how to measure sleep duration: test_duration_w_an_earlier_wake_than_sleep_time¶

This is part 3 of a program that calculates the difference between a given wake and sleep time.

I want to test the duration function with a wake_time that is earlier than the sleep_time

red: make it fail ¶

I add a failing test to test_sleep_duration.py with a while statement to make sure wake_time is always earlier than sleep_time

def test_duration_w_an_earlier_wake_than_sleep_time(self):
    sleep_time = random_timestamp()
    wake_time = random_timestamp()
    while wake_time >= sleep_time:
        wake_time = random_timestamp()

    self.assertEqual(
        sleep_duration.duration(
            sleep_time=sleep_time,
            wake_time=wake_time
        ),
        ''
    )

def test_duration_w_hours_and_minutes(self):
...

and get AssertionError

AssertionError: '-1:00' != ''
AssertionError: '-2:12' != ''
AssertionError: '-8:34' != ''
AssertionError: '-10:57' != ''

The duration function returns a negative timestamp when given an earlier wake_time than sleep_time, which is not a real duration. I want it to return a difference when wake_time is later than or the same as sleep_time and raise ValueError with a message when wake_time is earlier than sleep_time. I change the assertEqual to assertRaisesRegex to catch the Exception when it is raised by the function

def test_duration_w_an_earlier_wake_than_sleep_time(self):
    sleep_time = random_timestamp()
    wake_time = random_timestamp()
    while wake_time >= sleep_time:
        wake_time = random_timestamp()

    with self.assertRaisesRegex(
        ValueError,
        f'wake_time: "{wake_time}"'
        ' is earlier than '
        f'sleep_time: "{sleep_time}"'
    ):
        sleep_duration.duration(
            sleep_time=sleep_time,
            wake_time=wake_time
        )

the terminal shows AssertionError

AssertionError: ValueError not raised

I add a condition to the duration function to raise the ValueError

def duration(wake_time=None, sleep_time=None):
    if wake_time < sleep_time:
        raise ValueError(
            f'wake_time: "{wake_time}"'
            ' is earlier than '
            f'sleep_time: "{sleep_time}"'
        )
    else:
        difference_hours = (
            read_timestamp(wake_time)
          - read_timestamp(sleep_time)
        )
        difference_minutes = (
            read_timestamp(wake_time, 1)
          - read_timestamp(sleep_time, 1)
        )

        difference = (
            difference_hours*60
          + difference_minutes
        )

        duration_hours = difference // 60
        duration_minutes = difference % 60

        return (
            f'{duration_hours:02}:'
            f'{duration_minutes:02}'
        )

and the terminal shows a random ValueError for test_duration_w_hours_and_minutes when wake_time is earlier than sleep_time

ValueError: wake_time: "07:33" is earlier than sleep_time: "08:12"
ValueError: wake_time: "07:46" is earlier than sleep_time: "14:47"
ValueError: wake_time: "23:10" is earlier than sleep_time: "23:27"
ValueError: wake_time: "11:32" is earlier than sleep_time: "13:52"

I add the error to the list of Exceptions encountered

# Exceptions Encountered
# AssertionError
# TypeError
# NameError
# AttributeError
# ValueError

then add a while statement to make sure wake_time is not earlier than sleep_time for the difference calculation

def test_duration_w_hours_and_minutes(self):
    sleep_time = random_timestamp()
    wake_time = random_timestamp()
    while wake_time < sleep_time:
        wake_time = random_timestamp()

    difference_hours = (
        int(wake_time.split(':')[0])
      - int(sleep_time.split(':')[0])
    )
    difference_minutes = (
        int(wake_time.split(':')[1])
      - int(sleep_time.split(':')[1])
    )

    difference = (
        difference_hours*60
      + difference_minutes
    )
    duration_hours = difference // 60
    duration_minutes = difference % 60

    self.assertEqual(
        sleep_duration.duration(
            sleep_time=sleep_time,
            wake_time=wake_time
        ),
        (
            f'{duration_hours:02}:'
            f'{duration_minutes:02}'
        )
    )

and the terminal shows passing tests with no more random failures, green, green, green, green all the way!

refactor: make it better ¶

I copy the assertRaisesRegex statement from test_duration_w_an_earlier_wake_than_sleep_time then add it to the while statement to run when wake_time is earlier than sleep_time

def test_duration_w_hours_and_minutes(self):
    sleep_time = random_timestamp()
    wake_time = random_timestamp()

    while wake_time < sleep_time:
        with self.assertRaisesRegex(
            ValueError,
            f'wake_time: "{wake_time}"'
            ' is earlier than '
            f'sleep_time: "{sleep_time}"'
        ):
            sleep_duration.duration(
                sleep_time=sleep_time,
                wake_time=wake_time
            )
        wake_time = random_timestamp()

    difference_hours = (
        int(wake_time.split(':')[0])
      - int(sleep_time.split(':')[0])
    )
    difference_minutes = (
        int(wake_time.split(':')[1])
      - int(sleep_time.split(':')[1])
    )

    difference = (
        difference_hours*60
      + difference_minutes
    )
    duration_hours = difference // 60
    duration_minutes = difference % 60

    self.assertEqual(
        sleep_duration.duration(
            sleep_time=sleep_time,
            wake_time=wake_time
        ),
        (
            f'{duration_hours:02}:'
            f'{duration_minutes:02}'
        )
    )

and comment out the condition in duration to make sure the test still works as expected

def duration(wake_time=None, sleep_time=None):
    # if wake_time < sleep_time:
    #     raise ValueError(
    #         f'wake_time: "{wake_time}"'
    #         ' is earlier than '
    #         f'sleep_time: "{sleep_time}"'
    #     )
    # else:
        difference_hours = (
            read_timestamp(wake_time)
          - read_timestamp(sleep_time)
        )
        difference_minutes = (
            read_timestamp(wake_time, 1)
          - read_timestamp(sleep_time, 1)
        )

        difference = (
            difference_hours*60
          + difference_minutes
        )

        duration_hours = difference // 60
        duration_minutes = difference % 60

        return (
            f'{duration_hours:02}:'
            f'{duration_minutes:02}'
        )

which gives me AssertionError for test_duration_w_an_earlier_wake_than_sleep_time and a random one when wake_time is earlier than sleep_time in test_duration_w_hours_and_minutes

AssertionError: ValueError not raised

the assertRaisesRegex works as expected. I remove the comments and the terminal shows green again

I remove test_duration_w_an_earlier_wake_than_sleep_time because it is now covered by test_duration_w_hours_and_minutes

then add an else block for the rest of the code in test_duration_w_hours_and_minutes

def test_duration_w_hours_and_minutes(self):
    sleep_time = random_timestamp()
    wake_time = random_timestamp()

    while wake_time < sleep_time:
        with self.assertRaisesRegex(
            ValueError,
            f'wake_time: "{wake_time}"'
            ' is earlier than '
            f'sleep_time: "{sleep_time}"'
        ):
            sleep_duration.duration(
                sleep_time=sleep_time,
                wake_time=wake_time
            )
        wake_time = random_timestamp()
    else:
        difference_hours = (
            int(wake_time.split(':')[0])
          - int(sleep_time.split(':')[0])
        )
        difference_minutes = (
            int(wake_time.split(':')[1])
          - int(sleep_time.split(':')[1])
        )

        difference = (
            difference_hours*60
          + difference_minutes
        )
        duration_hours = difference // 60
        duration_minutes = difference % 60

        self.assertEqual(
            sleep_duration.duration(
                sleep_time=sleep_time,
                wake_time=wake_time
            ),
            (
                f'{duration_hours:02}:'
                f'{duration_minutes:02}'
            )
        )

still green

I add a static method to calculate the difference between wake_time and sleep_time

@staticmethod
def get_difference(
    wake_time=None, sleep_time=None
):
    difference_hours = (
        int(wake_time.split(':')[0])
      - int(sleep_time.split(':')[0])
    )
    difference_minutes = (
        int(wake_time.split(':')[1])
      - int(sleep_time.split(':')[1])
    )

    difference = (
        difference_hours*60
        + difference_minutes
    )
    duration_hours = difference // 60
    duration_minutes = difference % 60

    return (
        f'{duration_hours:02}:'
        f'{duration_minutes:02}'
    )

def test_duration_w_hours_and_minutes(self):
...

then call it in test_duration_w_hours_and_minutes to change the expectation

def test_duration_w_hours_and_minutes(self):
    sleep_time = random_timestamp()
    wake_time = random_timestamp()

    while wake_time < sleep_time:
        with self.assertRaisesRegex(
            ValueError,
            f'wake_time: "{wake_time}"'
            ' is earlier than '
            f'sleep_time: "{sleep_time}"'
        ):
            sleep_duration.duration(
                sleep_time=sleep_time,
                wake_time=wake_time
            )
        wake_time = random_timestamp()
    else:
        self.assertEqual(
            sleep_duration.duration(
                sleep_time=sleep_time,
                wake_time=wake_time
            ),
            self.get_difference(
                wake_time=wake_time,
                sleep_time=sleep_time
            )
        )

green again

I also add an assert method for the assertRaisesRegex block

def assertWakeTimeEarlier(
    self, wake_time=None, sleep_time=None
):
    with self.assertRaisesRegex(
        ValueError,
        f'wake_time: "{wake_time}"'
        ' is earlier than '
        f'sleep_time: "{sleep_time}"'
    ):
        sleep_duration.duration(
            sleep_time=sleep_time,
            wake_time=wake_time
        )

@staticmethod
def get_difference(
...

and call it in test_duration_w_hours_and_minutes

def test_duration_w_hours_and_minutes(self):
    sleep_time = random_timestamp()
    wake_time = random_timestamp()

    while wake_time < sleep_time:
        self.assertWakeTimeEarlier(
            wake_time=wake_time,
            sleep_time=sleep_time
        )
        wake_time = random_timestamp()
    else:
        self.assertEqual(
            sleep_duration.duration(
                sleep_time=sleep_time,
                wake_time=wake_time
            ),
            self.get_difference(
                wake_time=wake_time,
                sleep_time=sleep_time
            )
        )

all tests are still passing! Fantastic!

review ¶

The challenge is to write a program that calculates the difference between a given wake and sleep time. I ran the following tests to get something that comes close to doing it

test_string_splitting
test_converting_strings_to_numbers
test_floor_aka_integer_division
test_the_modulo_operation
test_duration_w_hours
test_duration_calculation
test_duration_w_an_earlier_wake_than_sleep_time
test_duration_w_hours_and_minutes where I used a while statement to make sure that when wake_time is earlier than sleep_time the duration function raises ValueError with a message and returns the right difference between the 2 when wake_time is later than or the same as sleep_time

Would you like to test duration with timestamps that have dates?

how to measure sleep duration: tests and solution

how to measure sleep duration: test_duration_w_an_earlier_wake_than_sleep_time¶

red: make it fail¶

green: make it pass¶

refactor: make it better¶

review¶

red: make it fail ¶

green: make it pass ¶

refactor: make it better ¶

review ¶