ClojureScript规范断言未触发异常

我有一个实用函数，它使用spec确保传递的map参数完全由整数设置键：

src/project/utils.cljs

(ns project.utils
  (:require [cljs.spec.alpha :as s]))

(defn next-int-key
 "Return the next integer key for a integer keyed map."
 [m]
 (if (empty? m) 0
   (+ 1 (apply max (keys m)))))

(s/fdef next-int-key :args (s/cat :m (s/map-of int? some?)) :ret int?)

(ns project.utils-test
  (:require [project.utils :as utils]
            [cljs.test :refer-macros [deftest testing is]]
            [cljs.spec.alpha :as s]))

(deftest test-next-int-key
  (testing "next-int-key util function"
    (testing "with an empty map"
      (is (= 0 (utils/next-int-key {}))))
    (testing "with a populated, integer keyed map"
      (is (= 4 (utils/next-int-key {0 :zero-val 1 :one-val 2 :two-val 3 :three-val}))))
    (testing "with a populated, integer keyed map that has a gap"
      (is (= 5 (utils/next-int-key {0 :zero-val 1 :one-val 2 :two-val 4 :four-val}))))
    (testing "with a non-integer keyed map"
      (is (= 5 (utils/next-int-key {:one "foo"}))))))

传递非整数键控映射应触发规范断言异常：

test/project/utils\u test.cljs

(ns project.utils
  (:require [cljs.spec.alpha :as s]))

(defn next-int-key
 "Return the next integer key for a integer keyed map."
 [m]
 (if (empty? m) 0
   (+ 1 (apply max (keys m)))))

(s/fdef next-int-key :args (s/cat :m (s/map-of int? some?)) :ret int?)

(ns project.utils-test
  (:require [project.utils :as utils]
            [cljs.test :refer-macros [deftest testing is]]
            [cljs.spec.alpha :as s]))

(deftest test-next-int-key
  (testing "next-int-key util function"
    (testing "with an empty map"
      (is (= 0 (utils/next-int-key {}))))
    (testing "with a populated, integer keyed map"
      (is (= 4 (utils/next-int-key {0 :zero-val 1 :one-val 2 :two-val 3 :three-val}))))
    (testing "with a populated, integer keyed map that has a gap"
      (is (= 5 (utils/next-int-key {0 :zero-val 1 :one-val 2 :two-val 4 :four-val}))))
    (testing "with a non-integer keyed map"
      (is (= 5 (utils/next-int-key {:one "foo"}))))))

但是，不会触发异常，而是允许执行实用程序函数，从而产生错误值。

从Clojure的/CLJS规范文档中，默认情况下启用规范断言

---

我在我的leiningen

项目.clj

中有

：全局变量{*asserts*true}

，尽管我相信这是默认值。

你必须调用

cljs.spec.test.alpha/instrument

才能断言你的spec'd函数的调用。不带参数调用它将检测已加载的每个规范函数：

(stest/instrument)

您可以在测试名称空间中调用它，可以选择传递要插入的特定符号：

(stest/instrument `utils/next-int-key)

更新：未能提及其他一些选项，例如使用

s/valid？

和

:pre

/

:post

断言：

(defn stringer-bell
  "Prints a string and rings bell."
  [s]
  {:pre [(s/valid? (s/nilable string?) s)]}
  (println s "\007"))

或者在函数体中使用

s/assert

（记住

（s/check asserts[true | false]）

切换）：

---

请注意，

s/fdef

是一个开发时工具。为了执行对函数ARGS/结果的约束，考虑使用<代码>：预：POST < /代码>条件，请参见，谢谢，引用<代码>：预和<代码>：POST <代码>真的很有用！谢谢，我重新阅读了clojure.spec指南，我意识到我需要使用

:pre

:post

条件在运行时检查和强制执行spec。