scheme - 检查期望函数

Question

;; snoc : X [Listof Any] -> [Listof Any]
;; Adds the X to the end of the list
(define (snoc x l)
  (cond [(empty? l) (cons x empty)]
        [else (cons (first l)
                    (snoc x (rest l)))]))

如上所述，它只是在列表末尾添加一个 X。您将如何为此编写一个简单的检查期望函数？

Answer 1

I'd test the obvious cases, for example:

1. What happens if we add an element to an empty list?
2. What happens if we add an element to a list with one element?
3. What happens if we add an element to a list with two elements?

And so on. For example, the first test would look like this:

(check-expect (snoc 1 '()) '(1))