Prefer single-quoted strings when you don't need string interpolation or special symbols. Open
errors.add :user_authentication, "invalid credentials"
- 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"
Use a guard clause instead of wrapping the code inside a conditional expression. Open
if authenticate_new_user
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- Exclude checks
Use a guard clause instead of wrapping the code inside a conditional expression
Example:
# bad
def test
if something
work
end
end
# good
def test
return unless something
work
end
# also good
def test
work if something
end
# bad
if something
raise 'exception'
else
ok
end
# good
raise 'exception' if something
ok
Missing magic comment # frozen_string_literal: true
. Open
class AuthenticateNewUser
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- 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
Favor modifier if
usage when having a single-line body. Another good alternative is the usage of control flow &&
/||
. Open
if authenticate_new_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?
Missing top-level class documentation comment. Open
class AuthenticateNewUser
- 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