ruby-on-rails - 无 rspec 期望的 capybara have_field 在升级到 2.2 时失败

Question

在我将 Capybara 从 2.1.0 升级到 2.2.1 并将 Poltergeist 从 1.4.1 升级到 1.5.0 之后，以下 rspec 期望在我的 Rails 应用程序测试中开始失败:

it{ expect(page).to have_field("foo_field_id", with: nil) }

rspec 错误如下所示:

 Failure/Error: it{ expect(page).to have_field("foo_field_id", with: nil) }
 Capybara::ExpectationNotMet:
   expected to find field "foo_field_id" but there were no matches. Also found "", which matched the selector but not all filters.

如果我抛出一个断点进行检查，则该值确实为零:

»  page.find_field('foo_field_id').value
=> nil

如果我将“with”更改为“text”，则断言通过:

it{ expect(page).to have_field("foo_field_id", text: nil) }

HTML 表单字段如下所示:

<input class="string optional" id="foo_field_id" name="foo[field_id]" type="text">

为什么会这样？

Answer 1

根据 https://github.com/jnicklas/capybara/pull/1169 ，这是因为最近的变化:

It's not possible to match against nil anymore because to_s gets called on what you pass to with.

解决方法是执行以下操作:

expect(find_field("foo_field_id").text).to be_blank