Use each_key
instead of keys.each
. Open
h.keys.each { |k| h[k].is_a?(Array) && !h[k].empty? }.each do |list_key|
- Read upRead up
- Exclude checks
This cop checks for uses of each_key
and each_value
Hash methods.
Note: If you have an array of two-element arrays, you can put parentheses around the block arguments to indicate that you're not working with a hash, and suppress RuboCop offenses.
Example:
# bad
hash.keys.each { |k| p k }
hash.values.each { |v| p v }
hash.each { |k, _v| p k }
hash.each { |_k, v| p v }
# good
hash.each_key { |k| p k }
hash.each_value { |v| p v }
Use results.size.positive?
instead of results.size > 0
. Open
results.is_a?(Array) && results.size > 0 ? results.first : nil
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- 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
Freeze mutable objects assigned to constants. Open
MATCHERS = [
->(key) {
case key.to_sym
when :items
:customs_items
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- Exclude checks
This cop checks whether some constant value isn't a mutable literal (e.g. array or hash).
Example:
# bad
CONST = [1, 2, 3]
# good
CONST = [1, 2, 3].freeze
Use !empty?
instead of size > 0
. Open
results.is_a?(Array) && results.size > 0 ? results.first : nil
- Read upRead up
- Exclude checks
This cop checks for numeric comparisons that can be replaced by a predicate method, such as receiver.length == 0, receiver.length > 0, receiver.length != 0, receiver.length < 1 and receiver.size == 0 that can be replaced by receiver.empty? and !receiver.empty.
Example:
# bad
[1, 2, 3].length == 0
0 == "foobar".length
array.length < 1
{a: 1, b: 2}.length != 0
string.length > 0
hash.size > 0
# good
[1, 2, 3].empty?
"foobar".empty?
array.empty?
!{a: 1, b: 2}.empty?
!string.empty?
!hash.empty?