Datasets:
gadams
/
ruby

Dataset card Data Studio Files
xet
Community
text
stringlengths
0
444
end
# good
File.binwrite(filename, content)
----
=== Release External Resources [[release-resources]]
Release external resources obtained by your program in an `ensure` block.
[source,ruby]
----
f = File.open('testfile')
begin
# .. process
rescue
# .. handle error
ensure
f.close if f
end
----
=== Auto-release External Resources [[auto-release-resources]]
Use versions of resource obtaining methods that do automatic resource cleanup when possible.
[source,ruby]
----
# bad - you need to close the file descriptor explicitly
f = File.open('testfile')
# some action on the file
f.close
# good - the file descriptor is closed automatically
File.open('testfile') do |f|
# some action on the file
end
----
=== Atomic File Operations [[atomic-file-operations]]
When doing file operations after confirming the existence check of a file, frequent parallel file operations may cause problems that are difficult to reproduce.
Therefore, it is preferable to use atomic file operations.
[source,ruby]
----
# bad - race condition with another process may result in an error in `mkdir`
unless Dir.exist?(path)
FileUtils.mkdir(path)
end
# good - atomic and idempotent creation
FileUtils.mkdir_p(path)
# bad - race condition with another process may result in an error in `remove`
if File.exist?(path)
FileUtils.remove(path)
end
# good - atomic and idempotent removal
FileUtils.rm_f(path)
----
=== Standard Exceptions [[standard-exceptions]]
Prefer the use of exceptions from the standard library over introducing new exception classes.
== Assignment & Comparison
=== Parallel Assignment [[parallel-assignment]]
Avoid the use of parallel assignment for defining variables.
Parallel assignment is allowed when it is the return of a method call, used with the splat operator, or when used to swap variable assignment.
Parallel assignment is less readable than separate assignment.
[source,ruby]
----
# bad
a, b, c, d = 'foo', 'bar', 'baz', 'foobar'
# good
a = 'foo'
b = 'bar'
c = 'baz'
d = 'foobar'
# good - swapping variable assignment
# Swapping variable assignment is a special case because it will allow you to
# swap the values that are assigned to each variable.
a = 'foo'
b = 'bar'
a, b = b, a
puts a # => 'bar'
puts b # => 'foo'
# good - method return
def multi_return
[1, 2]
end