README.md
[](https://rubygems.org/gems/type_validator)
[](https://travis-ci.com/serradura/type_validator)
[](https://codeclimate.com/github/serradura/type_validator/maintainability)
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# TypeValidator <!-- omit in toc -->
Adds type validation for classes with [`ActiveModel::Validations >= 3.2`](https://api.rubyonrails.org/classes/ActiveModel/Validations.html).
## Table of Contents <!-- omit in toc -->
- [Required Ruby version](#required-ruby-version)
- [Installation](#installation)
- [Usage](#usage)
- [Default validation](#default-validation)
- [allow_nil option and strict mode](#allow_nil-option-and-strict-mode)
- [Development](#development)
- [Contributing](#contributing)
- [License](#license)
- [Code of Conduct](#code-of-conduct)
## Required Ruby version
> \>= 2.2.0
## Installation
Add this line to your application's Gemfile:
```ruby
gem 'type_validator'
```
And then execute:
$ bundle
Or install it yourself as:
$ gem install type_validator
## Usage
Use any of the type validations below into your models/classes:
**[Object#instance_of?](https://ruby-doc.org/core-2.6.4/Object.html#method-i-instance_of-3F)**
```ruby
validates :name, type: { instance_of: String }
# or use an array to verify if the attribute
# is an instance of one of the classes
validates :name, type: { instance_of: [String, Symbol] }
```
**[Object#kind_of?](https://ruby-doc.org/core-2.6.4/Object.html#method-i-kind_of-3F)**
```ruby
validates :name, type: { is_a: String }
# or
validates :name, type: { kind_of: String }
# Use an array to verify if the attribute
# is an instance of one of the classes
validates :status, type: { is_a: [String, Symbol]}
# or
validates :status, type: { kind_of: [String, Symbol]}
```
**[Object#respond_to?](https://ruby-doc.org/core-2.6.4/Object.html#method-i-respond_to-3F)**
```ruby
validates :handler, type: { respond_to: :call }
```
**Class == Class || Class < Class**
```ruby
# Verifies if the attribute value is the class or a subclass.
validates :handler, type: { klass: Handler }
```
**Array.new.all? { |item| item.is_a?(Class) }**
```ruby
validates :account_types, type: { array_of: String }
# or use an array to verify if the attribute
# is an instance of one of the classes
validates :account_types, type: { array_of: [String, Symbol] }
```
**Array.new.all? { |item| expected_values.include?(item) }**
```ruby
# Verifies if the attribute value
# is an array with some or all the expected values.
validates :account_types, type: { array_with: ['foo', 'bar'] }
```
### Default validation
By default, you can define the attribute type directly (without a hash). e.g.
```ruby
validates :name, type: String
# or
validates :name, type: [String, Symbol]
```
To changes this behavior you can set another strategy to validates the attributes types:
```ruby
TypeValidator.default_validation = :instance_of
# Tip: Create an initializer if you are in a Rails application.
```
And these are the available options to define the default validation:
- `kind_of` *(default)*
- `is_a`
- `instance_of`
### `allow_nil` option and `strict` mode
You can use the `allow_nil` option with any of the type validations. e.g.
```ruby
validates :name, type: { is_a: String }, allow_nil: true
```
And any of the validations work with the`strict: true` option
or with the `validates!` method. e.g.
```ruby
validates :name, type: { is_a: String }, strict: true
#or
validates! :name, type: { is_a: String }
```
## Development
After checking out the repo, run `bin/setup` to install dependencies. Then, run `rake test` 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](https://rubygems.org).
## Contributing
Bug reports and pull requests are welcome on GitHub at https://github.com/serradura/type_validator. This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the [Contributor Covenant](http://contributor-covenant.org) code of conduct.
## License
The gem is available as open source under the terms of the [MIT License](https://opensource.org/licenses/MIT).
## Code of Conduct
Everyone interacting in the TypeValidator project’s codebases, issue trackers, chat rooms and mailing lists is expected to follow the [code of conduct](https://github.com/serradura/type_validator/blob/master/CODE_OF_CONDUCT.md).