sub_diff

Inspect the changes of your String#sub and String#gsub replacements.

Installation

gem install sub_diff

Requirements

Ruby 1.8.7+

Usage

This gem introduces a couple new methods to String objects.

These methods accept the same arguments as their sub and gsub counterparts.

replaced = 'this is a test'.gsub_diff(/(\S*is)/, 'replaced(\1)') #=> #<DiffCollection:0x007fc532049508>

The difference is that it returns a DiffCollection instead. This object behaves just like a String.

puts replaced #=> "replaced(this) replaced(is) a test"

But it also allows us to check if the replacement actually changed anything.

replaced.changed? #=> true

For a closer look at the changes, we can iterate thru each Diff in the replacment.

replaced.each do |diff|
  puts diff.inspect
end

#=> "replaced(this)"
#=> " "
#=> "replaced(is)"
#=> " a test"

Each Diff object behaves just like a string, but also includes a few additional methods.

replaced.each do |diff|
  puts "    value: #{diff.value.inspect}"
  puts "value_was: #{diff.value_was.inspect}"
  puts " changed?: #{diff.changed?}"
end

#=>     value: "replaced(this)"
#=> value_was: "this"
#=>  changed?: true

#=>     value: " "
#=> value_was: " "
#=>  changed?: false

#=>     value: "replaced(is)"
#=> value_was: "is"
#=>  changed?: true

#=>     value: " a test"
#=> value_was: " a test"
#=>  changed?: false

API

YARD Documentation

Diff#changed?
Diff#value
Diff#value_was
DiffCollection#changed?
DiffCollection#diffs
DiffCollection#each
DiffCollection#size

Testing

bundle exec rspec

Contributing

Fork the project.
Make your feature addition or bug fix.
Add tests for it. This is important so I don't break it in a future version unintentionally.
Commit, do not mess with the version or history.
Send me a pull request. Bonus points for topic branches.