How can I create custom matchers in RSpec?

How can I create custom matchers in RSpec?

To create custom matchers in RSpec, you can define a new matcher using the RSpec::Matchers.define method.

Can you give me an example of a custom matcher?

Sure! Here's a simple example:

RSpec::Matchers.define :be_even do
  match do |actual|
    actual.even?
  end
end

You can then use expect(value).to be_even in your tests.

What if I want to add a description to my matcher?

You can add a description by using the description method within your matcher definition. For example:

RSpec::Matchers.define :be_even do
  match do |actual|
    actual.even?
  end

  description do
    "be an even number"
  end
end

How do I test my custom matcher?

You can test your custom matcher just like any other matcher in RSpec. Write a spec that uses it, and RSpec will handle the rest!