Method has too many lines. [12/10] Open
def parse_options
options = {}
OptionParser.new do |opts|
opts.on('-d', '--debug',
'Show stack traces when an error occurs.') do |opt|
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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.
LolDba::CLI#select_action refers to 'arg' more than self (maybe move it to another class?) Open
if arg =~ /db:find_indexes/
success = LolDba::IndexFinder.run
exit(1) if success
elsif arg !~ /\[/
LolDba::SqlGenerator.run('all')
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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.
LolDba::CLI#parse_options contains iterators nested 2 deep Open
opts.on('-d', '--debug',
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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)
LolDba::CLI#start has approx 7 statements Open
def start(arg)
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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.)
LolDba::CLI#parse_options has approx 8 statements Open
def parse_options
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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.)
LolDba::CLI has no descriptive comment Open
class CLI
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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
Parenthesize the param exception.backtrace.map { |trace| " from #{trace}" }
to make sure that the block will be associated with the exception.backtrace.map
method call. Open
warn exception.backtrace.map { |trace| " from #{trace}" }
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This cop checks for ambiguous block association with method when param passed without parentheses.
Example:
# bad
some_method a { |val| puts val }
Example:
# good
# With parentheses, there's no ambiguity.
some_method(a) { |val| puts val }
# good
# Operator methods require no disambiguation
foo == bar { |b| b.baz }
# good
# Lambda arguments require no disambiguation
foo = ->(bar) { bar.baz }
Avoid rescuing the Exception
class. Perhaps you meant to rescue StandardError
? Open
rescue Exception => exception
if @options[:debug]
warn "Failed: #{exception.class}: #{exception.message}"
warn exception.backtrace.map { |trace| " from #{trace}" }
end
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This cop checks for rescue blocks targeting the Exception class.
Example:
# bad
begin
do_something
rescue Exception
handle_exception
end
Example:
# good
begin
do_something
rescue ArgumentError
handle_exception
end
Prefer $ERROR_INFO
from the stdlib 'English' module (don't forget to require it) over $!
. Open
raise $!
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Missing top-level class documentation comment. Open
class CLI
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This cop checks for missing top-level documentation of classes and modules. Classes with no body are exempt from the check and so are namespace modules - modules that have nothing in their bodies except classes, other modules, or constant definitions.
The documentation requirement is annulled if the class or module has a "#:nodoc:" comment next to it. Likewise, "#:nodoc: all" does the same for all its children.
Example:
# bad
class Person
# ...
end
# good
# Description/Explanation of Person class
class Person
# ...
end