Matchi

Collection of expectation matchers for Ruby 🤹

Installation

Add this line to your application's Gemfile:

gem "matchi"

And then execute:

$ bundle

Or install it yourself as:

$ gem install matchi

Usage

Built-in matchers

Equivalence matcher:

eql = Matchi::Matcher::Eql.new("foo")
eql.matches? { "foo" } # => true

Identity matcher:

equal = Matchi::Matcher::Equal.new(:foo)
equal.matches? { :foo } # => true

Regular expressions matcher:

match = Matchi::Matcher::Match.new(/^foo$/)
match.matches? { "foo" } # => true

Expecting errors matcher:

raise_exception = Matchi::Matcher::RaiseException.new(NameError)
raise_exception.matches? { Boom } # => true

Truth matcher:

be_true = Matchi::Matcher::BeTrue.new
be_true.matches? { true } # => true

Untruth matcher:

be_false = Matchi::Matcher::BeFalse.new
be_false.matches? { false } # => true

Nil matcher:

be_nil = Matchi::Matcher::BeNil.new
be_nil.matches? { nil } # => true

Custom matchers

Custom matchers can easily be defined for expressing expectations. They can be any Ruby class that responds to matches?, to_s and to_h instance methods.

A Be the answer matcher:

module Matchi
  module Matcher
    class BeTheAnswer < ::Matchi::Matcher::Base
      def matches?
        42.equal?(yield)
      end
    end
  end
end

be_the_answer = Matchi::Matcher::BeTheAnswer.new
be_the_answer.matches? { 42 } # => true

A Be prime matcher:

require "prime"

module Matchi
  module Matcher
    class BePrime < ::Matchi::Matcher::Base
      def matches?
        Prime.prime?(yield)
      end
    end
  end
end

be_prime = Matchi::Matcher::BePrime.new
be_prime.matches? { 42 } # => false

A Start with matcher:

module Matchi
  module Matcher
    class StartWith < ::Matchi::Matcher::Base
      def initialize(expected)
        super()
        @expected = expected
      end

      def matches?
        Regexp.new(/\A#{expected}/).match?(yield)
      end
    end
  end
end

start_with = Matchi::Matcher::StartWith.new("foo")
start_with.matches? { "foobar" } # => true

Contact

• Home page: https://github.com/fixrb/matchi
• Bugs/issues: https://github.com/fixrb/matchi/issues

Versioning

Matchi follows Semantic Versioning 2.0.

License

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

---

This project is sponsored by: