import unittest

from reactivex import throw
from reactivex.testing import ReactiveTest, TestScheduler

on_next = ReactiveTest.on_next
on_completed = ReactiveTest.on_completed
on_error = ReactiveTest.on_error
subscribe = ReactiveTest.subscribe
subscribed = ReactiveTest.subscribed
disposed = ReactiveTest.disposed
created = ReactiveTest.created


class RxException(Exception):
    pass


# Helper function for raising exceptions within lambdas
def _raise(ex):
    raise RxException(ex)


class TestThrow(unittest.TestCase):
    def test_throw_exception_basic(self):
        scheduler = TestScheduler()
        ex = "ex"

        def factory():
            return throw(ex)

        results = scheduler.start(factory)
        assert results.messages == [on_error(200, ex)]

    def test_throw_disposed(self):
        scheduler = TestScheduler()

        def factory():
            return throw("ex")

        results = scheduler.start(factory, disposed=200)
        assert results.messages == []

    def test_throw_observer_throws(self):
        scheduler = TestScheduler()
        xs = throw("ex")
        xs.subscribe(
            lambda x: None, lambda ex: _raise("ex"), lambda: None, scheduler=scheduler
        )

        self.assertRaises(RxException, scheduler.start)