Complex method TagLayout::WalkWellsByPools#walk_wells (53.5) Open
def walk_wells # rubocop:todo Metrics/CyclomaticComplexity
# Adjust each of the groups so that any wells that are in the same pool as those at the same position
# in the group to the left are moved to a non-clashing position. Effectively this makes the view of the
# plate slightly jagged.
group_size =
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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
Method walk_wells
has a Cognitive Complexity of 19 (exceeds 5 allowed). Consider refactoring. Open
def walk_wells # rubocop:todo Metrics/CyclomaticComplexity
# Adjust each of the groups so that any wells that are in the same pool as those at the same position
# in the group to the left are moved to a non-clashing position. Effectively this makes the view of the
# plate slightly jagged.
group_size =
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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
TagLayout::WalkWellsByPools#walk_wells contains iterators nested 2 deep Open
.map { |wells| wells.map { |well| [well, well.pool_id] } }
wells_in_groups.each_with_index do |current_group, group|
next if group == 0
prior_group = wells_in_groups[group - 1]
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A Nested Iterator
occurs when a block contains another block.
Example
Given
class Duck
class << self
def duck_names
%i!tick trick track!.each do |surname|
%i!duck!.each do |last_name|
puts "full name is #{surname} #{last_name}"
end
end
end
end
end
Reek would report the following warning:
test.rb -- 1 warning:
[5]:Duck#duck_names contains iterators nested 2 deep (NestedIterators)
TagLayout::WalkWellsByPools#walk_wells has approx 18 statements Open
def walk_wells # rubocop:todo Metrics/CyclomaticComplexity
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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.)
TagLayout::WalkWellsByPools#walk_wells calls 'plate.size' 2 times Open
direction.to_sym == :column ? Map::Coordinate.plate_length(plate.size) : Map::Coordinate.plate_width(plate.size)
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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.
TagLayout::WalkWellsByPools#walk_wells calls 'well_and_pool.last' 2 times Open
next unless prior_group[index].last == well_and_pool.last
current_group.push(well_and_pool) # Move the well to the end of the group
# rubocop:todo Layout/LineLength
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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.
TagLayout::WalkWellsByPools has no descriptive comment Open
class TagLayout::WalkWellsByPools < TagLayout::Walker
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Classes and modules are the units of reuse and release. It is therefore considered good practice to annotate every class and module with a brief comment outlining its responsibilities.
Example
Given
class Dummy
# Do things...
end
Reek would emit the following warning:
test.rb -- 1 warning:
[1]:Dummy has no descriptive comment (IrresponsibleModule)
Fixing this is simple - just an explaining comment:
# The Dummy class is responsible for ...
class Dummy
# Do things...
end
TagLayout::WalkWellsByPools#walk_wells performs a nil-check Open
wells_in_groups.each { |group| group.each_with_index { |(well, _), index| yield(well, index) unless well.nil? } }
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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)