barelyknown/rspec-context-doubles

Temporarily toggle the behavior of doubles for an RSpec example group.

rspec-context-doubles

Temporarily configure RSpec to use a different type of doubles.

Why would you want to do that?

If you use Rails and add a helper method from a controller (or use a gem like canable that does), RSpec will raise an error when one of those helper methods is stubbed in a view spec if it is configured to use verifying doubles.

...or any other situation where you want doubles behavior that is different than the project's configuration.

How do you use it?

Just pass :normal_doubles or :verifying_doubles as metadata to a describe block and you'll temporarily set the behavior for the examples in that block.

# spec_helper.rb
# ...
config.mock_with :rspec do |mocks|
  mocks.verify_partial_doubles = true
end
# ...

# Gemfile
group :test do
  gem "rspec-context-doubles"
end

# example.rb
class Example
  def foo; end
end

# example_spec.rb
describe Example do
  context "configured to use verifying doubles" do
    before(:all) { RSpec::Mocks.configuration.verify_partial_doubles = true }

    describe "temporarily using normal doubles", :normal_doubles do
      it "does not raise an error when a non-existent method is stubbed" do
        expect{allow(subject).to receive(:fo)}.to_not raise_error
      end
    end
    it "raises an error when a non-existent method is stubbed" do
      expect{allow(subject).to receive(:fo)}.to raise_error(RSpec::Mocks::MockExpectationError)
    end
  end

  context "configured to use normal doubles" do
    before(:all) { RSpec::Mocks.configuration.verify_partial_doubles = false }

    describe "temporarily using verifying doubles", :verifying_doubles do
      it "raises an error if a non-existent method is stubbed" do
        expect{allow(subject).to receive(:fo)}.to raise_error(RSpec::Mocks::MockExpectationError)
      end
    end
    it "does not raise an error when a non-existent method is stubbed" do
      expect{allow(subject).to receive(:fo)}.to_not raise_error
    end
  end
end

Credits

Written by @barelyknown.

This gem uses RSpec's shared context feature.

The idea for the gem came from this rspec-mocks issue.