如何在 Clojure 测试中测试预期异常的消息？

Question

我有以下 Clojure 代码：

(defn is-valid-lang
  [lang]
  (.contains (list "ru" "en" "de") lang))

(defn s
  [txt]
  {
   :desc txt
   :lang "ru"
   })

(defn s
  [txt lang]
  (if-not (is-valid-lang lang)
    (throw (.IllegalArgumentException (format "'%s' is an invalid language." lang)))
    {
     :desc txt
     :lang lang
     }
    )
  )

我想编写一个测试来验证s抛出的异常的消息，如果lang无效。

我是这样写的：

(deftest s-lang-invalid-lang-test
  (is
    (thrown-with-msg?
      IllegalArgumentException
      #"'invalid-language' is an invalid language."
      (s "something" "invalid-language")
      )
    )
  )

由于以下错误，测试失败：

error {
 :cause "No matching field found: IllegalArgumentException for class java.lang.String"
 :via
 [{:type java.lang.IllegalArgumentException
   :message "No matching field found: IllegalArgumentException for class java.lang.String"
   :at [clojure.lang.Reflector getInstanceField "Reflector.java" 397]}]
 :trace

如果s抛出带有正确消息的异常，我该如何解决这个问题并确保测试成功？

更新 1：修复了 cfrick 指出的多个 arity 问题。

(defn s
  ([txt]
   {
    :desc txt
    :lang "ru"
    })
  ([txt lang]
   (if-not (is-valid-lang lang)
     (throw (IllegalArgumentException. (format "'%s' is an invalid language." lang)))
     {
      :desc txt
      :lang lang
      })
   )
  )

Answer 1

您没有正确实例化 IllegalArgumentException。Clojure 使用：

(IllegalArgumentException. "your message")

调用Java构造函数。请参阅有关 Java 互操作的这篇文章