Method has too many lines. [19/15] Open
def tree
all.each_with_object({}) do |db, data|
data[db.type] ||= []
use_parent = '#'
db.categories.each_with_index do |entry, index|
- Read upRead up
- Exclude checks
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.
You can set literals you want to fold with CountAsOne
.
Available are: 'array', 'hash', and 'heredoc'. Each literal
will be counted as one line regardless of its actual size.
NOTE: The ExcludedMethods
configuration is deprecated and only kept
for backwards compatibility. Please use IgnoredMethods
instead.
Example: CountAsOne: ['array', 'heredoc']
def m
array = [ # +1
1,
2
]
hash = { # +3
key: 'value'
}
<<~HEREDOC # +1
Heredoc
content.
HEREDOC
end # 5 points
Method tree
has a Cognitive Complexity of 11 (exceeds 5 allowed). Consider refactoring. Open
def tree
all.each_with_object({}) do |db, data|
data[db.type] ||= []
use_parent = '#'
db.categories.each_with_index do |entry, index|
- Read upRead up
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
Method retrieve
has a Cognitive Complexity of 9 (exceeds 5 allowed). Consider refactoring. Open
def retrieve(loci)
# Exit early if loci is nil.
return unless loci
# String -> Array
- Read upRead up
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
Assignment Branch Condition size for tree is too high. [<10, 30, 6> 32.19/17] Open
def tree
all.each_with_object({}) do |db, data|
data[db.type] ||= []
use_parent = '#'
db.categories.each_with_index do |entry, index|
- Read upRead up
- Exclude checks
This cop checks that the ABC size of methods is not higher than the configured maximum. The ABC size is based on assignments, branches (method calls), and conditions. See http://c2.com/cgi/wiki?AbcMetric and https://en.wikipedia.org/wiki/ABC_Software_Metric.
Interpreting ABC size:
- <= 17 satisfactory
- 18..30 unsatisfactory
- > 30 dangerous
You can have repeated "attributes" calls count as a single "branch".
For this purpose, attributes are any method with no argument; no attempt
is meant to distinguish actual attr_reader
from other methods.
Example: CountRepeatedAttributes: false (default is true)
# `model` and `current_user`, refenced 3 times each,
# are each counted as only 1 branch each if
# `CountRepeatedAttributes` is set to 'false'
def search
@posts = model.active.visible_by(current_user)
.search(params[:q])
@posts = model.some_process(@posts, current_user)
@posts = model.another_process(@posts, current_user)
render 'pages/search/page'
end
This cop also takes into account IgnoredMethods
(defaults to []
)
Use alias_method
instead of alias
. Open
alias path name
- Read upRead up
- Exclude checks
This cop enforces the use of either #alias
or #alias_method
depending on configuration.
It also flags uses of alias :symbol
rather than alias bareword
.
Example: EnforcedStyle: prefer_alias (default)
# bad
alias_method :bar, :foo
alias :bar :foo
# good
alias bar foo
Example: EnforcedStyle: preferaliasmethod
# bad
alias :bar :foo
alias bar foo
# good
alias_method :bar, :foo
Favor modifier if
usage when having a single-line body. Another good alternative is the usage of control flow &&
/||
. Open
if coords
- Read upRead up
- Exclude checks
Checks for if
and unless
statements that would fit on one line if
written as modifier if
/unless
. The cop also checks for modifier
if
/unless
lines that exceed the maximum line length.
The maximum line length is configured in the Layout/LineLength
cop. The tab size is configured in the IndentationWidth
of the
Layout/IndentationStyle
cop.
Example:
# bad
if condition
do_stuff(bar)
end
unless qux.empty?
Foo.do_something
end
do_something_with_a_long_name(arg) if long_condition_that_prevents_code_fit_on_single_line
# good
do_stuff(bar) if condition
Foo.do_something unless qux.empty?
if long_condition_that_prevents_code_fit_on_single_line
do_something_with_a_long_name(arg)
end
if short_condition # a long comment that makes it too long if it were just a single line
do_something
end
Favor modifier unless
usage when having a single-line body. Another good alternative is the usage of control flow &&
/||
. Open
unless seq
- Read upRead up
- Exclude checks
Checks for if
and unless
statements that would fit on one line if
written as modifier if
/unless
. The cop also checks for modifier
if
/unless
lines that exceed the maximum line length.
The maximum line length is configured in the Layout/LineLength
cop. The tab size is configured in the IndentationWidth
of the
Layout/IndentationStyle
cop.
Example:
# bad
if condition
do_stuff(bar)
end
unless qux.empty?
Foo.do_something
end
do_something_with_a_long_name(arg) if long_condition_that_prevents_code_fit_on_single_line
# good
do_stuff(bar) if condition
Foo.do_something unless qux.empty?
if long_condition_that_prevents_code_fit_on_single_line
do_something_with_a_long_name(arg)
end
if short_condition # a long comment that makes it too long if it were just a single line
do_something
end
Avoid using rescue
in its modifier form. Open
sys(cmd, path: config[:bin]) rescue false
- Read upRead up
- Exclude checks
This cop checks for uses of rescue in its modifier form.
The cop to check rescue
in its modifier form is added for following
reasons:
The syntax of modifier form
rescue
can be misleading because it might led us to believe thatrescue
handles the given exception but it actually rescue all exceptions to return the given rescue block. In this case, value returned by handle_error or SomeException.Modifier form
rescue
would rescue all the exceptions. It would silently skip all exception or errors and handle the error. Example: IfNoMethodError
is raised, modifier form rescue would handle the exception.
Example:
# bad
some_method rescue handle_error
# bad
some_method rescue SomeException
# good
begin
some_method
rescue
handle_error
end
# good
begin
some_method
rescue SomeException
handle_error
end
#to_json
requires an optional argument to be parsable via JSON.generate(obj). Open
def to_json
collection.values.to_json
end
- Read upRead up
- Exclude checks
This cop checks to make sure #to_json
includes an optional argument.
When overriding #to_json
, callers may invoke JSON
generation via JSON.generate(your_obj)
. Since JSON#generate
allows
for an optional argument, your method should too.
Example:
class Point
attr_reader :x, :y
# bad, incorrect arity
def to_json
JSON.generate([x, y])
end
# good, preserving args
def to_json(*args)
JSON.generate([x, y], *args)
end
# good, discarding args
def to_json(*_args)
JSON.generate([x, y])
end
end
Unnecessary spacing detected. Open
args[2].downcase! # type
- Read upRead up
- Exclude checks
This cop checks for extra/unnecessary whitespace.
Example:
# good if AllowForAlignment is true
name = "RuboCop"
# Some comment and an empty line
website += "/rubocop/rubocop" unless cond
puts "rubocop" if debug
# bad for any configuration
set_app("RuboCop")
website = "https://github.com/rubocop/rubocop"
# good only if AllowBeforeTrailingComments is true
object.method(arg) # this is a comment
# good even if AllowBeforeTrailingComments is false or not set
object.method(arg) # this is a comment
# good with either AllowBeforeTrailingComments or AllowForAlignment
object.method(arg) # this is a comment
another_object.method(arg) # this is another comment
some_object.method(arg) # this is some comment
Extra empty line detected at block body beginning. Open
extend Forwardable
- Read upRead up
- Exclude checks
This cop checks if empty lines around the bodies of blocks match the configuration.
Example: EnforcedStyle: empty_lines
# good
foo do |bar|
# ...
end
Example: EnforcedStyle: noemptylines (default)
# good
foo do |bar|
# ...
end
Add empty line after guard clause. Open
return if alias?
- Read upRead up
- Exclude checks
This cop enforces empty line after guard clause
Example:
# bad
def foo
return if need_return?
bar
end
# good
def foo
return if need_return?
bar
end
# good
def foo
return if something?
return if something_different?
bar
end
# also good
def foo
if something?
do_something
return if need_return?
end
end
Use the double pipe equals operator ||=
instead. Open
unless seq
seq = "# ERROR: #{locus} not found in any database"
end
- Read upRead up
- Exclude checks
This cop checks for potential usage of the ||=
operator.
Example:
# bad
name = name ? name : 'Bozhidar'
# bad
name = if name
name
else
'Bozhidar'
end
# bad
unless name
name = 'Bozhidar'
end
# bad
name = 'Bozhidar' unless name
# good - set name to 'Bozhidar', only if it's nil or false
name ||= 'Bozhidar'