FlexValidations

Object oriented validations gem with descriptive messages

Installation

Add this line to your application's Gemfile:

gem 'flex_validations'

And then execute:

$ bundle install

Or install it yourself as:

$ gem install flex_validations

Usage

integer.validate(1).success? #=> true
integer.validate("foo").fail? #=> true

case 1
when integer
  puts "This is integer"
when string
  puts "This is string"
end

[1, "1.5", 2, 2.3].select(&integer) #=> [1, 2]

puts integer
#=> value.is_a?(Integer) should succeed

puts integer.validate(1)
#=> 1.is_a?(Integer) succeed

puts integer.validate("foo")
#=> "foo".is_a?(Integer) failed

Simple predicate

positive = FlexValidations::Predicate.new(:positive?)
integer = FlexValidations::Predicate.new(:is_a?, Integer)

string = FlexValidations::Predicate.new(:is_a?, String)
present = FlexValidations::Predicate.new(:present?)

Chain

short = FlexValidations::Chain.new \
          FlexValidations::Call.new(:length),
          FlexValidations::Predicate.new(:<, 256)

And

positive_integer = FlexValidations::And.new(integer, positive)
title = FlexValidations::And.new(string, present, short)

Or

subtitle = FlexValidations::Or.new \
             FlexValidations::Predicate.new(:nil?),
             title

Decoration

have_keys = lambda do |*keys|
  FlexValidations::Chain.new \
    FlexValidations::Call.new(:keys),
    FlexValidations::Decorate.new(Set),
    FlexValidations::Predicate.new(:==, Set.new(keys))
end

hash_of = lambda do |attrs|
  FlexValidations::And.new(
    *attrs.map do |key, validation|
      FlexValidations::Chain.new \
        FlexValidations::Call.new(:[], key),
        validation
    end
  end
end

product =
  FlexValidations::And.new \
    have_keys["id", "title"],
    hash_of[
      "id" => positive_integer,
      "title" => title,
      "subtitle" => subtitle
    ]

Development

After checking out the repo, run bin/setup to install dependencies. Then, run rake spec to run the tests. You can also run bin/console for an interactive prompt that will allow you to experiment.

To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and tags, and push the .gem file to rubygems.org.

Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/DmitryBochkarev/validations.

Authors

• Dmitry Bochkarev - original author
• Korotaev Danil - gem name

License

The gem is available as open source under the terms of the MIT License.