[lang-ref] ( build_path ) ( python )

def test_build_path():
    # os.path.join(a, b)

    # A missing separator is inserted automatically.
    assert os.path.join('/path/to'   , 'file1.txt')    == '/path/to/file1.txt'
    assert os.path.join('/path/to/'  , 'file1.txt')    == '/path/to/file1.txt'

    # The result is not normalized.
    assert os.path.join('/path//to'  , 'file1.txt')    == '/path//to/file1.txt'
    assert os.path.join('/path/to//' , 'file1.txt')    == '/path/to//file1.txt'
    assert os.path.join('/path/to/'  , './file1.txt')  == '/path/to/./file1.txt'
    assert os.path.join('/path/to'   , '../file1.txt') == '/path/to/../file1.txt'

    # If an absolute path is given, previous parts are discarded.
    assert os.path.join('/path/to/' , '/file1.txt')    == '/file1.txt'

def test_build_path_alternative():
    # pathlib.Path / joinpath

    # A missing separator is inserted automatically.
    assert (Path('/path/to')   / 'file1.txt').as_posix()   == '/path/to/file1.txt'
    assert (Path('/path/to/')  / 'file1.txt').as_posix()   == '/path/to/file1.txt'

    # Path is partially normalized (e.g., "//" and "./" are collapsed).
    assert (Path('/path//to')  / 'file1.txt').as_posix()   == '/path/to/file1.txt'
    assert (Path('/path/to//') / 'file1.txt').as_posix()   == '/path/to/file1.txt'
    assert (Path('/path/to/')  / './file1.txt').as_posix() == '/path/to/file1.txt'

    # ".." is kept as-is (not resolved) unless you call resolve().
    assert (Path('/path/to') / '../file1.txt').as_posix()  == '/path/to/../file1.txt'

    # If an absolute path is given, previous parts are discarded.
    assert (Path('/path/to') / '/file1.txt').as_posix()   == '/file1.txt'