Question has at least 16 methods Open
class Question
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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)
Question#response_pairs has approx 9 statements Open
def response_pairs(responses)
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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.)
Question#valid_choice_value? is controlled by argument 'value' Open
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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".
Method response_pairs
has a Cognitive Complexity of 8 (exceeds 5 allowed). Consider refactoring. Open
def response_pairs(responses)
responses = [responses] unless responses.is_a?(Array)
responses = responses.reject(&:blank?)
case
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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
Question#response_pairs calls 'responses.length > 1' 2 times Open
fail SurveyError, 'Multiple responses for an exclusive question' if responses.length > 1
[[key, responses.first]]
when exclusive_combo?
if responses.length > 1
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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.
Question#response_pairs calls 'responses.length' 2 times Open
fail SurveyError, 'Multiple responses for an exclusive question' if responses.length > 1
[[key, responses.first]]
when exclusive_combo?
if responses.length > 1
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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.
Question#response_pairs calls 'responses.first' 3 times Open
[[key, responses.first]]
when exclusive?
fail SurveyError, 'Multiple responses for an exclusive question' if responses.length > 1
[[key, responses.first]]
when exclusive_combo?
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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.
Question#choices has the variable name 'v' Open
@choices ||= @hash['values'].map {|v| Choice.new(self, v) }
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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.
Question#response_pairs has the variable name 'r' Open
responses.map do |r|
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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.
Question#valid_choice_value? has the variable name 'c' Open
choices.detect {|c| c.value == value } != nil ||
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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.
Missing magic comment # frozen_string_literal: true
. Open
# This is not backed to the database, but just initialized by loading the form
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This cop is designed to help upgrade to Ruby 3.0. It will add the
comment # frozen_string_literal: true
to the top of files to
enable frozen string literals. Frozen string literals may be default
in Ruby 3.0. The comment will be added below a shebang and encoding
comment. The frozen string literal comment is only valid in Ruby 2.3+.
Example: EnforcedStyle: when_needed (default)
# The `when_needed` style will add the frozen string literal comment
# to files only when the `TargetRubyVersion` is set to 2.3+.
# bad
module Foo
# ...
end
# good
# frozen_string_literal: true
module Foo
# ...
end
Example: EnforcedStyle: always
# The `always` style will always add the frozen string literal comment
# to a file, regardless of the Ruby version or if `freeze` or `<<` are
# called on a string literal.
# bad
module Bar
# ...
end
# good
# frozen_string_literal: true
module Bar
# ...
end
Example: EnforcedStyle: never
# The `never` will enforce that the frozen string literal comment does
# not exist in a file.
# bad
# frozen_string_literal: true
module Baz
# ...
end
# good
module Baz
# ...
end
Prefer !expression.nil?
over expression != nil
. Open
choices.detect {|c| c.value == value } != nil ||
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This cop checks for non-nil checks, which are usually redundant.
Example:
# bad
if x != nil
end
# good (when not allowing semantic changes)
# bad (when allowing semantic changes)
if !x.nil?
end
# good (when allowing semantic changes)
if x
end
Non-nil checks are allowed if they are the final nodes of predicate.
# good
def signed_in?
!current_user.nil?
end
Always use raise
to signal exceptions. Open
fail SurveyError, 'Multiple responses for an exclusive question' if responses.length > 1
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This cop checks for uses of fail
and raise
.
Example: EnforcedStyle: only_raise (default)
# The `only_raise` style enforces the sole use of `raise`.
# bad
begin
fail
rescue Exception
# handle it
end
def watch_out
fail
rescue Exception
# handle it
end
Kernel.fail
# good
begin
raise
rescue Exception
# handle it
end
def watch_out
raise
rescue Exception
# handle it
end
Kernel.raise
Example: EnforcedStyle: only_fail
# The `only_fail` style enforces the sole use of `fail`.
# bad
begin
raise
rescue Exception
# handle it
end
def watch_out
raise
rescue Exception
# handle it
end
Kernel.raise
# good
begin
fail
rescue Exception
# handle it
end
def watch_out
fail
rescue Exception
# handle it
end
Kernel.fail
Example: EnforcedStyle: semantic
# The `semantic` style enforces the use of `fail` to signal an
# exception, then will use `raise` to trigger an offense after
# it has been rescued.
# bad
begin
raise
rescue Exception
# handle it
end
def watch_out
# Error thrown
rescue Exception
fail
end
Kernel.fail
Kernel.raise
# good
begin
fail
rescue Exception
# handle it
end
def watch_out
fail
rescue Exception
raise 'Preferably with descriptive message'
end
explicit_receiver.fail
explicit_receiver.raise
Do not use empty case
condition, instead use an if
expression. Open
case
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This cop checks for case statements with an empty condition.
Example:
# bad:
case
when x == 0
puts 'x is 0'
when y == 0
puts 'y is 0'
else
puts 'neither is 0'
end
# good:
if x == 0
puts 'x is 0'
elsif y == 0
puts 'y is 0'
else
puts 'neither is 0'
end
# good: (the case condition node is not empty)
case n
when 0
puts 'zero'
when 1
puts 'one'
else
puts 'more'
end