RspecBeTypeOfMatcher

Rspec matchers for strucural type assertion. Compare values of array to have all expeted_type, hash's key and value are expeted type.

You can use this matcher to asert the actual value have expected type like bellow.

# assert array of Symbol
expect([:foo, :bar]).to be_type_of([Symbol])

# assert hash key and value
expect({ foo: 1, bar: 2 }).to be_type_of({ Symbol => String })

Installation

Add this line to your application's Gemfile:

gem 'rspec_be_type_of_matcher'

And then execute:

$ bundle

Or install it yourself as:

$ gem install rspec_be_type_of_matcher

Usage

Or pattern

ex) assert the value is a String or Symbol

  # rspec build-in matcher
  expect(:foo).to be_kind_of(String).or be_kind_of(Symnbol)

  # ↓
  expect("foo").to be_type_of(String, Symnbol)
  expect(:foo).to be_type_of(String, Symnbol)
  # => ok

  expect(1).to be_type_of(String, Symnbol)
  # => fali

Allow nil value

allow to conain nil value in actual collection.

ex) assert the value is a String or nil

  # rspec built-in matcher
  expect(:foo).to be_nil.or be_kind_of(String)

  # ↓
  expect("foo").to be_type_of(String).or_nil
  expect(nil).to be_type_of(String).or_nil
  # => ok

TrueClass/FalseClass

ex) assert the value is a boolean

  expect(true).to be_type_of(:boolean)
  # => ok

  expect(:foo).to be_type_of(:boolean)
  # => fail

Array pattern

ex) assert the value is a Array of String

  # rspec built-in matcher
  expect(["foo", "bar"]).to all(be_type_of(String))
  # => ok

  # ↓
  expect(["foo", "bar"]).to be_type_of([String])
  # => ok

  expect(["foo", :bar]).to be_type_of([String])
  # => fail

Array pattern must exactly 1 value

  expect(["foo", :bar]).to be_type_of([String, Symbol])
  # => error

ex) assert the value is a Array of (String or Symbol)

  # rspec built-in matcher
  expect(["foo", :bar]).to all(be_kind_of(String).or be_kind_of(Symbol))

  # ↓
  expect(["foo", :bar]).to be_type_of([be_type_of(String, Symbol)])
  # => ok

Hash pattern

ex) assert the value is a Hash those key is Symbol and value is String

  # rspec built-in matcher
  expect({foo: "aaa"}.keys).to all(be_kind_of(Symbol))
  expect({foo: "aaa"}.values).to all(be_kind_of(String))

  # ↓
  expect({foo: "aaa"}).to be_type_of(Symbol => String)
  # => ok

  expect({foo: "aaa", bar: :bbb}).to be_type_of(Symbol => String)
  # => fail

Hash pattern must exactly 1 entry

  expect({foo: "aaa"}).to be_type_of(Symbol => String, Integer => String)
  # => error

with composit matcher on values

  expect({foo: "aaa", bar: 1}).to be_type_of(Symbol => be_type_of(Symbol, Integer))
  # => ok

with composit matcher on key and values

  expect({foo: "aaa", "bar" => 1}).to be_type_of(
    be_type_of(
      be_type_of(String, Symbol) => be_type_of(Symbol, Integer)
    )
  )
  # => ok

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/[USERNAME]/rspec_be_type_of_matcher. This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the Contributor Covenant code of conduct.

License

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

Code of Conduct

Everyone interacting in the RspecBeTypeOfMatcher project’s codebases, issue trackers, chat rooms and mailing lists is expected to follow the code of conduct.