0-add_integer.txt

Doctest for integer sum function
--------------------------------

Import .py module:
    >>> add_integer = __import__('0-add_integer').add_integer

Basic use:
    >>> add_integer(1, 2)
    3

Negative number:
    >>> add_integer(1, -2)
    -1

Float number:
    >>> add_integer(1.4, 2)
    3

String argument a:
    >>> add_integer("1", 2)
    Traceback (most recent call last):
    ...
    TypeError: a must be an integer

String argument b:
    >>> add_integer(1, "2")
    Traceback (most recent call last):
    ...
    TypeError: b must be an integer

Float overflow:
    >>> add_integer(1, float('-inf'))
    Traceback (most recent call last):
    ...
    OverflowError: cannot convert float infinity to integer

Float NaN:
    >>> add_integer(1, float('NaN'))
    Traceback (most recent call last):
    ...
    ValueError: cannot convert float NaN to integer

One argument:
    >>> add_integer(1)
    99

No arguments:
    >>> add_integer(None)
    Traceback (most recent call last):
    ...
    TypeError: a must be an integer