如何防止在基于模型的测试中收缩？

Question

以下是 FsCheck 中基于模型的测试示例：

let spec =
  let inc = { new Command<Counter, int>() with
                    override __.RunActual counter = counter.Inc(); counter
                    override __.RunModel m = m + 1
                    override __.Post(counter, m) = counter.Get = m |@ sprintf "model: %i <> %A" m counter
                    override __.ToString() = "inc" }
                           
  let dec = { new Command<Counter, int>() with
                    override __.RunActual counter = counter.Dec(); counter
                    override __.RunModel m = m - 1
                    override __.Post(counter, m) = counter.Get = m |@ sprintf "model: %i <> %A" m counter
                    override __.ToString() = "dec" }
  
  { new ICommandGenerator<Counter,int> with
      member __.InitialActual = Counter()
      member __.InitialModel = 0
      member __.Next model = Gen.elements [inc;dec] }

如何禁用此测试的命令收缩？

Answer 1

如果你想阻止 FsCheck 缩减使用的命令数量（见我上面的问题），你可以将规范转换为属性禁用缩减：

let property =
    let generator = Command.generate spec
    let shrinker _ = Seq.empty   // disable
    Command.toPropertyWith spec generator shrinker
Check.Quick(property)

这允许 FsCheck 生成比必要的更长的命令序列。例如。 [inc; inc; dec; inc; inc; dec; dec; dec].

如何防止在基于模型的测试中收缩？

How do I prevent shrinking in Model-based testing?

f#

fscheck