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🗃 tdir - create and fill a temporary directory 🗃

Run code inside a temporary directory filled with zero or more files.

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()