(.require
 [library
  [lux (.except)
   ["_" test (.only Test)]
   [abstract
    [monad (.only do)]]
   [control
    ["[0]" io]
    ["[0]" try (.only Try)]
    ["[0]" exception (.only exception:)]]
   [data
    ["[0]" text (.use "[1]#[0]" equivalence)
     ["%" \\format (.only format)]]]
   [math
    ["[0]" random]]]]
 [\\library
  ["[0]" /]]
 [\\specification
  ["$[0]" /]])

(exception: dead)

(def mock
  (/.Mock [Bit Text])
  (implementation
   (def (on_read [dead? content])
     (do try.monad
       [char (try.of_maybe (text.char 0 content))
        [_ content] (try.of_maybe (text.split_at 1 content))]
       (if dead?
         (exception.except ..dead [])
         (in [[dead? content] char]))))

   (def (on_read_line [dead? content])
     (do try.monad
       [[line content] (try.of_maybe (text.split_by text.new_line content))]
       (if dead?
         (exception.except ..dead [])
         (in [[dead? content] line]))))

   (def (on_write message [dead? content])
     (if dead?
       (exception.except ..dead [])
       {try.#Success [dead? (format content message)]}))

   (def (on_close [dead? content])
     (if dead?
       (exception.except ..dead [])
       {try.#Success [true content]}))))

(def .public test
  Test
  (<| (_.covering /._)
      (all _.and
           (_.for [/.async /.mock /.Mock]
                  ($/.spec (io.io (/.async (/.mock ..mock [false ""])))))
           (do random.monad
             [expected (random.alphabetic 10)
              .let [console (/.mock ..mock [false ""])]]
             (_.coverage [/.write_line]
               (io.run!
                (do io.monad
                  [?_ (/.write_line expected console)
                   ?actual (at console read_line [])]
                  (in (<| (try.else false)
                          (do try.monad
                            [_ ?_
                             actual ?actual]
                            (in (text#= expected actual)))))))))
           )))