Writing tests closer to the domain
The other way to make tests easier to read is to write tests in terms of the domain language instead of just the generic functions provided by unittest. In this section, we look at some ways to do this.
Writing helper methods
The first technique is to write helper methods. We employed this technique earlier in this book. The following are some tests that don't use a helper method:
def test_increasing_trend_is_false_if_price_decreases(self):
timestamps = [datetime(2014, 2, 11), datetime(2014, 2, 12),
datetime(2014, 2, 13)]
prices = [8, 12, 10]
for timestamp, price in zip(timestamps, prices):
self.goog.update(timestamp, price)
self.assertFalse(self.goog.is_increasing_trend())
def test_increasing_trend_is_false_if_price_equal(self):
timestamps = [datetime(2014, 2, 11), datetime(2014, 2, 12),
datetime(2014, 2, 13)]
prices = [8, 10, 10]
for timestamp...
