racket/collects/htdp/tests/convert.rkt
2012-08-29 11:35:34 -04:00

68 lines
1.7 KiB
Racket

#lang racket
(require htdp/testing)
(require htdp/convert)
;; f2c : num -> num
;; to convert a Fahrenheit temperature into a Celsius temperature
(define (f2c f)
(* 5/9 (- f 32)))
(define (fx y)
'xyz)
#| Tests: with teach-pack convert.ss |#
(= (f2c 212) 100)
(= (f2c 32) 0)
(= (f2c -40) -40)
;; ----------------------------------------------------------------------------
(define IN "convert-in.dat")
(define OUT "convert-out.dat")
(define (create-convert-in)
(printf "212 32\n-40\n"))
(define (check-convert-out)
(and (= (read) 100)
(= (read) 0)
(= (read) -40)))
(when (file-exists? IN) (delete-file IN))
(with-output-to-file IN create-convert-in)
(when (file-exists? OUT) (delete-file OUT))
(convert-file IN f2c OUT)
(with-input-from-file OUT check-convert-out)
(check-error (convert-file IN list OUT) "convert: The conversion function must produce a number; but it produced '(212)")
(check-error (convert-file IN first OUT) "first: expects non-empty list; given 212")
(check-error (convert-file IN fx OUT) "convert: The conversion function must produce a number; but it produced 'xyz")
(check-error (convert-file IN f2c 10) "convert-file: expects a string as third argument, given 10")
;; ----------------------------------------------------------------------------
;; convert by repl:
(convert-repl f2c)
;; type in 0 212 40 into the repl
;; ----------------------------------------------------------------------------
;; convert by GUI
(convert-gui f2c)
(define (f2x x) (* x x x x))
(convert-gui f2x)
;; must result in an error
;; TEST BY HAND: (convert-gui first)
;; first is blamed but not nicely
;; TEST BY HAND: (convert-gui fx)
;; signal an error about not returning a number
(generate-report)