Python Unittest: Open and wait until the program is closed

Question

Currently I try to create an unit test which opens a file (with the corresponding application) and then the test-run should wait until the program is closed.

Answer 1

You can call the underlying windows APIs, as recommended in this C++ answer, either via pywin32:

def start_file_wait(fname):
    import win32con
    import win32api
    import win32event
    from win32com.shell import shellcon
    from win32com.shell.shell import ShellExecuteEx
    rc = ShellExecuteEx(
        fMask=shellcon.SEE_MASK_NOCLOSEPROCESS,
        nShow=win32con.SW_SHOW,
        lpFile=fname)
    hproc = rc['hProcess']
    win32event.WaitForSingleObject(hproc, win32event.INFINITE)
    win32api.CloseHandle(hproc)

or directly from ctypes:

def startfile_wait(fname):
    import ctypes
    from ctypes.wintypes import ULONG, DWORD, HANDLE, HKEY, HINSTANCE, HWND, LPCWSTR


    class SHELLEXECUTEINFOW(ctypes.Structure):
        _fields_ = [
            ("cbSize", DWORD),
            ("fMask", ULONG),
            ("hwnd", HWND),
            ("lpVerb", LPCWSTR),
            ("lpFile", LPCWSTR),
            ("lpParameters", LPCWSTR),
            ("lpDirectory", LPCWSTR),
            ("nShow", ctypes.c_int),
            ("hInstApp", HINSTANCE),
            ("lpIDList", ctypes.c_void_p),
            ("lpClass", LPCWSTR),
            ("hkeyClass", HKEY),
            ("dwHotKey", DWORD),
            ("DUMMYUNIONNAME", ctypes.c_void_p),
            ("hProcess", HANDLE)
        ]

    shell_execute_ex = ctypes.windll.shell32.ShellExecuteExW
    shell_execute_ex.argtypes = [ctypes.POINTER(SHELLEXECUTEINFOW)]
    shell_execute_ex.res_type = ctypes.c_bool

    wait_for_single_object = ctypes.windll.kernel32.WaitForSingleObject
    wait_for_single_object.argtypes = [HANDLE, DWORD]
    wait_for_single_object.res_type = DWORD

    close_handle = ctypes.windll.kernel32.CloseHandle
    close_handle.argtypes = [HANDLE]
    close_handle.res_type = bool

    # https://stackoverflow.com/a/17638969/102441
    arg = SHELLEXECUTEINFOW()
    arg.cbSize = ctypes.sizeof(arg)
    arg.fMask = 0x00000040  # SEE_MASK_NOCLOSEPROCESS
    arg.hwnd = None
    arg.lpVerb = None
    arg.lpFile = fname
    arg.lpParameters = ""
    arg.lpDirectory = None
    arg.nShow = 10  # SW_SHOWDEFAULT
    arg.hInstApp = None
    ok = shell_execute_ex(arg)
    if not ok:
        raise ctypes.WinError()
    try:
        wait_for_single_object(arg.hProcess, -1)
    finally:
        close_handle(arg.hProcess)