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How to use TeeStdCapture method in Pytest

Best Python code snippet using pytest

test_capture.py

Source:test_capture.py

...107        in_=capture.SysCapture(0) if in_ else None,108        out=capture.SysCapture(1) if out else None,109        err=capture.SysCapture(2) if err else None,110    )111def TeeStdCapture(112    out: bool = True, err: bool = True, in_: bool = True113) -> MultiCapture[str]:114    return capture.MultiCapture(115        in_=capture.SysCapture(0, tee=True) if in_ else None,116        out=capture.SysCapture(1, tee=True) if out else None,117        err=capture.SysCapture(2, tee=True) if err else None,118    )119@pytest.mark.end_to_end120class TestCaptureManager:121    @pytest.mark.parametrize("method", ["no", "sys", "fd"])122    def test_capturing_basic_api(self, method):123        capouter = StdCaptureFD()124        old = sys.stdout, sys.stderr, sys.stdin125        try:126            capman = CaptureManager(method)127            capman.start_capturing()128            capman.suspend()129            outerr = capman.read()130            assert outerr == ("", "")131            capman.suspend()132            outerr = capman.read()133            assert outerr == ("", "")134            print("hello")135            capman.suspend()136            out, err = capman.read()137            if method == "no":138                assert old == (sys.stdout, sys.stderr, sys.stdin)139            else:140                assert not out141            capman.resume()142            print("hello")143            capman.suspend()144            out, err = capman.read()145            if method != "no":146                assert out == "hello\n"147            capman.stop_capturing()148        finally:149            capouter.stop_capturing()150    def test_init_capturing(self):151        capouter = StdCaptureFD()152        try:153            capman = CaptureManager("fd")154            capman.start_capturing()155            pytest.raises(AssertionError, capman.start_capturing)156            capman.stop_capturing()157        finally:158            capouter.stop_capturing()159@pytest.mark.end_to_end160@pytest.mark.parametrize("method", ["fd", "sys"])161def test_capturing_unicode(tmp_path, runner, method):162    obj = "'b\u00f6y'"163    source = f"""164    # taken from issue 227 from nosetests165    def task_unicode():166        import sys167        print(sys.stdout)168        print({obj})169    """170    tmp_path.joinpath("task_unicode.py").write_text(171        textwrap.dedent(source), encoding="utf-8"172    )173    result = runner.invoke(cli, [tmp_path.as_posix(), f"--capture={method}"])174    assert "1  Succeeded" in result.output175    assert result.exit_code == ExitCode.OK176@pytest.mark.end_to_end177@pytest.mark.parametrize("method", ["fd", "sys"])178def test_capturing_bytes_in_utf8_encoding(tmp_path, runner, method):179    source = """180    def task_unicode():181        print('b\\u00f6y')182    """183    tmp_path.joinpath("task_unicode.py").write_text(184        textwrap.dedent(source), encoding="utf-8"185    )186    result = runner.invoke(cli, [tmp_path.as_posix(), f"--capture={method}"])187    assert "1  Succeeded" in result.output188    assert result.exit_code == ExitCode.OK189@pytest.mark.end_to_end190@pytest.mark.xfail(strict=True, reason="pytask cannot capture during collection.")191def test_collect_capturing(tmp_path, runner):192    source = """193    import sys194    print("collect %s failure" % 13)195    sys.stderr.write("collect %s_stderr failure" % 13)196    import xyz42123197    """198    tmp_path.joinpath("task_module.py").write_text(textwrap.dedent(source))199    result = runner.invoke(cli, [tmp_path.as_posix()])200    for content in [201        "Captured stdout",202        "collect 13 failure",203        "Captured stderr",204        "collect 13_stderr failure",205    ]:206        assert content in result.output207@pytest.mark.end_to_end208def test_capturing_outerr(tmp_path, runner):209    source = """210    import sys211    def task_capturing():212        print(42)213        sys.stderr.write(str(23))214    def task_capturing_error():215        print(1)216        sys.stderr.write(str(2))217        raise ValueError218    """219    tmp_path.joinpath("task_capturing_outerr.py").write_text(textwrap.dedent(source))220    result = runner.invoke(cli, [tmp_path.as_posix()])221    assert "â F" in result.output222    assert "â ." in result.output223    for content in [224        "âââââââââââââââââââââââââââââââââ Failures ââââââââââââââââââââââââââââââââââ",225        "task_capturing_error failed",226        "ValueError",227        "ââââââââââââââââââââââââ Captured stdout during call ââââââââââââââââââââââââ",228        "1",229        "ââââââââââââââââââââââââ Captured stderr during call ââââââââââââââââââââââââ",230        "2",231        "2  Collected tasks",232        "1  Succeeded",233        "1  Failed",234        "âââââââââââ Failed in ",235        "seconds ââââââââ",236    ]:237        assert content in result.output238@pytest.mark.end_to_end239def test_capture_badoutput_issue412(tmp_path, runner):240    source = """241    import os242    def task_func():243        omg = bytearray([1,129,1])244        os.write(1, omg)245        assert 0246    """247    tmp_path.joinpath("task_module.py").write_text(textwrap.dedent(source))248    result = runner.invoke(cli, [tmp_path.as_posix(), "--capture=fd"])249    for content in [250        "task_func",251        "assert 0",252        "Captured",253        "1  Failed",254    ]:255        assert content in result.output256@pytest.mark.unit257class TestCaptureIO:258    def test_text(self):259        f = capture.CaptureIO()260        f.write("hello")261        s = f.getvalue()262        assert s == "hello"263        f.close()264    def test_unicode_and_str_mixture(self):265        f = capture.CaptureIO()266        f.write("\u00f6")267        pytest.raises(TypeError, f.write, b"hello")268    def test_write_bytes_to_buffer(self):269        """In python3, stdout / stderr are text io wrappers (exposing a buffer270        property of the underlying bytestream).  See issue #1407271        """272        f = capture.CaptureIO()273        f.buffer.write(b"foo\r\n")274        assert f.getvalue() == "foo\r\n"275@pytest.mark.unit276class TestTeeCaptureIO(TestCaptureIO):277    def test_text(self):278        sio = io.StringIO()279        f = capture.TeeCaptureIO(sio)280        f.write("hello")281        s1 = f.getvalue()282        assert s1 == "hello"283        s2 = sio.getvalue()284        assert s2 == s1285        f.close()286        sio.close()287    def test_unicode_and_str_mixture(self):288        sio = io.StringIO()289        f = capture.TeeCaptureIO(sio)290        f.write("\u00f6")291        pytest.raises(TypeError, f.write, b"hello")292@pytest.mark.integration293def test_dontreadfrominput():294    from _pytest.capture import DontReadFromInput295    f = DontReadFromInput()296    assert f.buffer is f297    assert not f.isatty()298    pytest.raises(OSError, f.read)299    pytest.raises(OSError, f.readlines)300    iter_f = iter(f)301    pytest.raises(OSError, next, iter_f)302    pytest.raises(UnsupportedOperation, f.fileno)303    f.close()  # just for completeness304@pytest.mark.unit305def test_captureresult() -> None:306    cr = CaptureResult("out", "err")307    assert len(cr) == 2308    assert cr.out == "out"309    assert cr.err == "err"310    out, err = cr311    assert out == "out"312    assert err == "err"313    assert cr[0] == "out"314    assert cr[1] == "err"315    assert cr == cr316    assert cr == CaptureResult("out", "err")317    assert cr != CaptureResult("wrong", "err")318    assert cr == ("out", "err")319    assert cr != ("out", "wrong")320    assert hash(cr) == hash(CaptureResult("out", "err"))321    assert hash(cr) == hash(("out", "err"))322    assert hash(cr) != hash(("out", "wrong"))323    assert cr < ("z",)324    assert cr < ("z", "b")325    assert cr < ("z", "b", "c")326    assert cr.count("err") == 1327    assert cr.count("wrong") == 0328    assert cr.index("err") == 1329    with pytest.raises(ValueError):330        assert cr.index("wrong") == 0331    assert next(iter(cr)) == "out"332    assert cr._replace(err="replaced") == ("out", "replaced")333@pytest.fixture()334def tmpfile(tmp_path) -> Generator[BinaryIO, None, None]:335    f = tmp_path.joinpath("task_module.py").open("wb+")336    yield f337    if not f.closed:338        f.close()339@contextlib.contextmanager340def lsof_check():341    pid = os.getpid()342    try:343        out = subprocess.check_output(("lsof", "-p", str(pid))).decode()344    except (OSError, subprocess.CalledProcessError, UnicodeDecodeError) as exc:345        # about UnicodeDecodeError, see note on pytester346        pytest.skip(f"could not run 'lsof' ({exc!r})")347    yield348    out2 = subprocess.check_output(("lsof", "-p", str(pid))).decode()349    len1 = len([x for x in out.split("\n") if "REG" in x])350    len2 = len([x for x in out2.split("\n") if "REG" in x])351    assert len2 < len1 + 3, out2352@pytest.mark.unit353class TestFDCapture:354    def test_simple(self, tmpfile):355        fd = tmpfile.fileno()356        cap = capture.FDCapture(fd)357        data = b"hello"358        os.write(fd, data)359        pytest.raises(AssertionError, cap.snap)360        cap.done()361        cap = capture.FDCapture(fd)362        cap.start()363        os.write(fd, data)364        s = cap.snap()365        cap.done()366        assert s == "hello"367    def test_simple_many(self, tmpfile):368        for _ in range(10):369            self.test_simple(tmpfile)370    def test_simple_many_check_open_files(self, tmp_path):371        with lsof_check():372            with tmp_path.joinpath("task_module.py").open("wb+") as tmpfile:373                self.test_simple_many(tmpfile)374    def test_simple_fail_second_start(self, tmpfile):375        fd = tmpfile.fileno()376        cap = capture.FDCapture(fd)377        cap.done()378        pytest.raises(AssertionError, cap.start)379    def test_stderr(self):380        cap = capture.FDCapture(2)381        cap.start()382        print("hello", file=sys.stderr)383        s = cap.snap()384        cap.done()385        assert s == "hello\n"386    def test_stdin(self):387        cap = capture.FDCapture(0)388        cap.start()389        x = os.read(0, 100).strip()390        cap.done()391        assert x == b""392    def test_writeorg(self, tmpfile):393        data1, data2 = b"foo", b"bar"394        cap = capture.FDCapture(tmpfile.fileno())395        cap.start()396        tmpfile.write(data1)397        tmpfile.flush()398        cap.writeorg(data2.decode("ascii"))399        scap = cap.snap()400        cap.done()401        assert scap == data1.decode("ascii")402        with open(tmpfile.name, "rb") as stmp_file:403            stmp = stmp_file.read()404            assert stmp == data2405    def test_simple_resume_suspend(self):406        with saved_fd(1):407            cap = capture.FDCapture(1)408            cap.start()409            data = b"hello"410            os.write(1, data)411            sys.stdout.write("whatever")412            s = cap.snap()413            assert s == "hellowhatever"414            cap.suspend()415            os.write(1, b"world")416            sys.stdout.write("qlwkej")417            assert not cap.snap()418            cap.resume()419            os.write(1, b"but now")420            sys.stdout.write(" yes\n")421            s = cap.snap()422            assert s == "but now yes\n"423            cap.suspend()424            cap.done()425            pytest.raises(AssertionError, cap.suspend)426            assert repr(cap) == (427                "<FDCapture 1 oldfd={} _state='done' tmpfile={!r}>".format(428                    cap.targetfd_save, cap.tmpfile429                )430            )431            # Should not crash with missing "_old".432            assert repr(cap.syscapture) == (433                "<SysCapture stdout _old=<UNSET> _state='done' tmpfile={!r}>".format(434                    cap.syscapture.tmpfile435                )436            )437    def test_capfd_sys_stdout_mode(self, capfd):  # noqa: U100438        assert "b" not in sys.stdout.mode439@contextlib.contextmanager440def saved_fd(fd):441    new_fd = os.dup(fd)442    try:443        yield444    finally:445        os.dup2(new_fd, fd)446        os.close(new_fd)447@pytest.mark.unit448class TestStdCapture:449    captureclass = staticmethod(StdCapture)450    @contextlib.contextmanager451    def getcapture(self, **kw):452        cap = self.__class__.captureclass(**kw)453        cap.start_capturing()454        try:455            yield cap456        finally:457            cap.stop_capturing()458    def test_capturing_done_simple(self):459        with self.getcapture() as cap:460            sys.stdout.write("hello")461            sys.stderr.write("world")462            out, err = cap.readouterr()463        assert out == "hello"464        assert err == "world"465    def test_capturing_reset_simple(self):466        with self.getcapture() as cap:467            print("hello world")468            sys.stderr.write("hello error\n")469            out, err = cap.readouterr()470        assert out == "hello world\n"471        assert err == "hello error\n"472    def test_capturing_readouterr(self):473        with self.getcapture() as cap:474            print("hello world")475            sys.stderr.write("hello error\n")476            out, err = cap.readouterr()477            assert out == "hello world\n"478            assert err == "hello error\n"479            sys.stderr.write("error2")480            out, err = cap.readouterr()481        assert err == "error2"482    def test_capture_results_accessible_by_attribute(self):483        with self.getcapture() as cap:484            sys.stdout.write("hello")485            sys.stderr.write("world")486            capture_result = cap.readouterr()487        assert capture_result.out == "hello"488        assert capture_result.err == "world"489    def test_capturing_readouterr_unicode(self):490        with self.getcapture() as cap:491            print("hxÄÄ")492            out, err = cap.readouterr()493        assert out == "hxÄÄ\n"494    def test_reset_twice_error(self):495        with self.getcapture() as cap:496            print("hello")497            out, err = cap.readouterr()498        pytest.raises(ValueError, cap.stop_capturing)499        assert out == "hello\n"500        assert not err501    def test_capturing_modify_sysouterr_in_between(self):502        oldout = sys.stdout503        olderr = sys.stderr504        with self.getcapture() as cap:505            sys.stdout.write("hello")506            sys.stderr.write("world")507            sys.stdout = capture.CaptureIO()508            sys.stderr = capture.CaptureIO()509            print("not seen")510            sys.stderr.write("not seen\n")511            out, err = cap.readouterr()512        assert out == "hello"513        assert err == "world"514        assert sys.stdout == oldout515        assert sys.stderr == olderr516    def test_capturing_error_recursive(self):517        with self.getcapture() as cap1:518            print("cap1")519            with self.getcapture() as cap2:520                print("cap2")521                out2, err2 = cap2.readouterr()522                out1, err1 = cap1.readouterr()523        assert out1 == "cap1\n"524        assert out2 == "cap2\n"525    def test_just_out_capture(self):526        with self.getcapture(out=True, err=False) as cap:527            sys.stdout.write("hello")528            sys.stderr.write("world")529            out, err = cap.readouterr()530        assert out == "hello"531        assert not err532    def test_just_err_capture(self):533        with self.getcapture(out=False, err=True) as cap:534            sys.stdout.write("hello")535            sys.stderr.write("world")536            out, err = cap.readouterr()537        assert err == "world"538        assert not out539    def test_stdin_restored(self):540        old = sys.stdin541        with self.getcapture(in_=True):542            newstdin = sys.stdin543        assert newstdin != sys.stdin544        assert sys.stdin is old545    def test_stdin_nulled_by_default(self):546        print("XXX this test may well hang instead of crashing")547        print("XXX which indicates an error in the underlying capturing")548        print("XXX mechanisms")549        with self.getcapture():550            pytest.raises(OSError, sys.stdin.read)551@pytest.mark.unit552class TestTeeStdCapture(TestStdCapture):553    captureclass = staticmethod(TeeStdCapture)554    def test_capturing_error_recursive(self):555        r"""For TeeStdCapture since we passthrough stderr/stdout, cap1556        should get all output, while cap2 should only get "cap2\n"."""557        with self.getcapture() as cap1:558            print("cap1")559            with self.getcapture() as cap2:560                print("cap2")561                out2, err2 = cap2.readouterr()562                out1, err1 = cap1.readouterr()563        assert out1 == "cap1\ncap2\n"564        assert out2 == "cap2\n"565@pytest.mark.unit566class TestStdCaptureFD(TestStdCapture):...

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