Use =~
in places where the MatchData
returned by #match
will not be used. Open
if url.match(/^\w+:\/\//)
- Read upRead up
- Exclude checks
This cop identifies the use of Regexp#match
or String#match
, which
returns #<MatchData>
/nil
. The return value of =~
is an integral
index/nil
and is more performant.
Example:
# bad
do_something if str.match(/regex/)
while regex.match('str')
do_something
end
# good
method(str =~ /regex/)
return value unless regex =~ 'str'
Use %r
around regular expression. Open
if url.match(/^\w+:\/\//)
- Read upRead up
- Exclude checks
This cop enforces using // or %r around regular expressions.
Example: EnforcedStyle: slashes (default)
# bad
snake_case = %r{^[\dA-Z_]+$}
# bad
regex = %r{
foo
(bar)
(baz)
}x
# good
snake_case = /^[\dA-Z_]+$/
# good
regex = /
foo
(bar)
(baz)
/x
Example: EnforcedStyle: percent_r
# bad
snake_case = /^[\dA-Z_]+$/
# bad
regex = /
foo
(bar)
(baz)
/x
# good
snake_case = %r{^[\dA-Z_]+$}
# good
regex = %r{
foo
(bar)
(baz)
}x
Example: EnforcedStyle: mixed
# bad
snake_case = %r{^[\dA-Z_]+$}
# bad
regex = /
foo
(bar)
(baz)
/x
# good
snake_case = /^[\dA-Z_]+$/
# good
regex = %r{
foo
(bar)
(baz)
}x
Example: AllowInnerSlashes: false (default)
# If `false`, the cop will always recommend using `%r` if one or more
# slashes are found in the regexp string.
# bad
x =~ /home\//
# good
x =~ %r{home/}
Example: AllowInnerSlashes: true
# good
x =~ /home\//
Prefer single-quoted strings when you don't need string interpolation or special symbols. Open
""
- Read upRead up
- Exclude checks
Checks if uses of quotes match the configured preference.
Example: EnforcedStyle: single_quotes (default)
# bad
"No special symbols"
"No string interpolation"
"Just text"
# good
'No special symbols'
'No string interpolation'
'Just text'
"Wait! What's #{this}!"
Example: EnforcedStyle: double_quotes
# bad
'Just some text'
'No special chars or interpolation'
# good
"Just some text"
"No special chars or interpolation"
"Every string in #{project} uses double_quotes"
Missing top-level module documentation comment. Open
module Utils
- 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 module_function
instead of extend self
. Open
extend self
- Read upRead up
- Exclude checks
This cops checks for use of extend self
or module_function
in a
module.
Supported styles are: modulefunction, extendself.
Example: EnforcedStyle: module_function (default)
# bad
module Test
extend self
# ...
end
# good
module Test
module_function
# ...
end
Example: EnforcedStyle: extend_self
# bad
module Test
module_function
# ...
end
# good
module Test
extend self
# ...
end
These offenses are not auto-corrected since there are different implications to each approach.
Avoid the use of Perl-style backrefs. Open
format = $1
- Read upRead up
- Exclude checks
This cop looks for uses of Perl-style regexp match backreferences like $1, $2, etc.
Example:
# bad
puts $1
# good
puts Regexp.last_match(1)
Extra empty line detected at module body end. Open
end
- Read upRead up
- Exclude checks
This cops checks if empty lines around the bodies of modules match the configuration.
Example: EnforcedStyle: empty_lines
# good
module Foo
def bar
# ...
end
end
Example: EnforcedStyle: emptylinesexcept_namespace
# good
module Foo
module Bar
# ...
end
end
Example: EnforcedStyle: emptylinesspecial
# good
module Foo
def bar; end
end
Example: EnforcedStyle: noemptylines (default)
# good
module Foo
def bar
# ...
end
end