Showing 107 of 107 total issues
Prefer {...}
over do...end
for functional blocks. Open
languages = config.fetch("config", {}).fetch("languages") do
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- Exclude checks
Check for uses of braces or do/end around single line or multi-line blocks.
Example: EnforcedStyle: linecountbased (default)
# bad - single line block
items.each do |item| item / 5 end
# good - single line block
items.each { |item| item / 5 }
# bad - multi-line block
things.map { |thing|
something = thing.some_method
process(something)
}
# good - multi-line block
things.map do |thing|
something = thing.some_method
process(something)
end
Example: EnforcedStyle: semantic
# Prefer `do...end` over `{...}` for procedural blocks.
# return value is used/assigned
# bad
foo = map do |x|
x
end
puts (map do |x|
x
end)
# return value is not used out of scope
# good
map do |x|
x
end
# Prefer `{...}` over `do...end` for functional blocks.
# return value is not used out of scope
# bad
each { |x|
x
}
# return value is used/assigned
# good
foo = map { |x|
x
}
map { |x|
x
}.inspect
Example: EnforcedStyle: bracesforchaining
# bad
words.each do |word|
word.flip.flop
end.join("-")
# good
words.each { |word|
word.flip.flop
}.join("-")
end
at 38, 12 is not aligned with if
at 33, 10. Open
end
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This cop checks whether the end keywords are aligned properly.
Three modes are supported through the EnforcedStyleAlignWith
configuration parameter:
If it's set to keyword
(which is the default), the end
shall be aligned with the start of the keyword (if, class, etc.).
If it's set to variable
the end
shall be aligned with the
left-hand-side of the variable assignment, if there is one.
If it's set to start_of_line
, the end
shall be aligned with the
start of the line where the matching keyword appears.
Example: EnforcedStyleAlignWith: keyword (default)
# bad
variable = if true
end
# good
variable = if true
end
Example: EnforcedStyleAlignWith: variable
# bad
variable = if true
end
# good
variable = if true
end
Example: EnforcedStyleAlignWith: startofline
# bad
variable = if true
end
# good
puts(if true
end)
Avoid the use of Perl-style backrefs. Open
$1
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- 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)
Use def with parentheses when there are parameters. Open
def post_filter *patterns
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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
Redundant self
detected. Open
self.hashes.delete_if { |_, sexps|
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- Exclude checks
This cop checks for redundant uses of self
.
The usage of self
is only needed when:
Sending a message to same object with zero arguments in presence of a method name clash with an argument or a local variable.
Calling an attribute writer to prevent an local variable assignment.
Note, with using explicit self you can only send messages with public or protected scope, you cannot send private messages this way.
Note we allow uses of self
with operators because it would be awkward
otherwise.
Example:
# bad
def foo(bar)
self.baz
end
# good
def foo(bar)
self.bar # Resolves name clash with the argument.
end
def foo
bar = 1
self.bar # Resolves name clash with the local variable.
end
def foo
%w[x y z].select do |bar|
self.bar == bar # Resolves name clash with argument of the block.
end
end
Missing magic comment # frozen_string_literal: true
. Open
module CC
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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
Remove unnecessary require
statement. Open
require "thread"
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- Exclude checks
Checks for unnecessary require
statement.
The following features are unnecessary require
statement because
they are already loaded.
ruby -ve 'p $LOADED_FEATURES.reject { |feature| %r|/| =~ feature }' ruby 2.2.8p477 (2017-09-14 revision 59906) [x86_64-darwin13] ["enumerator.so", "rational.so", "complex.so", "thread.rb"]
This cop targets Ruby 2.2 or higher containing these 4 features.
Example:
# bad
require 'unloaded_feature'
require 'thread'
# good
require 'unloaded_feature'
Do not freeze immutable objects, as freezing them has no effect. Open
"(PACKAGE_DIRECTIVE ___)".freeze,
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- Exclude checks
This cop check for uses of Object#freeze on immutable objects.
Example:
# bad
CONST = 1.freeze
# good
CONST = 1
Do not freeze immutable objects, as freezing them has no effect. Open
"(EOL_COMMENT ___)".freeze,
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- Exclude checks
This cop check for uses of Object#freeze on immutable objects.
Example:
# bad
CONST = 1.freeze
# good
CONST = 1
Do not freeze immutable objects, as freezing them has no effect. Open
SIMILAR_CODE_CHECK = "similar-code".freeze
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- Exclude checks
This cop check for uses of Object#freeze on immutable objects.
Example:
# bad
CONST = 1.freeze
# good
CONST = 1
Avoid the use of Perl-style backrefs. Open
$1.to_sym
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- 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)
Do not freeze immutable objects, as freezing them has no effect. Open
MINOR = "minor".freeze,
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- Exclude checks
This cop check for uses of Object#freeze on immutable objects.
Example:
# bad
CONST = 1.freeze
# good
CONST = 1
Avoid rescuing without specifying an error class. Open
rescue => ex
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- Exclude checks
This cop checks for rescuing StandardError
. There are two supported
styles implicit
and explicit
. This cop will not register an offense
if any error other than StandardError
is specified.
Example: EnforcedStyle: implicit
# `implicit` will enforce using `rescue` instead of
# `rescue StandardError`.
# bad
begin
foo
rescue StandardError
bar
end
# good
begin
foo
rescue
bar
end
# good
begin
foo
rescue OtherError
bar
end
# good
begin
foo
rescue StandardError, SecurityError
bar
end
Example: EnforcedStyle: explicit (default)
# `explicit` will enforce using `rescue StandardError`
# instead of `rescue`.
# bad
begin
foo
rescue
bar
end
# good
begin
foo
rescue StandardError
bar
end
# good
begin
foo
rescue OtherError
bar
end
# good
begin
foo
rescue StandardError, SecurityError
bar
end
Avoid rescuing the Exception
class. Perhaps you meant to rescue StandardError
? Open
rescue Exception => ex
CC.logger.warn("Error processing file: #{file}")
raise ex
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- 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
Prefer {...}
over do...end
for functional blocks. Open
locs = issue.locations.map.with_index do |loc, idx2|
- Read upRead up
- Exclude checks
Check for uses of braces or do/end around single line or multi-line blocks.
Example: EnforcedStyle: linecountbased (default)
# bad - single line block
items.each do |item| item / 5 end
# good - single line block
items.each { |item| item / 5 }
# bad - multi-line block
things.map { |thing|
something = thing.some_method
process(something)
}
# good - multi-line block
things.map do |thing|
something = thing.some_method
process(something)
end
Example: EnforcedStyle: semantic
# Prefer `do...end` over `{...}` for procedural blocks.
# return value is used/assigned
# bad
foo = map do |x|
x
end
puts (map do |x|
x
end)
# return value is not used out of scope
# good
map do |x|
x
end
# Prefer `{...}` over `do...end` for functional blocks.
# return value is not used out of scope
# bad
each { |x|
x
}
# return value is used/assigned
# good
foo = map { |x|
x
}
map { |x|
x
}.inspect
Example: EnforcedStyle: bracesforchaining
# bad
words.each do |word|
word.flip.flop
end.join("-")
# good
words.each { |word|
word.flip.flop
}.join("-")
Avoid comma after the last item of a hash. Open
"end": sexp.end_line,
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- Exclude checks
This cop checks for trailing comma in array and hash literals.
Example: EnforcedStyleForMultiline: consistent_comma
# bad
a = [1, 2,]
# good
a = [
1, 2,
3,
]
# good
a = [
1,
2,
]
Example: EnforcedStyleForMultiline: comma
# bad
a = [1, 2,]
# good
a = [
1,
2,
]
Example: EnforcedStyleForMultiline: no_comma (default)
# bad
a = [1, 2,]
# good
a = [
1,
2
]
Remove unnecessary require
statement. Open
require "thread"
- Read upRead up
- Exclude checks
Checks for unnecessary require
statement.
The following features are unnecessary require
statement because
they are already loaded.
ruby -ve 'p $LOADED_FEATURES.reject { |feature| %r|/| =~ feature }' ruby 2.2.8p477 (2017-09-14 revision 59906) [x86_64-darwin13] ["enumerator.so", "rational.so", "complex.so", "thread.rb"]
This cop targets Ruby 2.2 or higher containing these 4 features.
Example:
# bad
require 'unloaded_feature'
require 'thread'
# good
require 'unloaded_feature'
Do not freeze immutable objects, as freezing them has no effect. Open
"(VariableDeclarator _ (init (CallExpression (_ (Identifier require)) ___)))".freeze,
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- Exclude checks
This cop check for uses of Object#freeze on immutable objects.
Example:
# bad
CONST = 1.freeze
# good
CONST = 1
Do not freeze immutable objects, as freezing them has no effect. Open
"(ImportDeclaration ___)".freeze,
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- Exclude checks
This cop check for uses of Object#freeze on immutable objects.
Example:
# bad
CONST = 1.freeze
# good
CONST = 1
Missing magic comment # frozen_string_literal: true
. Open
require "cc/parser"
- 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