Access the running example

In the context of a custom matcher, you can call helper methods that are available from the current example’s example group. This is used, for example, by rspec-rails in order to wrap rails’ built-in assertions (which depend on helper methods available in the test context).

Call method defined on example from matcher

Given a file named “example_spec.rb” with:

RSpec::Matchers.define :bar do
  match do |_|
    foo == "foo"
  end
end

RSpec.describe "something" do
  def foo
    "foo"
  end

  it "does something" do
    expect("foo").to bar
  end
end

When I run rspec ./example_spec.rb

Then the output should contain “1 example, 0 failures”.

Call method not defined on example from matcher

Given a file named “example_spec.rb” with:

RSpec::Matchers.define :bar do
  match do |_|
    foo == "foo"
  end
end

RSpec.describe "something" do
  it "does something" do
    expect("foo").to bar
  end
end

When I run rspec ./example_spec.rb

Then the output should contain “1 example, 1 failure”

And the output should match /undefined.*method/

And the output should contain “RSpec::Matchers::DSL::Matcher”

And the output should not contain “ExampleGroup”.