racket/collects/web-server/tools/send-assertions.ss
2005-05-27 18:56:37 +00:00

166 lines
6.9 KiB
Scheme

;; Drive a servlet. Pretend to be a Web browser, and send a request to the
;; server. Produce the response.
(module send-assertions mzscheme
(require (lib "contract.ss")
(lib "test.ss" "schemeunit")
(lib "etc.ss")
(lib "match.ss")
"servlet-testing-framework.ss"
(lib "servlet.ss" "web-server"))
(provide
assert-output-response/suspended
(struct unknown ())
hyperlink->k-url
form->k-url)
;; The unknown value
(define-struct unknown () (make-inspector))
#|
(define in?
(union
(list-immutable/c (xexpr/callback? . -> . string?)
(listof (cons/c symbol? string?)))
(symbols 'back 'forward)
(list-immutable/c (xexpr/callback? . -> . string?)
(listof (cons/c symbol? string?))
(listof (cons/c symbol? string?)))))
|#
;; Ensure output-response produces the right value. Feed the send/suspends.
;; (-> response) (listof in?) xexpr? . -> . boolean?
(define (assert-output-response/suspended outputter ins out)
(special-equal?
(assert-loop ins (start-servlet outputter) 0 '())
out))
;; A history is a
;; (make-history string? (listof (cons/p symbol? string?))
;; (union #f (listof (cons/p symbol? string?)))
(define-struct history (k-url bindings headers))
;; Go over the input list, resuming the servlet on each choice, until the
;; end. Support the back-button with an indexed list.
;; This is written in a pattern-matching style to increment/decrement the
;; counter correctly, and do any sanity checks (e.g. 'forward after a
;; non-'back).
(define (assert-loop ins r i hs)
(let ((forward-error (make-exn:fail:contract:variable
(string->immutable-string
"Cannot go forward more times than back")
(current-continuation-marks)
'blah)))
(match ins
(('back 'back . ls) (assert-loop (cons 'back ls)
(resumer (list-ref hs (add1 i)))
(add1 i)
hs))
(('back 'forward . ls) (assert-loop (cons 'forward ls)
(resumer (list-ref hs (add1 i)))
(add1 i)
hs))
(('back l . ls) (assert-loop (cons l ls)
(resumer (list-ref hs (add1 i)))
0
(list-tail hs (add1 i))))
(('forward 'back . ls) (if (> i 0)
(assert-loop (cons 'back ls)
(resumer (list-ref hs (sub1 i)))
(sub1 i)
hs)
(raise forward-error)))
(('forward 'forward . ls) (if (> i 0)
(assert-loop (cons 'forward ls)
(resumer (list-ref hs (sub1 i)))
(sub1 i)
hs)
(raise forward-error)))
(('forward l . ls) (if (> i 0)
(assert-loop (cons l ls)
(resumer (list-ref hs (sub1 i)))
0
(list-tail (sub1 i)))
(raise forward-error)))
((l 'back . ls) (let ((h (history/list l r)))
(assert-loop (cons 'back ls)
(resumer h)
0
(cons h hs))))
((l n . ls) (if (and (symbol? n) (symbol=? n 'forward))
(raise forward-error)
(let ((h (history/list l r)))
(assert-loop (cons n ls)
(resumer h)
0
(cons h hs)))))
(('back) (resumer (list-ref hs (add1 i))))
(('forward) (if (> i 0)
(resumer (list-ref hs (sub1 i)))
(raise forward-error)))
((l) (resumer (history/list l r)))
((? null?) r))))
;; history/list : (union (list/p (xexpr? . -> . string?)
;; (listof (cons/p symbol? string?)))
;; (list/p (xexpr? . -> . string?)
;; (listof (cons/p symbol? string?))
;; (listof (cons/p symbol? string?))))
;; response? . -> . history?
(define (history/list l r)
(let ((k-url ((car l) r)))
(if k-url
(cond
((= (length l) 2) (make-history k-url (cadr l) #f))
((= (length l) 3) (make-history k-url (cadr l) (caadr l))))
(fail (format "~a~n~v~n~a~v~n"
"Failed to match the response" r
"with the function" (car l))))))
;; resumer : history? . -> . response?
;; Resume the servlet correctly.
(define (resumer a-history)
(if (history-headers a-history)
(resume-servlet/headers (history-k-url a-history)
(history-bindings a-history)
(history-headers a-history))
(resume-servlet (history-k-url a-history)
(history-bindings a-history))))
;; True if:
;; a or b is `unknown'
;; a and b are not pairs and are equal?
;; a and b are pairs and their car and cdr are special-equal?
(define (special-equal? a b)
(cond
((or (unknown? a) (unknown? b)) #t)
((and (not (pair? a)) (not (pair? b))) (equal? a b))
((and (pair? a) (pair? b)) (and (special-equal? (car a) (car b))
(special-equal? (cdr a) (cdr b))))
(else (equal? a b))))
;; Produce the k-url for the form on this page
(define form->k-url
(match-lambda
((`form ((attrs rhss) ...) . rest)
(ormap (lambda (attr rhs) (and (eqv? attr 'action) rhs))
attrs rhss))
((tag (attrs ...) body ...) (ormap form->k-url body))
(else #f)))
;; Produce the k-url used for the next part of the form
;; (xexpr/callback? . -> . (union false? string?))
(define-syntax hyperlink->k-url
(syntax-rules ()
((_ str)
(letrec ((f (match-lambda
(('a ((attrs rhss) (... ...)) str)
(ormap (lambda (attr rhs) (and (eqv? attr 'href) rhs))
attrs rhss))
((tag (attrs (... ...)) body (... ...)) (ormap f body))
(else #f))))
f))))
)