Remove unnecessary existence check Dir.exist?
. Open
FileUtils.mkdir(PostgresAdmin.data_directory) unless Dir.exist?(PostgresAdmin.data_directory)
- Read upRead up
- Create a ticketCreate a ticket
- Exclude checks
Checks for non-atomic file operation. And then replace it with a nearly equivalent and atomic method.
These can cause problems that are difficult to reproduce, especially in cases of frequent file operations in parallel, such as test runs with parallel_rspec.
For examples: creating a directory if there is none, has the following problems
An exception occurs when the directory didn't exist at the time of exist?
,
but someone else created it before mkdir
was executed.
Subsequent processes are executed without the directory that should be there
when the directory existed at the time of exist?
,
but someone else deleted it shortly afterwards.
Safety:
This cop is unsafe, because autocorrection change to atomic processing. The atomic processing of the replacement destination is not guaranteed to be strictly equivalent to that before the replacement.
Example:
# 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)
Remove unnecessary existence check File.exist?
. Open
File.delete(error_path) if File.exist?(error_path)
- Read upRead up
- Create a ticketCreate a ticket
- Exclude checks
Checks for non-atomic file operation. And then replace it with a nearly equivalent and atomic method.
These can cause problems that are difficult to reproduce, especially in cases of frequent file operations in parallel, such as test runs with parallel_rspec.
For examples: creating a directory if there is none, has the following problems
An exception occurs when the directory didn't exist at the time of exist?
,
but someone else created it before mkdir
was executed.
Subsequent processes are executed without the directory that should be there
when the directory existed at the time of exist?
,
but someone else deleted it shortly afterwards.
Safety:
This cop is unsafe, because autocorrection change to atomic processing. The atomic processing of the replacement destination is not guaranteed to be strictly equivalent to that before the replacement.
Example:
# 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)
Use atomic file operation method FileUtils.mkdir_p
. Open
FileUtils.mkdir(PostgresAdmin.data_directory) unless Dir.exist?(PostgresAdmin.data_directory)
- Read upRead up
- Create a ticketCreate a ticket
- Exclude checks
Checks for non-atomic file operation. And then replace it with a nearly equivalent and atomic method.
These can cause problems that are difficult to reproduce, especially in cases of frequent file operations in parallel, such as test runs with parallel_rspec.
For examples: creating a directory if there is none, has the following problems
An exception occurs when the directory didn't exist at the time of exist?
,
but someone else created it before mkdir
was executed.
Subsequent processes are executed without the directory that should be there
when the directory existed at the time of exist?
,
but someone else deleted it shortly afterwards.
Safety:
This cop is unsafe, because autocorrection change to atomic processing. The atomic processing of the replacement destination is not guaranteed to be strictly equivalent to that before the replacement.
Example:
# 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)
Use atomic file operation method FileUtils.rm_f
. Open
File.delete(error_path) if File.exist?(error_path)
- Read upRead up
- Create a ticketCreate a ticket
- Exclude checks
Checks for non-atomic file operation. And then replace it with a nearly equivalent and atomic method.
These can cause problems that are difficult to reproduce, especially in cases of frequent file operations in parallel, such as test runs with parallel_rspec.
For examples: creating a directory if there is none, has the following problems
An exception occurs when the directory didn't exist at the time of exist?
,
but someone else created it before mkdir
was executed.
Subsequent processes are executed without the directory that should be there
when the directory existed at the time of exist?
,
but someone else deleted it shortly afterwards.
Safety:
This cop is unsafe, because autocorrection change to atomic processing. The atomic processing of the replacement destination is not guaranteed to be strictly equivalent to that before the replacement.
Example:
# 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)