Method flatter
has a Cognitive Complexity of 8 (exceeds 5 allowed). Consider refactoring. Open
def flatter
result = dup.clear
result.mass = mass
each_with_object(result) do |s, r|
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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
Use def with parentheses when there are parameters. Open
def post_filter *patterns
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- Exclude checks
This cops checks for parentheses around the arguments in method definitions. Both instance and class/singleton methods are checked.
Example: EnforcedStyle: require_parentheses (default)
# The `require_parentheses` style requires method definitions
# to always use parentheses
# bad
def bar num1, num2
num1 + num2
end
def foo descriptive_var_name,
another_descriptive_var_name,
last_descriptive_var_name
do_something
end
# good
def bar(num1, num2)
num1 + num2
end
def foo(descriptive_var_name,
another_descriptive_var_name,
last_descriptive_var_name)
do_something
end
Example: EnforcedStyle: requirenoparentheses
# The `require_no_parentheses` style requires method definitions
# to never use parentheses
# bad
def bar(num1, num2)
num1 + num2
end
def foo(descriptive_var_name,
another_descriptive_var_name,
last_descriptive_var_name)
do_something
end
# good
def bar num1, num2
num1 + num2
end
def foo descriptive_var_name,
another_descriptive_var_name,
last_descriptive_var_name
do_something
end
Example: EnforcedStyle: requirenoparenthesesexceptmultiline
# The `require_no_parentheses_except_multiline` style prefers no
# parantheses when method definition arguments fit on single line,
# but prefers parantheses when arguments span multiple lines.
# bad
def bar(num1, num2)
num1 + num2
end
def foo descriptive_var_name,
another_descriptive_var_name,
last_descriptive_var_name
do_something
end
# good
def bar num1, num2
num1 + num2
end
def foo(descriptive_var_name,
another_descriptive_var_name,
last_descriptive_var_name)
do_something
end
Redundant self
detected. Open
self.hashes.delete_if { |_, sexps|
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- Exclude checks
This cop checks for redundant uses of self
.
The usage of self
is only needed when:
Sending a message to same object with zero arguments in presence of a method name clash with an argument or a local variable.
Calling an attribute writer to prevent an local variable assignment.
Note, with using explicit self you can only send messages with public or protected scope, you cannot send private messages this way.
Note we allow uses of self
with operators because it would be awkward
otherwise.
Example:
# bad
def foo(bar)
self.baz
end
# good
def foo(bar)
self.bar # Resolves name clash with the argument.
end
def foo
bar = 1
self.bar # Resolves name clash with the local variable.
end
def foo
%w[x y z].select do |bar|
self.bar == bar # Resolves name clash with argument of the block.
end
end