Doctests

tryke automatically discovers and runs Python doctests alongside your regular tests. No configuration needed.

How discovery works

tryke's static parser scans docstrings for the >>> prompt marker. Any docstring containing interactive examples is collected as a test. This works at every level:

Module-level

"""
Module for math utilities.

>>> add(1, 2)
3
"""

def add(a, b):
    return a + b

Function-level

def greet(name):
    """
    Return a greeting.

    >>> greet("world")
    'hello, world'
    """
    return f"hello, {name}"

Class-level

class Counter:
    """
    A simple counter.

    >>> c = Counter(0)
    >>> c.value
    0
    """

    def __init__(self, value):
        self.value = value

Method-level

class Counter:
    def __init__(self, value):
        self.value = value

    def increment(self):
        """
        Increment the counter by one.

        >>> c = Counter(0)
        >>> c.increment()
        >>> c.value
        1
        """
        self.value += 1

ELLIPSIS support

Doctests run with the ELLIPSIS flag enabled by default. Use ... to match variable output:

def now():
    """
    Return the current timestamp.

    >>> now()  # doctest: +ELLIPSIS
    datetime.datetime(...)
    """
    import datetime
    return datetime.datetime.now()

Running doctests

Doctests are collected automatically with tryke test. They appear in output with a doctest: prefix:

tryke test

You can filter them like any other test:

tryke test -k "doctest"

Static discovery

Like all tryke test discovery, doctests are found by parsing source files — not by importing modules. This means discovery is fast and side-effect free. See test discovery for details.