How to use the covimerage.cli function in covimerage

def test_loglevel(mocker, runner, devnull):
    from covimerage import cli

    logger = cli.logger

    m = mocker.patch.object(logger, 'setLevel')

    def assert_output(result):
        if click.__version__ < '7.0':
            assert result.output.splitlines() == [
                'Error: no such option: --nonexistingoption']
        else:
            assert result.output.splitlines() == [
                'Usage: main report [OPTIONS] [PROFILE_FILE]...',
                'Try "main report -h" for help.',
                '',
                'Error: no such option: --nonexistingoption']

    for level in ['error', 'warning', 'info', 'debug']:
        result = runner.invoke(cli.main, [

m = mocker.patch.object(logger, 'setLevel')

    def assert_output(result):
        if click.__version__ < '7.0':
            assert result.output.splitlines() == [
                'Error: no such option: --nonexistingoption']
        else:
            assert result.output.splitlines() == [
                'Usage: main report [OPTIONS] [PROFILE_FILE]...',
                'Try "main report -h" for help.',
                '',
                'Error: no such option: --nonexistingoption']

    for level in ['error', 'warning', 'info', 'debug']:
        result = runner.invoke(cli.main, [
            '--loglevel', level,
            'report', '--nonexistingoption'])
        assert_output(result)
        assert result.exit_code == 2

        level_name = level.upper()
        assert m.call_args_list[-1] == mocker.call(level_name)

    # -v should not override -l.
    m.reset_mock()
    result = runner.invoke(cli.main, [
            '-l', 'warning', '-vvv',
            'report', '--nonexistingoption'])
    assert_output(result)
    assert result.exit_code == 2
    assert m.call_args_list == [mocker.call('WARNING')]

tmpdir.join("foo/bar/test2.vim").ensure().write("echom 2")
        result = runner.invoke(cli.main, ["report", "--source", ".", devnull.name])
        out = result.output.splitlines()
        assert any(l.startswith(fname) for l in out)  # pragma: no branch
        assert out[-1].startswith("TOTAL")
        assert out[-1].endswith(" 0%")
        assert result.exit_code == 0

        result = runner.invoke(cli.main, ["report", devnull.name, "--source", "."])
        out = result.output.splitlines()
        assert any(fname in l for l in out)  # pragma: no branch
        assert out[-1].startswith("TOTAL")
        assert out[-1].endswith(" 0%")
        assert result.exit_code == 0

        result = runner.invoke(cli.main, ["report", "--source", "."])
        out = result.output.splitlines()
        assert out[-1] == "Error: --source can only be used with PROFILE_FILE."
        assert result.exit_code == 2

    result = runner.invoke(
        cli.main,
        [
            "--rcfile",
            devnull.name,
            "report",
            "--source",
            "tests/test_plugin/merged_conditionals.vim",
            "tests/fixtures/merged_conditionals-0.profile",
        ],
    )
    assert (

def test_cli_write_coverage(runner, tmpdir):
    with tmpdir.as_cwd() as old_dir:
        with pytest.raises(SystemExit) as excinfo:
            cli.write_coverage([os.path.join(
                str(old_dir), 'tests/fixtures/conditional_function.profile')])
        assert excinfo.value.code == 0
        assert os.path.exists(DEFAULT_COVERAGE_DATA_FILE)

    result = runner.invoke(cli.main, ['write_coverage', '/does/not/exist'])
    if click.__version__ < '7.0':
        assert result.output.splitlines()[-1].startswith(
            'Error: Invalid value for "profile_file": Could not open file:')
    else:
        assert result.output.splitlines()[-1].startswith(
            'Error: Invalid value for "PROFILE_FILE...": Could not open file:')
    assert result.exit_code == 2

    result = runner.invoke(cli.main, ['write_coverage'])
    if click.__version__ < '7.0':
        expected = 'Error: Missing argument "profile_file".'