declarative.class_

[Jelleas]

Test classes:

from checkpy import * 

Lexicon = (declarative.class_("Lexicon")
    .params("word_length")
    .method("get_word").params().returnType(str)
)

Hangman = (declarative.class_("Hangman")
    .params("word", "number_of_guesses")
    .method("guess").params("letter").returnType(bool)
    .method("number_of_guesses").params().returnType(int)
    .method("won").params().returnType(bool)
)

Then for checks:

testGuess = test()(Hangman
    .init("hello", 5)
    .method("number_of_guesses").call().returns(5)
    .method("guess").call("a").returns(False)
    .method("number_of_guesses").call().returns(4)
    .method("guess").call("e").returns(True)
    .method("number_of_guesses").call().returns(4)    
)

testWon = passed(testGuess)(Hangman
    .init("a", 1)
    .method("won").call().returns(False)
    .method("guess").call("a").returns(True)
    .method("won").call().returns(True)
)

Mixing with @literal ?

globals_ = {"Hangman": Hangman, "Lexicon": Lexicon}


@literal(globals=globals_)
def testGuess():
     """number of guesses decreases after incorrect guess"""
     hangman = Hangman("hello", 5)
     assert hangman.number_of_guesses() == 5
     assert not hangman.guess("a")
     assert hangman.number_of_guesses() == 4
     assert hangman.guess("e")
     assert hangman.number_of_guesses() == 4

@passed(testGuess)
@literal(globals=globals_)
def testWon():
     """won() returns True after guessing the word"""
     hangman = Hangman("a", 1)
     assert not hangman.won()
     assert hangman.guess("a")
     assert hangman.won()

• isinstance(Hangman, declarative.class_("Hangman")) should return True.

• any attribute access on declarative.class_("Hangman") should be passed on to Hangman

• globals should be inserted before import *, then overwritten after to ensure globals are set on import and not overwritten by the student. Like so:

  globalsCopy = deepcopy(globals)
  exec("from Hangman import *", globals=globals)
  globals.update(globalsCopy)

• name mangling for methods defined on declarative.class_("Hangman") to prevent accidental calls from the student's code???