🗃 tdir - create and fill a temporary directory 🗃

Very convenient for writing tests: you can decorate individual tests or a whole test suite.

tdir() runs code in a temporary directory pre-filled with files: it can either be used as a context manager, or a decorator for functions or classes.

tdir.fill() is a tiny function that recursively fills a directory.

Example: as a context manager

from pathlib import Path
import tdir

cwd = Path.cwd()

# Simplest invocation.

with tdir():
   # Do a lot of things in a temporary directory

# Everything is gone!

# With a single file
with tdir('hello') as td:
    # The file `hello` is there
    assert Path('hello').read_text() = 'hello\n'

    # We're in a temporary directory
    assert td == Path.cwd()
    assert td != cwd

    # Write some other file
    Path('junk.txt').write_text('hello, world\n')

# The temporary directory and the files are gone
assert not td.exists()
assert cwd == Path.cwd()

# A more complex example:
#
with tdir(
    'one.txt',
    three='some information',
    four=Path('existing/file'),  # Copy a file into the tempdir
    sub1={
        'file.txt': 'blank lines\n\n\n\n',
        'sub2': [
            'a', 'b', 'c'
        ]
    },
):
    assert Path('one.txt').exists()
    assert Path('four').read_text() == Path('/existing/file').read_text()
    assert Path('sub1/sub2/a').exists()

# All files gone!

Example: as a decorator

from pathlib import Path
import tdir
import unittest

@tdir
def my_function():
    pass  # my_function() always operates in a temporary directory


# Decorate a TestCase so each test runs in a new temporary directory
# with two files
@tdir('a', foo='bar')
class MyTest(unittest.TestCast):
    def test_something(self):
        assert Path('a').read_text() = 'a\n'

    def test_something_else(self):
        assert Path('foo').read_text() = 'bar\n'


class MyTest2(unittest.TestCast):
    # Decorate just one test in a unitttest
    @tdir(foo='bar', baz=bytes(range(4)))  # binary files are possible
    def test_something(self):
        assert Path('foo').read_text() = 'bar\n'
        assert Path('baz').read_bytes() = bytes(range(4)))

    # Run test in an empty temporary directory
    @tdir
    def test_something_else(self):
        assert not Path('a').exists()
        assert Path().absolute() != self.ORIGINAL_PATH

    ORIGINAL_PATH = Path().absolute()

API Documentation

`fill(_root, *args, **kwargs)`

Recursively fills a directory from file names and optional values.

ARGUMENTS _root: The root directory to fill

args: A list of strings, dictionaries or Paths.

For strings, a file is created with that string as name and contents.

For dictionaries, the contents are used to recursively create and fill
the directory.

For Paths, that file is copied into the target directory under the same
name.

kwargs: A dictionary mapping file or directory names to values.

If the key's value is a string it is used to file a file of that name.

If it's a dictionary, its contents are used to recursively create and
fill a subdirectory.

If it's a Path, that file is copied to the target directory but with
the key as its name.

Source code in tdir/tdir.py

def fill(_root, *args, **kwargs):
    """
    Recursively fills a directory from file names and optional values.

    ARGUMENTS
      _root:
        The root directory to fill

      args:
        A list of strings, dictionaries or Paths.

        For strings, a file is created with that string as name and contents.

        For dictionaries, the contents are used to recursively create and fill
        the directory.

        For Paths, that file is copied into the target directory under the same
        name.

      kwargs:
        A dictionary mapping file or directory names to values.

        If the key's value is a string it is used to file a file of that name.

        If it's a dictionary, its contents are used to recursively create and
        fill a subdirectory.

        If it's a Path, that file is copied to the target directory but with
        the key as its name.
    """
    for a in args:
        if isinstance(a, str):
            a = {a.strip(): a}
        elif isinstance(a, Path):
            a = {a.name: a}
        elif not isinstance(a, dict):
            raise TypeError('Do not understand type %s of %s' % (a, type(a)))
        fill(_root, **a)

    for k, v in kwargs.items():
        rk = Path(_root) / k
        is_dir = isinstance(v, (dict, list, tuple))
        to_make = rk if is_dir else rk.parent
        to_make.mkdir(parents=True, exist_ok=True)

        if isinstance(v, str):
            if not v.endswith('\n'):
                v += '\n'
            rk.write_text(v)

        elif isinstance(v, Path):
            copy = shutil.copytree if v.is_dir() else shutil.copyfile
            copy(str(v), str(rk))

        elif isinstance(v, (bytes, bytearray)):
            rk.write_bytes(v)

        elif isinstance(v, dict):
            fill(rk, **v)

        elif isinstance(v, (list, tuple)):
            fill(rk, *v)

        else:
            raise TypeError('Do not understand type %s=%s' % (k, v))

`tdir(*args, chdir=True, methods=patch.TEST_PREFIX, use_dir='', save=False, clear=False, **kwargs)`

Set up a temporary directory, fill it with files, then tear it down at the end of an operation.

tdir can be used either as a context manager, or a decorator for functions or classes.

ARGUMENTS args, kwargs: Files to put into the temporary directory. See the documentation for tdir.fill()

chdir: If true (the default), change the working directory to the tdir at the start of the operation and restore the original working directory at the end. Otherwise, don't change or restore the working directory.

methods: The methods argument tells how to decorate class methods when decorating a class.

The default decorates only class methods that start with the string
`test` - exactly like `unittest.mock.patch` does.

use_dir: If non-empty, use_dir is used instead of a temp directory (and is not removed at the end) - for example, use_dir='.' puts everything in the current directory.

save: If set to true, the temp directory is not deleted at end and its name is printed to sys.stderr