使用rspec测试易于受到外部影响的代码

Question

I'm using rspec to test a code that may fail depending on the change of a site structure (the external influence I mentioned). I would like to write an example that involves "should raise an error" but I'm not sure if rspec is the right tool to test code in such situations. Could someone point me in some direction?

Thanks in advance

Answer 1

You could write custom matchers

Something like :

site.should_have_valid_structure

Spec::Matchers.define :have_structure
  match do |actual|
    actual.structure == Site::VALID_STRUCTURE
  end
end

Answer 2

Mock the external influence so you can test it properly (if the external influence is a Web page or other HTTP request, WebMock and VCR are great for this). Your tests should not rely on anything external functioning properly -- or improperly. See http://marnen.github.com/webmock-presentation/webmock.html for an overview I wrote last year.