releasetests/utils.py

from contextlib import contextmanager
from datetime import datetime
import random
import shutil
import string
from tempfile import mkdtemp


@contextmanager
def temp_dir():
    dirname = mkdtemp()
    try:
        yield dirname
    finally:
        shutil.rmtree(dirname)


class until_timeout:

    """Yields remaining number of seconds.  Stops when timeout is reached.

    :ivar timeout: Number of seconds to wait.
    """
    def __init__(self, timeout, start=None):
        self.timeout = timeout
        if start is None:
            start = self.now()
        self.start = start

    def __iter__(self):
        return self

    @staticmethod
    def now():
        return datetime.now()

    def next(self):
        elapsed = self.now() - self.start
        remaining = self.timeout - elapsed.total_seconds()
        if remaining <= 0:
            raise StopIteration
        return remaining


def get_random_hex_string(size=64):
    return ''.join(random.choice(string.hexdigits) for n in range(size))


def write_file(path, contents):
    with open(path, 'w') as f:
        f.write(contents)