Unprotected mass assignment Open
user = User.new(user_params)
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Mass assignment is a feature of Rails which allows an application to create a record from the values of a hash.
Example:
User.new(params[:user])
Unfortunately, if there is a user field called admin
which controls administrator access, now any user can make themselves an administrator.
attr_accessible
and attr_protected
can be used to limit mass assignment. However, Brakeman will warn unless attr_accessible
is used, or mass assignment is completely disabled.
There are two different mass assignment warnings which can arise. The first is when mass assignment actually occurs, such as the example above. This results in a warning like
Unprotected mass assignment near line 61: User.new(params[:user])
The other warning is raised whenever a model is found which does not use attr_accessible
. This produces generic warnings like
Mass assignment is not restricted using attr_accessible
with a list of affected models.
In Rails 3.1 and newer, mass assignment can easily be disabled:
config.active_record.whitelist_attributes = true
Unfortunately, it can also easily be bypassed:
User.new(params[:user], :without_protection => true)
Brakeman will warn on uses of without_protection
.
Unprotected mass assignment Open
user = User.new(user_params)
- Read upRead up
- Exclude checks
Mass assignment is a feature of Rails which allows an application to create a record from the values of a hash.
Example:
User.new(params[:user])
Unfortunately, if there is a user field called admin
which controls administrator access, now any user can make themselves an administrator.
attr_accessible
and attr_protected
can be used to limit mass assignment. However, Brakeman will warn unless attr_accessible
is used, or mass assignment is completely disabled.
There are two different mass assignment warnings which can arise. The first is when mass assignment actually occurs, such as the example above. This results in a warning like
Unprotected mass assignment near line 61: User.new(params[:user])
The other warning is raised whenever a model is found which does not use attr_accessible
. This produces generic warnings like
Mass assignment is not restricted using attr_accessible
with a list of affected models.
In Rails 3.1 and newer, mass assignment can easily be disabled:
config.active_record.whitelist_attributes = true
Unfortunately, it can also easily be bypassed:
User.new(params[:user], :without_protection => true)
Brakeman will warn on uses of without_protection
.
Complex method UsersController#create (108.6) Open
def create
if params['exception']
render_failure "Expected post format is valid xml like so: <user><login>username</login><password>abc123</password></user>."
return
end
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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
Block has too many lines. [52/25] Open
respond_to do |format|
format.html do
unless User.no_users_yet? || (@user && @user.is_admin?) || SITE_CONFIG['open_signups']
@page_title = t('users.no_signups_title')
@admin_email = SITE_CONFIG['admin_email']
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This cop checks if the length of a block exceeds some maximum value. Comment lines can optionally be ignored. The maximum allowed length is configurable. The cop can be configured to ignore blocks passed to certain methods.
Complex method UsersController#destroy (36.3) Open
def destroy
@deleted_user = User.find(params[:id])
# Remove the user
@saved = @deleted_user.destroy
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- Exclude checks
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
Complex method UsersController#index (33.3) Open
def index
respond_to do |format|
order_by = 'login'
if params[:order] && User.column_names.include?(params[:order])
order_by = params[:order]
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- Exclude checks
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
Complex method UsersController#new (26.2) Open
def new
@auth_types = []
unless session[:cas_user]
Tracks::Config.auth_schemes.each { |auth| @auth_types << [auth, auth] }
else
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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
UsersController has at least 9 instance variables Open
class UsersController < ApplicationController
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Too Many Instance Variables
is a special case of LargeClass
.
Example
Given this configuration
TooManyInstanceVariables:
max_instance_variables: 3
and this code:
class TooManyInstanceVariables
def initialize
@arg_1 = :dummy
@arg_2 = :dummy
@arg_3 = :dummy
@arg_4 = :dummy
end
end
Reek would emit the following warning:
test.rb -- 5 warnings:
[1]:TooManyInstanceVariables has at least 4 instance variables (TooManyInstanceVariables)
UsersController#create has approx 36 statements Open
def create
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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.)
UsersController#update_password has approx 6 statements Open
def update_password
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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.)
UsersController#new has approx 15 statements Open
def new
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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.)
UsersController#index has approx 11 statements Open
def index
- Read upRead up
- Exclude checks
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.)
UsersController#check_create_user_params has approx 6 statements Open
def check_create_user_params
- Read upRead up
- Exclude checks
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.)
UsersController#destroy has approx 13 statements Open
def destroy
- Read upRead up
- Exclude checks
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.)
Complex method UsersController#update_auth_type (25.0) Open
def update_auth_type
current_user.auth_type = user_params[:auth_type]
if current_user.save
notify :notice, t('users.auth_type_updated')
redirect_to preferences_path
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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
UsersController#create calls '@user.is_admin?' 2 times Open
unless User.no_users_yet? || (@user && @user.is_admin?) || SITE_CONFIG['open_signups']
@page_title = t('users.no_signups_title')
@admin_email = SITE_CONFIG['admin_email']
render :action => "nosignup", :layout => "login"
return
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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.
UsersController#create calls 'render_failure "You have to accept the terms of service to sign up!"' 2 times Open
render_failure "You have to accept the terms of service to sign up!"
return
end
user = User.new(user_params)
- Read upRead up
- Exclude checks
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.
UsersController assumes too much for instance variable '@deleted_user' Open
class UsersController < ApplicationController
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Classes should not assume that instance variables are set or present outside of the current class definition.
Good:
class Foo
def initialize
@bar = :foo
end
def foo?
@bar == :foo
end
end
Good as well:
class Foo
def foo?
bar == :foo
end
def bar
@bar ||= :foo
end
end
Bad:
class Foo
def go_foo!
@bar = :foo
end
def foo?
@bar == :foo
end
end
Example
Running Reek on:
class Dummy
def test
@ivar
end
end
would report:
[1]:InstanceVariableAssumption: Dummy assumes too much for instance variable @ivar
Note that this example would trigger this smell warning as well:
class Parent
def initialize(omg)
@omg = omg
end
end
class Child < Parent
def foo
@omg
end
end
The way to address the smell warning is that you should create an attr_reader
to use @omg
in the subclass and not access @omg
directly like this:
class Parent
attr_reader :omg
def initialize(omg)
@omg = omg
end
end
class Child < Parent
def foo
omg
end
end
Directly accessing instance variables is considered a smell because it breaks encapsulation and makes it harder to reason about code.
If you don't want to expose those methods as public API just make them private like this:
class Parent
def initialize(omg)
@omg = omg
end
private
attr_reader :omg
end
class Child < Parent
def foo
omg
end
end
Current Support in Reek
An instance variable must:
- be set in the constructor
- or be accessed through a method with lazy initialization / memoization.
If not, Instance Variable Assumption will be reported.
UsersController#destroy calls 'current_user == @deleted_user' 2 times Open
if @saved && current_user == @deleted_user
logout_user
end
respond_to do |format|
- Read upRead up
- Exclude checks
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.
UsersController#destroy calls '@deleted_user.login' 2 times Open
notify :notice, t('users.successfully_deleted_user', :username => @deleted_user.login)
else
notify :error, t('users.failed_to_delete_user', :username => @deleted_user.login)
- Read upRead up
- Exclude checks
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.
UsersController assumes too much for instance variable '@saved' Open
class UsersController < ApplicationController
- Read upRead up
- Exclude checks
Classes should not assume that instance variables are set or present outside of the current class definition.
Good:
class Foo
def initialize
@bar = :foo
end
def foo?
@bar == :foo
end
end
Good as well:
class Foo
def foo?
bar == :foo
end
def bar
@bar ||= :foo
end
end
Bad:
class Foo
def go_foo!
@bar = :foo
end
def foo?
@bar == :foo
end
end
Example
Running Reek on:
class Dummy
def test
@ivar
end
end
would report:
[1]:InstanceVariableAssumption: Dummy assumes too much for instance variable @ivar
Note that this example would trigger this smell warning as well:
class Parent
def initialize(omg)
@omg = omg
end
end
class Child < Parent
def foo
@omg
end
end
The way to address the smell warning is that you should create an attr_reader
to use @omg
in the subclass and not access @omg
directly like this:
class Parent
attr_reader :omg
def initialize(omg)
@omg = omg
end
end
class Child < Parent
def foo
omg
end
end
Directly accessing instance variables is considered a smell because it breaks encapsulation and makes it harder to reason about code.
If you don't want to expose those methods as public API just make them private like this:
class Parent
def initialize(omg)
@omg = omg
end
private
attr_reader :omg
end
class Child < Parent
def foo
omg
end
end
Current Support in Reek
An instance variable must:
- be set in the constructor
- or be accessed through a method with lazy initialization / memoization.
If not, Instance Variable Assumption will be reported.
UsersController#check_create_user_params calls 'params[:user]' 4 times Open
return false unless params[:user].key?(:login)
return false if params[:user][:login].empty?
return false unless params[:user].key?(:password)
return false if params[:user][:password].empty?
- Read upRead up
- Exclude checks
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.
UsersController#create calls 'SITE_CONFIG['tos_link'].blank?' 2 times Open
unless params['approve_tos'] == 'on' || SITE_CONFIG['tos_link'].blank?
render_failure "You have to accept the terms of service to sign up!"
return
end
- Read upRead up
- Exclude checks
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.
UsersController#create calls 'user.save' 2 times Open
if user.save
@user = User.authenticate(user.login, params['user']['password'])
@user.create_preference(:locale => I18n.locale)
@user.save
session['user_id'] = @user.id unless signup_by_admin
- Read upRead up
- Exclude checks
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.
UsersController#create calls 'SITE_CONFIG['tos_link']' 2 times Open
unless params['approve_tos'] == 'on' || SITE_CONFIG['tos_link'].blank?
render_failure "You have to accept the terms of service to sign up!"
return
end
- Read upRead up
- Exclude checks
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.
UsersController#index calls 'params[:order]' 3 times Open
if params[:order] && User.column_names.include?(params[:order])
order_by = params[:order]
- Read upRead up
- Exclude checks
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.
UsersController assumes too much for instance variable '@users' Open
class UsersController < ApplicationController
- Read upRead up
- Exclude checks
Classes should not assume that instance variables are set or present outside of the current class definition.
Good:
class Foo
def initialize
@bar = :foo
end
def foo?
@bar == :foo
end
end
Good as well:
class Foo
def foo?
bar == :foo
end
def bar
@bar ||= :foo
end
end
Bad:
class Foo
def go_foo!
@bar = :foo
end
def foo?
@bar == :foo
end
end
Example
Running Reek on:
class Dummy
def test
@ivar
end
end
would report:
[1]:InstanceVariableAssumption: Dummy assumes too much for instance variable @ivar
Note that this example would trigger this smell warning as well:
class Parent
def initialize(omg)
@omg = omg
end
end
class Child < Parent
def foo
@omg
end
end
The way to address the smell warning is that you should create an attr_reader
to use @omg
in the subclass and not access @omg
directly like this:
class Parent
attr_reader :omg
def initialize(omg)
@omg = omg
end
end
class Child < Parent
def foo
omg
end
end
Directly accessing instance variables is considered a smell because it breaks encapsulation and makes it harder to reason about code.
If you don't want to expose those methods as public API just make them private like this:
class Parent
def initialize(omg)
@omg = omg
end
private
attr_reader :omg
end
class Child < Parent
def foo
omg
end
end
Current Support in Reek
An instance variable must:
- be set in the constructor
- or be accessed through a method with lazy initialization / memoization.
If not, Instance Variable Assumption will be reported.
UsersController#create calls 'User.no_users_yet?' 2 times Open
unless User.no_users_yet? || (@user && @user.is_admin?) || SITE_CONFIG['open_signups']
@page_title = t('users.no_signups_title')
@admin_email = SITE_CONFIG['admin_email']
render :action => "nosignup", :layout => "login"
return
- Read upRead up
- Exclude checks
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.
UsersController has no descriptive comment Open
class UsersController < ApplicationController
- Read upRead up
- Exclude checks
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
UsersController assumes too much for instance variable '@user' Open
class UsersController < ApplicationController
- Read upRead up
- Exclude checks
Classes should not assume that instance variables are set or present outside of the current class definition.
Good:
class Foo
def initialize
@bar = :foo
end
def foo?
@bar == :foo
end
end
Good as well:
class Foo
def foo?
bar == :foo
end
def bar
@bar ||= :foo
end
end
Bad:
class Foo
def go_foo!
@bar = :foo
end
def foo?
@bar == :foo
end
end
Example
Running Reek on:
class Dummy
def test
@ivar
end
end
would report:
[1]:InstanceVariableAssumption: Dummy assumes too much for instance variable @ivar
Note that this example would trigger this smell warning as well:
class Parent
def initialize(omg)
@omg = omg
end
end
class Child < Parent
def foo
@omg
end
end
The way to address the smell warning is that you should create an attr_reader
to use @omg
in the subclass and not access @omg
directly like this:
class Parent
attr_reader :omg
def initialize(omg)
@omg = omg
end
end
class Child < Parent
def foo
omg
end
end
Directly accessing instance variables is considered a smell because it breaks encapsulation and makes it harder to reason about code.
If you don't want to expose those methods as public API just make them private like this:
class Parent
def initialize(omg)
@omg = omg
end
private
attr_reader :omg
end
class Child < Parent
def foo
omg
end
end
Current Support in Reek
An instance variable must:
- be set in the constructor
- or be accessed through a method with lazy initialization / memoization.
If not, Instance Variable Assumption will be reported.
UsersController#get_new_user calls 'session['new_user']' 2 times Open
if session['new_user']
user = session['new_user']
- Read upRead up
- Exclude checks
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.
UsersController assumes too much for instance variable '@auth_types' Open
class UsersController < ApplicationController
- Read upRead up
- Exclude checks
Classes should not assume that instance variables are set or present outside of the current class definition.
Good:
class Foo
def initialize
@bar = :foo
end
def foo?
@bar == :foo
end
end
Good as well:
class Foo
def foo?
bar == :foo
end
def bar
@bar ||= :foo
end
end
Bad:
class Foo
def go_foo!
@bar = :foo
end
def foo?
@bar == :foo
end
end
Example
Running Reek on:
class Dummy
def test
@ivar
end
end
would report:
[1]:InstanceVariableAssumption: Dummy assumes too much for instance variable @ivar
Note that this example would trigger this smell warning as well:
class Parent
def initialize(omg)
@omg = omg
end
end
class Child < Parent
def foo
@omg
end
end
The way to address the smell warning is that you should create an attr_reader
to use @omg
in the subclass and not access @omg
directly like this:
class Parent
attr_reader :omg
def initialize(omg)
@omg = omg
end
end
class Child < Parent
def foo
omg
end
end
Directly accessing instance variables is considered a smell because it breaks encapsulation and makes it harder to reason about code.
If you don't want to expose those methods as public API just make them private like this:
class Parent
def initialize(omg)
@omg = omg
end
private
attr_reader :omg
end
class Child < Parent
def foo
omg
end
end
Current Support in Reek
An instance variable must:
- be set in the constructor
- or be accessed through a method with lazy initialization / memoization.
If not, Instance Variable Assumption will be reported.
Avoid too many return
statements within this method. Open
return
Avoid too many return
statements within this method. Open
return
Avoid too many return
statements within this method. Open
return false if params[:user][:password].empty?
Avoid too many return
statements within this method. Open
return
Avoid too many return
statements within this method. Open
return
Avoid too many return
statements within this method. Open
return
Avoid too many return
statements within this method. Open
return true
Block has too many lines. [27/25] Open
format.html do
unless User.no_users_yet? || (@user && @user.is_admin?) || SITE_CONFIG['open_signups']
@page_title = t('users.no_signups_title')
@admin_email = SITE_CONFIG['admin_email']
render :action => "nosignup", :layout => "login"
- Read upRead up
- Exclude checks
This cop checks if the length of a block exceeds some maximum value. Comment lines can optionally be ignored. The maximum allowed length is configurable. The cop can be configured to ignore blocks passed to certain methods.
Complex method UsersController#check_create_user_params (20.4) Open
def check_create_user_params
return false unless params.key?(:user)
return false unless params[:user].key?(:login)
return false if params[:user][:login].empty?
return false unless params[:user].key?(:password)
- Read upRead up
- Exclude checks
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
Complex method UsersController#update_password (20.2) Open
def update_password
# is used for focing password change after sha->bcrypt upgrade
current_user.change_password(user_params[:password], user_params[:password_confirmation])
notify :notice, t('users.password_updated')
redirect_to preferences_path
- Read upRead up
- Exclude checks
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
Use safe navigation (&.
) instead of checking if an object exists before calling the method. Open
elsif (@user && @user.is_admin?) || SITE_CONFIG['open_signups']
- Read upRead up
- Exclude checks
This cop transforms usages of a method call safeguarded by a non nil
check for the variable whose method is being called to
safe navigation (&.
).
Configuration option: ConvertCodeThatCanStartToReturnNil
The default for this is false
. When configured to true
, this will
check for code in the format !foo.nil? && foo.bar
. As it is written,
the return of this code is limited to false
and whatever the return
of the method is. If this is converted to safe navigation,
foo&.bar
can start returning nil
as well as what the method
returns.
Example:
# bad
foo.bar if foo
foo.bar(param1, param2) if foo
foo.bar { |e| e.something } if foo
foo.bar(param) { |e| e.something } if foo
foo.bar if !foo.nil?
foo.bar unless !foo
foo.bar unless foo.nil?
foo && foo.bar
foo && foo.bar(param1, param2)
foo && foo.bar { |e| e.something }
foo && foo.bar(param) { |e| e.something }
# good
foo&.bar
foo&.bar(param1, param2)
foo&.bar { |e| e.something }
foo&.bar(param) { |e| e.something }
foo.nil? || foo.bar
!foo || foo.bar
# Methods that `nil` will `respond_to?` should not be converted to
# use safe navigation
foo.to_i if foo
Use safe navigation (&.
) instead of checking if an object exists before calling the method. Open
signup_by_admin = true if @user && @user.is_admin?
- Read upRead up
- Exclude checks
This cop transforms usages of a method call safeguarded by a non nil
check for the variable whose method is being called to
safe navigation (&.
).
Configuration option: ConvertCodeThatCanStartToReturnNil
The default for this is false
. When configured to true
, this will
check for code in the format !foo.nil? && foo.bar
. As it is written,
the return of this code is limited to false
and whatever the return
of the method is. If this is converted to safe navigation,
foo&.bar
can start returning nil
as well as what the method
returns.
Example:
# bad
foo.bar if foo
foo.bar(param1, param2) if foo
foo.bar { |e| e.something } if foo
foo.bar(param) { |e| e.something } if foo
foo.bar if !foo.nil?
foo.bar unless !foo
foo.bar unless foo.nil?
foo && foo.bar
foo && foo.bar(param1, param2)
foo && foo.bar { |e| e.something }
foo && foo.bar(param) { |e| e.something }
# good
foo&.bar
foo&.bar(param1, param2)
foo&.bar { |e| e.something }
foo&.bar(param) { |e| e.something }
foo.nil? || foo.bar
!foo || foo.bar
# Methods that `nil` will `respond_to?` should not be converted to
# use safe navigation
foo.to_i if foo
Redundant return
detected. Open
return true
- Read upRead up
- Exclude checks
This cop checks for redundant return
expressions.
Example:
def test
return something
end
def test
one
two
three
return something
end
It should be extended to handle methods whose body is if/else or a case expression with a default branch.
Use %i
or %I
for an array of symbols. Open
skip_before_action :login_required, :only => [:new, :create]
- Read upRead up
- Exclude checks
This cop can check for array literals made up of symbols that are not using the %i() syntax.
Alternatively, it checks for symbol arrays using the %i() syntax on projects which do not want to use that syntax.
Configuration option: MinSize
If set, arrays with fewer elements than this value will not trigger the
cop. For example, a MinSize of
3` will not enforce a style on an array
of 2 or fewer elements.
Example: EnforcedStyle: percent (default)
# good
%i[foo bar baz]
# bad
[:foo, :bar, :baz]
Example: EnforcedStyle: brackets
# good
[:foo, :bar, :baz]
# bad
%i[foo bar baz]
Do not use unless
with else
. Rewrite these with the positive case first. Open
unless user.new_record?
render :body => t('users.user_created'), :status => 200
else
render_failure user.errors.to_xml, 409
end
- Read upRead up
- Exclude checks
This cop looks for unless expressions with else clauses.
Example:
# bad
unless foo_bar.nil?
# do something...
else
# do a different thing...
end
# good
if foo_bar.present?
# do something...
else
# do a different thing...
end
Line is too long. [121/120] Open
notify :warning, t('users.auth_type_update_error', :error_messages => current_user.errors.full_messages.join(', '))
- Exclude checks
Do not use unless
with else
. Rewrite these with the positive case first. Open
unless session[:cas_user]
Tracks::Config.auth_schemes.each { |auth| @auth_types << [auth, auth] }
else
@auth_types << ['cas', 'cas']
end
- Read upRead up
- Exclude checks
This cop looks for unless expressions with else clauses.
Example:
# bad
unless foo_bar.nil?
# do something...
else
# do a different thing...
end
# good
if foo_bar.present?
# do something...
else
# do a different thing...
end
Missing magic comment # frozen_string_literal: true
. Open
class UsersController < ApplicationController
- Read upRead up
- Exclude checks
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
Use %i
or %I
for an array of symbols. Open
prepend_before_action :login_optional, :only => [:new, :create]
- Read upRead up
- Exclude checks
This cop can check for array literals made up of symbols that are not using the %i() syntax.
Alternatively, it checks for symbol arrays using the %i() syntax on projects which do not want to use that syntax.
Configuration option: MinSize
If set, arrays with fewer elements than this value will not trigger the
cop. For example, a MinSize of
3` will not enforce a style on an array
of 2 or fewer elements.
Example: EnforcedStyle: percent (default)
# good
%i[foo bar baz]
# bad
[:foo, :bar, :baz]
Example: EnforcedStyle: brackets
# good
[:foo, :bar, :baz]
# bad
%i[foo bar baz]
Avoid rescuing the Exception
class. Perhaps you meant to rescue StandardError
? Open
rescue Exception => error
notify :error, error.message
redirect_to change_password_user_path(current_user)
- Read upRead up
- Exclude checks
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
Line is too long. [134/120] Open
params.require(:user).permit(:login, :first_name, :last_name, :email, :password_confirmation, :password, :auth_type, :open_id_url)
- Exclude checks
Line is too long. [139/120] Open
render_failure "Expected post format is valid xml like so: <user><login>username</login><password>abc123</password></user>.", 400
- Exclude checks
Use safe navigation (&.
) instead of checking if an object exists before calling the method. Open
unless User.no_users_yet? || (@user && @user.is_admin?) || SITE_CONFIG['open_signups']
- Read upRead up
- Exclude checks
This cop transforms usages of a method call safeguarded by a non nil
check for the variable whose method is being called to
safe navigation (&.
).
Configuration option: ConvertCodeThatCanStartToReturnNil
The default for this is false
. When configured to true
, this will
check for code in the format !foo.nil? && foo.bar
. As it is written,
the return of this code is limited to false
and whatever the return
of the method is. If this is converted to safe navigation,
foo&.bar
can start returning nil
as well as what the method
returns.
Example:
# bad
foo.bar if foo
foo.bar(param1, param2) if foo
foo.bar { |e| e.something } if foo
foo.bar(param) { |e| e.something } if foo
foo.bar if !foo.nil?
foo.bar unless !foo
foo.bar unless foo.nil?
foo && foo.bar
foo && foo.bar(param1, param2)
foo && foo.bar { |e| e.something }
foo && foo.bar(param) { |e| e.something }
# good
foo&.bar
foo&.bar(param1, param2)
foo&.bar { |e| e.something }
foo&.bar(param) { |e| e.something }
foo.nil? || foo.bar
!foo || foo.bar
# Methods that `nil` will `respond_to?` should not be converted to
# use safe navigation
foo.to_i if foo
Favor modifier if
usage when having a single-line body. Another good alternative is the usage of control flow &&
/||
. Open
if params[:order] && User.column_names.include?(params[:order])
- Read upRead up
- Exclude checks
Checks for if and unless statements that would fit on one line
if written as a modifier if/unless. The maximum line length is
configured in the Metrics/LineLength
cop.
Example:
# bad
if condition
do_stuff(bar)
end
unless qux.empty?
Foo.do_something
end
# good
do_stuff(bar) if condition
Foo.do_something unless qux.empty?
Use safe navigation (&.
) instead of checking if an object exists before calling the method. Open
unless current_user && current_user.is_admin
- Read upRead up
- Exclude checks
This cop transforms usages of a method call safeguarded by a non nil
check for the variable whose method is being called to
safe navigation (&.
).
Configuration option: ConvertCodeThatCanStartToReturnNil
The default for this is false
. When configured to true
, this will
check for code in the format !foo.nil? && foo.bar
. As it is written,
the return of this code is limited to false
and whatever the return
of the method is. If this is converted to safe navigation,
foo&.bar
can start returning nil
as well as what the method
returns.
Example:
# bad
foo.bar if foo
foo.bar(param1, param2) if foo
foo.bar { |e| e.something } if foo
foo.bar(param) { |e| e.something } if foo
foo.bar if !foo.nil?
foo.bar unless !foo
foo.bar unless foo.nil?
foo && foo.bar
foo && foo.bar(param1, param2)
foo && foo.bar { |e| e.something }
foo && foo.bar(param) { |e| e.something }
# good
foo&.bar
foo&.bar(param1, param2)
foo&.bar { |e| e.something }
foo&.bar(param) { |e| e.something }
foo.nil? || foo.bar
!foo || foo.bar
# Methods that `nil` will `respond_to?` should not be converted to
# use safe navigation
foo.to_i if foo
Useless assignment to variable - saved
. Open
saved = user.save
- Read upRead up
- Exclude checks
This cop checks for every useless assignment to local variable in every
scope.
The basic idea for this cop was from the warning of ruby -cw
:
assigned but unused variable - foo
Currently this cop has advanced logic that detects unreferenced reassignments and properly handles varied cases such as branch, loop, rescue, ensure, etc.
Example:
# bad
def some_method
some_var = 1
do_something
end
Example:
# good
def some_method
some_var = 1
do_something(some_var)
end
Use %w
or %W
for an array of words. Open
@auth_types << ['cas', 'cas']
- Read upRead up
- Exclude checks
This cop can check for array literals made up of word-like strings, that are not using the %w() syntax.
Alternatively, it can check for uses of the %w() syntax, in projects which do not want to include that syntax.
Configuration option: MinSize
If set, arrays with fewer elements than this value will not trigger the
cop. For example, a MinSize
of 3
will not enforce a style on an
array of 2 or fewer elements.
Example: EnforcedStyle: percent (default)
# good
%w[foo bar baz]
# bad
['foo', 'bar', 'baz']
Example: EnforcedStyle: brackets
# good
['foo', 'bar', 'baz']
# bad
%w[foo bar baz]
Do not prefix reader method names with get_
. Open
def get_new_user
- Read upRead up
- Exclude checks
This cop makes sure that accessor methods are named properly.
Example:
# bad
def set_attribute(value)
end
# good
def attribute=(value)
end
# bad
def get_attribute
end
# good
def attribute
end
Line is too long. [130/120] Open
render_failure "Expected post format is valid xml like so: <user><login>username</login><password>abc123</password></user>."
- Exclude checks
Favor modifier if
usage when having a single-line body. Another good alternative is the usage of control flow &&
/||
. Open
if @saved && current_user == @deleted_user
- Read upRead up
- Exclude checks
Checks for if and unless statements that would fit on one line
if written as a modifier if/unless. The maximum line length is
configured in the Metrics/LineLength
cop.
Example:
# bad
if condition
do_stuff(bar)
end
unless qux.empty?
Foo.do_something
end
# good
do_stuff(bar) if condition
Foo.do_something unless qux.empty?
Use %i
or %I
for an array of symbols. Open
before_action :admin_login_required, :only => [:index, :show]
- Read upRead up
- Exclude checks
This cop can check for array literals made up of symbols that are not using the %i() syntax.
Alternatively, it checks for symbol arrays using the %i() syntax on projects which do not want to use that syntax.
Configuration option: MinSize
If set, arrays with fewer elements than this value will not trigger the
cop. For example, a MinSize of
3` will not enforce a style on an array
of 2 or fewer elements.
Example: EnforcedStyle: percent (default)
# good
%i[foo bar baz]
# bad
[:foo, :bar, :baz]
Example: EnforcedStyle: brackets
# good
[:foo, :bar, :baz]
# bad
%i[foo bar baz]