item class, not the Warehouse.
Finance::BillingStrategy::Results tests 'Rails.env.test?' at least 6 times Open
raise if Rails.env.test?
end
def success(billing_strategy)
@providers[billing_strategy.provider.id][:success] = true
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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.
Method providers_failed_count
has a Cognitive Complexity of 7 (exceeds 5 allowed). Consider refactoring. Open
def providers_failed_count
@providers.inject(0) do |sum, provider|
id, status = provider
status[:success] ? sum : sum + 1
end
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Cognitive Complexity
Cognitive Complexity is a measure of how difficult a unit of code is to intuitively understand. Unlike Cyclomatic Complexity, which determines how difficult your code will be to test, Cognitive Complexity tells you how difficult your code will be to read and comprehend.
A method's cognitive complexity is based on a few simple rules:
- Code is not considered more complex when it uses shorthand that the language provides for collapsing multiple statements into one
- Code is considered more complex for each "break in the linear flow of the code"
- Code is considered more complex when "flow breaking structures are nested"
Further reading
Finance::BillingStrategy::Results#success calls '@providers[billing_strategy.provider.id]' 2 times Open
@providers[billing_strategy.provider.id][:success] = true
@providers[billing_strategy.provider.id][:errors] = billing_strategy.failed_buyers
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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.
Finance::BillingStrategy::Results#success calls 'billing_strategy.provider' 2 times Open
@providers[billing_strategy.provider.id][:success] = true
@providers[billing_strategy.provider.id][:errors] = billing_strategy.failed_buyers
- Read upRead up
- 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.
Finance::BillingStrategy::Results#success calls 'billing_strategy.provider.id' 2 times Open
@providers[billing_strategy.provider.id][:success] = true
@providers[billing_strategy.provider.id][:errors] = billing_strategy.failed_buyers
- Read upRead up
- 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.
Finance::BillingStrategy::Results#skipped has the variable name 'v' Open
@providers.select { |k,v| v[:skip] }
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An Uncommunicative Variable Name
is a variable name that doesn't communicate its intent well enough.
Poor names make it hard for the reader to build a mental picture of what's going on in the code. They can also be mis-interpreted; and they hurt the flow of reading, because the reader must slow down to interpret the names.
Finance::BillingStrategy::Results#with_errors has the variable name 'k' Open
@providers.select { |k,v| v[:errors].present? }
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An Uncommunicative Variable Name
is a variable name that doesn't communicate its intent well enough.
Poor names make it hard for the reader to build a mental picture of what's going on in the code. They can also be mis-interpreted; and they hurt the flow of reading, because the reader must slow down to interpret the names.
Finance::BillingStrategy::Results#with_errors has the variable name 'v' Open
@providers.select { |k,v| v[:errors].present? }
- Read upRead up
- Exclude checks
An Uncommunicative Variable Name
is a variable name that doesn't communicate its intent well enough.
Poor names make it hard for the reader to build a mental picture of what's going on in the code. They can also be mis-interpreted; and they hurt the flow of reading, because the reader must slow down to interpret the names.
Finance::BillingStrategy::Results#skipped has the variable name 'k' Open
@providers.select { |k,v| v[:skip] }
- Read upRead up
- Exclude checks
An Uncommunicative Variable Name
is a variable name that doesn't communicate its intent well enough.
Poor names make it hard for the reader to build a mental picture of what's going on in the code. They can also be mis-interpreted; and they hurt the flow of reading, because the reader must slow down to interpret the names.