Use &&
instead of and
. Open
(stat.uid == 0 and stat.gid == 0) ||
- Read upRead up
- Exclude checks
This cop checks for uses of and
and or
, and suggests using &&
and
|| instead
. It can be configured to check only in conditions, or in
all contexts.
Example: EnforcedStyle: always (default)
# bad
foo.save and return
# bad
if foo and bar
end
# good
foo.save && return
# good
if foo && bar
end
Example: EnforcedStyle: conditionals
# bad
if foo and bar
end
# good
foo.save && return
# good
foo.save and return
# good
if foo && bar
end
Space inside string interpolation detected. Open
"#{ message } #{ backtrace&.join "\n" }"
- Read upRead up
- Exclude checks
This cop checks for whitespace within string interpolations.
Example: EnforcedStyle: no_space (default)
# bad
var = "This is the #{ space } example"
# good
var = "This is the #{no_space} example"
Example: EnforcedStyle: space
# bad
var = "This is the #{no_space} example"
# good
var = "This is the #{ space } example"
Use &&
instead of and
. Open
(stat.uid == Process.uid and stat.gid == Process.gid)
- Read upRead up
- Exclude checks
This cop checks for uses of and
and or
, and suggests using &&
and
|| instead
. It can be configured to check only in conditions, or in
all contexts.
Example: EnforcedStyle: always (default)
# bad
foo.save and return
# bad
if foo and bar
end
# good
foo.save && return
# good
if foo && bar
end
Example: EnforcedStyle: conditionals
# bad
if foo and bar
end
# good
foo.save && return
# good
foo.save and return
# good
if foo && bar
end
Missing magic comment # frozen_string_literal: true
. Open
class Exception
- 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
Space inside string interpolation detected. Open
"#{ message } #{ backtrace&.join "\n" }"
- Read upRead up
- Exclude checks
This cop checks for whitespace within string interpolations.
Example: EnforcedStyle: no_space (default)
# bad
var = "This is the #{ space } example"
# good
var = "This is the #{no_space} example"
Example: EnforcedStyle: space
# bad
var = "This is the #{no_space} example"
# good
var = "This is the #{ space } example"
Missing top-level class documentation comment. Open
class Exception
- Read upRead up
- Exclude checks
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
Use def with parentheses when there are parameters. Open
def log_ex e
- Read upRead up
- 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
Use stat.uid.zero?
instead of stat.uid == 0
. Open
(stat.uid == 0 and stat.gid == 0) ||
- Read upRead up
- Exclude checks
This cop checks for usage of comparison operators (==
,
>
, <
) to test numbers as zero, positive, or negative.
These can be replaced by their respective predicate methods.
The cop can also be configured to do the reverse.
The cop disregards #nonzero?
as it its value is truthy or falsey,
but not true
and false
, and thus not always interchangeable with
!= 0
.
The cop ignores comparisons to global variables, since they are often
populated with objects which can be compared with integers, but are
not themselves Interger
polymorphic.
Example: EnforcedStyle: predicate (default)
# bad
foo == 0
0 > foo
bar.baz > 0
# good
foo.zero?
foo.negative?
bar.baz.positive?
Example: EnforcedStyle: comparison
# bad
foo.zero?
foo.negative?
bar.baz.positive?
# good
foo == 0
0 > foo
bar.baz > 0
Use 2 (not 0) spaces for indenting an expression spanning multiple lines. Open
(stat.uid == Process.uid and stat.gid == Process.gid)
- Read upRead up
- Exclude checks
This cop checks the indentation of the right hand side operand in binary operations that span more than one line.
Example:
# bad
if a +
b
something
end
# good
if a +
b
something
end
Use stat.gid.zero?
instead of stat.gid == 0
. Open
(stat.uid == 0 and stat.gid == 0) ||
- Read upRead up
- Exclude checks
This cop checks for usage of comparison operators (==
,
>
, <
) to test numbers as zero, positive, or negative.
These can be replaced by their respective predicate methods.
The cop can also be configured to do the reverse.
The cop disregards #nonzero?
as it its value is truthy or falsey,
but not true
and false
, and thus not always interchangeable with
!= 0
.
The cop ignores comparisons to global variables, since they are often
populated with objects which can be compared with integers, but are
not themselves Interger
polymorphic.
Example: EnforcedStyle: predicate (default)
# bad
foo == 0
0 > foo
bar.baz > 0
# good
foo.zero?
foo.negative?
bar.baz.positive?
Example: EnforcedStyle: comparison
# bad
foo.zero?
foo.negative?
bar.baz.positive?
# good
foo == 0
0 > foo
bar.baz > 0
Use def with parentheses when there are parameters. Open
def match_root_or_current_user stat
- Read upRead up
- 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