Class Match
has 36 methods (exceeds 20 allowed). Consider refactoring. Wontfix
class Match < ApplicationRecord
belongs_to :team_home, polymorphic: true
belongs_to :team_away, polymorphic: true
belongs_to :event
has_many :game_results, dependent: :destroy
Complex method Match#calculate_points (33.8) Wontfix
def calculate_points
if !has_scores?
set_points(nil, nil)
elsif wins_home > wins_away
set_points(event.points_for_win, event.points_for_lose)
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Flog calculates the ABC score for methods. The ABC score is based on assignments, branches (method calls), and conditions.
You can read more about ABC metrics or the flog tool
Match#opponent_of is controlled by argument 'participant' Confirmed
return home if participant == away
return away if participant == home
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Control Parameter
is a special case of Control Couple
Example
A simple example would be the "quoted" parameter in the following method:
def write(quoted)
if quoted
write_quoted @value
else
write_unquoted @value
end
end
Fixing those problems is out of the scope of this document but an easy solution could be to remove the "write" method alltogether and to move the calls to "writequoted" / "writeunquoted" in the initial caller of "write".
Match#has_scores? refers to 'result' more than self (maybe move it to another class?) Wontfix
if result.score_home.present? && result.score_away.present?
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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.
Match#standing_string_of is controlled by argument 'team' Invalid
if loser == team
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Control Parameter
is a special case of Control Couple
Example
A simple example would be the "quoted" parameter in the following method:
def write(quoted)
if quoted
write_quoted @value
else
write_unquoted @value
end
end
Fixing those problems is out of the scope of this document but an easy solution could be to remove the "write" method alltogether and to move the calls to "writequoted" / "writeunquoted" in the initial caller of "write".
Match#select_results_by_score refers to 'current_result' more than self (maybe move it to another class?) Wontfix
game_results.select { |current_result| (current_result.score_home.nil? || current_result.score_away.nil?) ? false : current_result.score_home.send(score_comparison, current_result.score_away) }
- Read upRead up
- Exclude checks
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.
Match#update_with_point_recalculation has approx 6 statements Wontfix
def update_with_point_recalculation(attributes)
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A method with Too Many Statements
is any method that has a large number of lines.
Too Many Statements
warns about any method that has more than 5 statements. Reek's smell detector for Too Many Statements
counts +1 for every simple statement in a method and +1 for every statement within a control structure (if
, else
, case
, when
, for
, while
, until
, begin
, rescue
) but it doesn't count the control structure itself.
So the following method would score +6 in Reek's statement-counting algorithm:
def parse(arg, argv, &error)
if !(val = arg) and (argv.empty? or /\A-/ =~ (val = argv[0]))
return nil, block, nil # +1
end
opt = (val = parse_arg(val, &error))[1] # +2
val = conv_arg(*val) # +3
if opt and !arg
argv.shift # +4
else
val[0] = nil # +5
end
val # +6
end
(You might argue that the two assigments within the first @if@ should count as statements, and that perhaps the nested assignment should count as +2.)
Match has at least 36 methods Wontfix
class Match < ApplicationRecord
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Too Many Methods
is a special case of LargeClass
.
Example
Given this configuration
TooManyMethods:
max_methods: 3
and this code:
class TooManyMethods
def one; end
def two; end
def three; end
def four; end
end
Reek would emit the following warning:
test.rb -- 1 warning:
[1]:TooManyMethods has at least 4 methods (TooManyMethods)
Match declares the class variable '@@winner_strategy' Wontfix
@@winner_strategy = { "most_sets" => lambda { |match| (match.wins_home > match.wins_away ? match.team_home_recursive : match.team_away_recursive) if match.has_winner? } }
@@loser_strategy = { "most_sets" => lambda { |match| (match.wins_home < match.wins_away ? match.team_home_recursive : match.team_away_recursive) if match.has_winner? } }
def depth
event.finale_gameday - gameday_number
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Class variables form part of the global runtime state, and as such make it easy for one part of the system to accidentally or inadvertently depend on another part of the system. So the system becomes more prone to problems where changing something over here breaks something over there. In particular, class variables can make it hard to set up tests (because the context of the test includes all global state).
For a detailed explanation, check out this article
Example
Given
class Dummy
@@class_variable = :whatever
end
Reek would emit the following warning:
reek test.rb
test.rb -- 1 warning:
[2]:Dummy declares the class variable @@class_variable (ClassVariable)
Getting rid of the smell
You can use class-instance variable to mitigate the problem (as also suggested in the linked article above):
class Dummy
@class_variable = :whatever
end
Match declares the class variable '@@loser_strategy' Wontfix
@@loser_strategy = { "most_sets" => lambda { |match| (match.wins_home < match.wins_away ? match.team_home_recursive : match.team_away_recursive) if match.has_winner? } }
def depth
event.finale_gameday - gameday_number
end
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Class variables form part of the global runtime state, and as such make it easy for one part of the system to accidentally or inadvertently depend on another part of the system. So the system becomes more prone to problems where changing something over here breaks something over there. In particular, class variables can make it hard to set up tests (because the context of the test includes all global state).
For a detailed explanation, check out this article
Example
Given
class Dummy
@@class_variable = :whatever
end
Reek would emit the following warning:
reek test.rb
test.rb -- 1 warning:
[2]:Dummy declares the class variable @@class_variable (ClassVariable)
Getting rid of the smell
You can use class-instance variable to mitigate the problem (as also suggested in the linked article above):
class Dummy
@class_variable = :whatever
end
Match#calculate_points calls 'event.points_for_lose' 2 times Wontfix
set_points(event.points_for_win, event.points_for_lose)
elsif wins_home < wins_away
set_points(event.points_for_lose, event.points_for_win)
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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.
Match#calculate_points calls 'event.points_for_win' 2 times Wontfix
set_points(event.points_for_win, event.points_for_lose)
elsif wins_home < wins_away
set_points(event.points_for_lose, event.points_for_win)
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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.
Match#calculate_points calls 'event.points_for_draw' 2 times Wontfix
set_points(event.points_for_draw, event.points_for_draw)
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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.
Match#select_results_by_score calls 'current_result.score_home' 2 times Wontfix
game_results.select { |current_result| (current_result.score_home.nil? || current_result.score_away.nil?) ? false : current_result.score_home.send(score_comparison, current_result.score_away) }
- 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.
Match declares the class variable '@@has_winner_strategy' Wontfix
@@has_winner_strategy = { "most_sets" => lambda { |match| match.wins_home != match.wins_away } }
@@winner_strategy = { "most_sets" => lambda { |match| (match.wins_home > match.wins_away ? match.team_home_recursive : match.team_away_recursive) if match.has_winner? } }
@@loser_strategy = { "most_sets" => lambda { |match| (match.wins_home < match.wins_away ? match.team_home_recursive : match.team_away_recursive) if match.has_winner? } }
def depth
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- Exclude checks
Class variables form part of the global runtime state, and as such make it easy for one part of the system to accidentally or inadvertently depend on another part of the system. So the system becomes more prone to problems where changing something over here breaks something over there. In particular, class variables can make it hard to set up tests (because the context of the test includes all global state).
For a detailed explanation, check out this article
Example
Given
class Dummy
@@class_variable = :whatever
end
Reek would emit the following warning:
reek test.rb
test.rb -- 1 warning:
[2]:Dummy declares the class variable @@class_variable (ClassVariable)
Getting rid of the smell
You can use class-instance variable to mitigate the problem (as also suggested in the linked article above):
class Dummy
@class_variable = :whatever
end
Match#select_results_by_score calls 'current_result.score_away' 2 times Wontfix
game_results.select { |current_result| (current_result.score_home.nil? || current_result.score_away.nil?) ? false : current_result.score_home.send(score_comparison, current_result.score_away) }
- 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.
Match#select_results_by_score performs a nil-check Wontfix
game_results.select { |current_result| (current_result.score_home.nil? || current_result.score_away.nil?) ? false : current_result.score_home.send(score_comparison, current_result.score_away) }
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- Exclude checks
A NilCheck
is a type check. Failures of NilCheck
violate the "tell, don't ask" principle.
Additionally, type checks often mask bigger problems in your source code like not using OOP and / or polymorphism when you should.
Example
Given
class Klass
def nil_checker(argument)
if argument.nil?
puts "argument isn't nil!"
end
end
end
Reek would emit the following warning:
test.rb -- 1 warning:
[3]:Klass#nil_checker performs a nil-check. (NilCheck)