Metadata

ID: ruby-best-practices/file-read

Language: Ruby

Severity: Info

Category: Best Practices

Description

This rule emphasizes the usage of helper functions like File.read or File.binread for reading files in Ruby. Using these functions is a more efficient and safer approach when compared to the traditional method of opening a file, reading its content, and then closing it.

The importance of this rule lies in the fact that it helps prevent common mistakes that can lead to resource leaks. If you use File.open without a block, you must remember to close the file manually. Forgetting to do so can leave the file open indefinitely, which is a waste of system resources. In contrast, helper functions like File.read and File.binread automatically close the file once the content is read, ensuring that resources are properly managed.

To adhere to this rule, always use File.read or File.binread when you need to read the entire contents of a file. Avoid using File.open methods without a block for file reading operations. By following this rule, you will write more efficient, safer, and cleaner code.

Non-Compliant Code Examples

File.open(filename, 'rb').read
File.open(filename, 'rb', &:read)
File.open(filename, 'rb') { |f| f.read }
File.open(filename, 'rb') do |f|
  f.read
end

File.open(filename).read
File.open(filename, &:read)
File.open(filename) { |f| f.read }
File.open(filename) do |f|
  f.read
end
File.open(filename, 'r').read
File.open(filename, 'r', &:read)
File.open(filename, 'r') { |f| f.read }
File.open(filename, 'r') do |f|
  f.read
end

Compliant Code Examples

File.binread(filename)

File.read(filename)

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