Webdriver implementation in Chicken Scheme

(define-class <Gecko> (<WebDriver>)
  ((browser #:firefox)
   (server "127.0.0.1")
   (port 4444)))

(define-method (launch (instance <Gecko>) options)
  (let ((pid (process-run "geckodriver > /dev/null 2>&1")))
    (set! (slot-value instance 'browser-pid) pid)
    (set! (slot-value instance 'active?) #t)
    (set! (slot-value instance 'capabilities) options)))

(define-method (construct-capabilities (instance <Gecko>))
  (let ((caps (or (slot-value instance 'capabilities) (list))))
    `((capabilities . ,caps))))

(define-method (postprocess-result (instance <Gecko>) result)
  (alist-ref/default result 'value result))

(define-method (send (instance <WebDriver>) data uri method)
  (let* ((remote (string-append "http://" (slot-value instance 'server) ":" (->string (slot-value instance 'port)) "/"))
         (result (postprocess-result instance
                                     (with-input-from-request
                                      (make-request #:method method
                                                    #:uri (uri-reference (string-append remote uri))
                                                    #:headers (headers `((content-type application/json))))
                                      (if data (json->string data) "")
                                      read-json))))
    (if (and (list? result) (alist-ref/default result 'error #f))
        (wd-throw result)
        result)))

(define-method (send-with-session (instance <WebDriver>) data uri method)
  (send instance data (string-append "session/" (slot-value instance 'session-id) "/" uri) method))

(define-method (initialize-session (instance <WebDriver>))
 (let ((result (send instance (construct-capabilities instance) "session" 'POST)))
   (set! (slot-value instance 'session-id) (alist-ref result 'sessionId))))

(define-method (terminate-session (instance <WebDriver>))
  (when (slot-value instance 'session-id)
    (send instance #f (string-append "session/" (slot-value instance 'session-id)) 'DELETE))
  (set! (slot-value instance 'session-id) #f))

(define-method (set-url (instance <WebDriver>) url)
  (send-with-session instance `((url . ,url)) "url" 'POST))

(define-method (url (instance <WebDriver>))
  (send-with-session instance #f "url" 'GET))

(define-method (back (instance <WebDriver>))
  (send-with-session instance #f "back" 'POST))

(define-method (forward (instance <WebDriver>))
  (send-with-session instance #f "forward" 'POST))

(define-method (refresh (instance <WebDriver>))
  (send-with-session instance #f "refresh" 'POST))

(define-method (title (instance <WebDriver>))
  (send-with-session instance #f "title" 'GET))

(define-method (status (instance <WebDriver>))
  (send-with-session instance #f "status" 'GET))

(define-method (source (instance <WebDriver>))
  (send-with-session instance #f "source" 'GET))

(define-method (screenshot (instance <WebDriver>))
  (base64-decode (send-with-session instance #f "screenshot" 'GET)))

(define-method (print-page (instance <WebDriver>))
  (send-with-session instance #f "print" 'POST))

(define-method (execute-async (instance <WebDriver>) script args)
  (send-with-session instance `((script . ,script) (args . ,args)) "execute/async" 'POST))

(define-method (execute-sync (instance <WebDriver>) script args)
  (send-with-session instance `((script . ,script) (args . ,args)) "execute/sync" 'POST))

(define-class <WDTimeouts> ()
  ((script 30000)
   (pageLoad 300000)
   (implicit 0)))

(define-method (extract (instance <WDTimeouts>))
  `((script . ,(slot-value instance 'script))
    (pageLoad . ,(slot-value instance 'pageLoad))
    (implicit . ,(slot-value instance 'implicit))))

Copyright (C) 2023 Daniel Ziltener

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