unit-testing - 在测试期间访问由 `beforeAll` 设置的值

Question

这是我所拥有的:

spec :: Spec
spec = do
  manager <- runIO newManager

  it "foo" $ do
    -- code that uses manager

  it "bar" $ do
    -- code that usees manager

runIO 的文档建议我应该使用 beforeAll相反，因为我不需要 manager要构建规范树，我只需要它来运行每个测试，在我的用例中，最好让它们共享同一个管理器，而不是为每个测试创建一个新管理器。

If you do not need the result of the IO action to construct the spec tree, beforeAll may be more suitable for your use case.

beforeAll :: IO a -> SpecWith a -> Spec

但我不知道如何从测试中访问经理。

spec :: Spec
spec = beforeAll newManager go

go :: SpecWith Manager
go = do
  it "foo" $ do
    -- needs "manager" in scope
  it "bar" $ do
    -- needs "manager" in scope

Answer 1

规范参数作为常规函数参数传递给您的 it block (如果您想了解发生了什么，请查看 Example 类型类的关联类型)。一个完全独立的例子是:

import           Test.Hspec

main :: IO ()
main = hspec spec

spec :: Spec
spec = beforeAll (return "foo") $ do
  describe "something" $ do
    it "some behavior" $ \xs -> do
      xs `shouldBe` "foo"

    it "some other behavior" $ \xs -> do
      xs `shouldBe` "foo"