text
stringlengths
0
444
end
----
NOTE: The only valid use-case for the stream constants is obtaining references to the original streams (assuming you've redirected some of the global vars).
=== Warn [[warn]]
Use `warn` instead of `$stderr.puts`.
Apart from being more concise and clear, `warn` allows you to suppress warnings if you need to (by setting the warn level to 0 via `-W0`).
[source,ruby]
----
# bad
$stderr.puts 'This is a warning!'
# good
warn 'This is a warning!'
----
=== `Array#join` [[array-join]]
Prefer the use of `Array#join` over the fairly cryptic `Array#*` with a string argument.
[source,ruby]
----
# bad
%w[one two three] * ', '
# => 'one, two, three'
# good
%w[one two three].join(', ')
# => 'one, two, three'
----
=== Array Coercion [[array-coercion]]
Use `Array()` instead of explicit `Array` check or `[*var]`, when dealing with a variable you want to treat as an Array, but you're not certain it's an array.
[source,ruby]
----
# bad
paths = [paths] unless paths.is_a?(Array)
paths.each { |path| do_something(path) }
# bad (always creates a new Array instance)
[*paths].each { |path| do_something(path) }
# good (and a bit more readable)
Array(paths).each { |path| do_something(path) }
----
=== Ranges or `between` [[ranges-or-between]]
Use ranges or `Comparable#between?` instead of complex comparison logic when possible.
[source,ruby]
----
# bad
do_something if x >= 1000 && x <= 2000
# good
do_something if (1000..2000).include?(x)
# good
do_something if x.between?(1000, 2000)
----
=== Predicate Methods [[predicate-methods]]
Prefer the use of predicate methods to explicit comparisons with `==`.
Numeric comparisons are OK.
[source,ruby]
----
# bad
if x % 2 == 0
end
if x % 2 == 1
end
if x == nil
end
# good
if x.even?
end
if x.odd?
end
if x.nil?
end
if x.zero?
end
if x == 0
end
----