Change the reactor temperature to something smiliar but executable

[JensWehner]

For python we replaced the test by this:

# Hint look at monkeypatching for functions
import time
def check_time_to_now_even(seconds):
    """
    Checks whether time difference between now and given time in seconds is even
    """
    if seconds < 0:
        raise ValueError('received negative input')
   
    now=time.time()
    return (seconds-now)%2 == 0

with the solution

#Solution to #4
def test_check_time(monkeypatch):
  def mocktime():
    return 2
  monkeypatch.setattr(time,"time",mocktime)
  assert check_time_to_now_even(0) == 1
  assert check_time_to_now_even(1) == 0

Advantage is people can actually play around with it. The function is quite nonsensical, but we had a better experience with this.

[bast]

Good suggestion to turn it to something executable. Thanks!

Similar idea could be to test the following function without waiting for 4 years:

import datetime

def we_are_in_a_leap_year():
    year = datetime.datetime.now().year
    try:
        # function throws ValueError if the date (Feb 29) does not exist for
        # this year
        datetime.datetime(year, 2, 29)
        return True
    except ValueError:
        return False

[JensWehner]

Yes in the end I do not care, but most students actually wrote tests for this exercise, which was really nice to see how engaged they were. The reactor exercise confused many and we spend a lot of time explaining that this code does not work. So I think the executable code is much better, which exact one you take I do not care. :) Yours is maybe already more relatable and less construed.

[bast]

I agree the reactor one is weird and also full support to replace it.

[JensWehner]

So I make a PR and we merge it or is there any reason that would hold this up?

[bast]

Yes please go ahead with the PR. Thanks a lot for this suggestion. When I taught it, I always just skimmed over it so you have more experience here what works well and what doesn't.

[rantahar]

Am I right in thinking some languages are still missing? I will not merge yet, but we should get back to this.

[JensWehner]

The problem with other languages is, that it it requires a lot of boilerplate to make the test work. Or even Macros, dependency injection or other stuff.