Pytest: monkeypatching time

---

examples/pytest/time-changed/app.py

import time

def now():
    return time.time()

examples/pytest/time-changed/test_impact.py

import app
import time

def test_one():
    our_real_1 = time.time()
    their_real_1 = app.now()
    assert abs(our_real_1 - their_real_1) < 0.00001

    app.time.time = lambda : our_real_1 + 100

    our_real_2 = time.time()
    print (our_real_2 - our_real_1)
    #their_real_2 = app.now()
    #assert abs(our_real_2 - their_real_2) >= 100

examples/pytest/time-changed2/app.py

from time import time

def now():
    return time()

examples/pytest/time-changed2/test_impact.py

import app
import time

def test_one():
    our_real_1 = time.time()
    their_real_1 = app.now()
    assert abs(our_real_1 - their_real_1) < 0.0001

    app.time = lambda : our_real_1 + 100

    our_real_2 = time.time()
    assert abs(our_real_2 - our_real_1) < 0.0001

    their_real_2 = app.now()
    assert abs(our_real_2 - their_real_2) >= 99

def test_two():
    our_real_1 = time.time()
    their_real_1 = app.now()
    assert abs(our_real_1 - their_real_1) < 0.0001

examples/pytest/time-changed2/test_impact_monkeypatch.py

import app
import time

def test_one(monkeypatch):
    our_real_1 = time.time()
    their_real_1 = app.now()
    assert abs(our_real_1 - their_real_1) < 0.0001

    monkeypatch.setattr(app, 'time', lambda : our_real_1 + 100)

    our_real_2 = time.time()
    assert abs(our_real_2 - our_real_1) < 0.0001

    their_real_2 = app.now()
    assert abs(our_real_2 - their_real_2) >= 99

def test_two():
    our_real_1 = time.time()
    their_real_1 = app.now()
    assert abs(our_real_1 - their_real_1) < 0.00001