class AppTestStringIO: def test_stringio(self): import io sio = io.StringIO() sio.write('Hello ') sio.write('world') assert sio.getvalue() == 'Hello world' assert io.StringIO("hello").read() == 'hello' def test_capabilities(self): import io sio = io.StringIO() assert sio.readable() assert sio.writable() assert sio.seekable() assert not sio.isatty() assert not sio.closed assert not sio.line_buffering sio.close() raises(ValueError, sio.readable) raises(ValueError, sio.writable) raises(ValueError, sio.seekable) raises(ValueError, sio.isatty) assert sio.closed assert sio.errors is None def test_closed(self): import io sio = io.StringIO() sio.close() raises(ValueError, sio.read, 1) raises(ValueError, sio.write, "text") def test_read(self): import io buf = "1234567890" sio = io.StringIO(buf) assert buf[:1] == sio.read(1) assert buf[1:5] == sio.read(4) assert buf[5:] == sio.read(900) assert "" == sio.read() def test_readline(self): import io sio = io.StringIO('123\n456') assert sio.readline(2) == '12' assert sio.readline(None) == '3\n' assert sio.readline() == '456' def test_seek(self): import io s = "1234567890" sio = io.StringIO(s) sio.read(5) sio.seek(0) r = sio.read() assert r == s sio.seek(3) r = sio.read() assert r == s[3:] raises(TypeError, sio.seek, 0.0) exc_info = raises(ValueError, sio.seek, -3) assert exc_info.value.args[0] == "negative seek position: -3" raises(ValueError, sio.seek, 3, -1) raises(ValueError, sio.seek, 3, -3) sio.close() raises(ValueError, sio.seek, 0) def test_overseek(self): import io s = "1234567890" sio = io.StringIO(s) res = sio.seek(11) assert res == 11 res = sio.read() assert res == "" assert sio.tell() == 11 assert sio.getvalue() == s sio.write("") assert sio.getvalue() == s sio.write(s) assert sio.getvalue() == s + "\0" + s def test_tell(self): import io s = "1234567890" sio = io.StringIO(s) assert sio.tell() == 0 sio.seek(5) assert sio.tell() == 5 sio.seek(10000) assert sio.tell() == 10000 sio.close() raises(ValueError, sio.tell) def test_truncate(self): import io s = "1234567890" sio = io.StringIO(s) raises(ValueError, sio.truncate, -1) sio.seek(6) res = sio.truncate() assert res == 6 assert sio.getvalue() == s[:6] res = sio.truncate(4) assert res == 4 assert sio.getvalue() == s[:4] assert sio.tell() == 6 sio.seek(0, 2) sio.write(s) assert sio.getvalue() == s[:4] + s pos = sio.tell() res = sio.truncate(None) assert res == pos assert sio.tell() == pos raises(TypeError, sio.truncate, '0') sio.close() raises(ValueError, sio.truncate, 0) def test_write_error(self): import io exc_info = raises(TypeError, io.StringIO, 3) assert "int" in exc_info.value.args[0] sio = io.StringIO("") exc_info = raises(TypeError, sio.write, 3) assert "int" in exc_info.value.args[0] def test_newline_none(self): import io sio = io.StringIO("a\nb\r\nc\rd", newline=None) res = list(sio) assert res == ["a\n", "b\n", "c\n", "d"] sio.seek(0) res = sio.read(1) assert res == "a" res = sio.read(2) assert res == "\nb" res = sio.read(2) assert res == "\nc" res = sio.read(1) assert res == "\n" sio = io.StringIO(newline=None) res = sio.write("a\n") assert res == 2 res = sio.write("b\r\n") assert res == 3 res = sio.write("c\rd") assert res == 3 sio.seek(0) res = sio.read() assert res == "a\nb\nc\nd" sio = io.StringIO("a\r\nb", newline=None) res = sio.read(3) assert res == "a\nb" def test_newline_empty(self): import io sio = io.StringIO("a\nb\r\nc\rd", newline="") res = list(sio) assert res == ["a\n", "b\r\n", "c\r", "d"] sio.seek(0) res = sio.read(4) assert res == "a\nb\r" res = sio.read(2) assert res == "\nc" res = sio.read(1) assert res == "\r" sio = io.StringIO(newline="") res = sio.write("a\n") assert res == 2 res = sio.write("b\r") assert res == 2 res = sio.write("\nc") assert res == 2 res = sio.write("\rd") assert res == 2 sio.seek(0) res = list(sio) assert res == ["a\n", "b\r\n", "c\r", "d"] def test_newline_lf(self): import io sio = io.StringIO("a\nb\r\nc\rd") res = list(sio) assert res == ["a\n", "b\r\n", "c\rd"] def test_newline_cr(self): import io sio = io.StringIO("a\nb\r\nc\rd", newline="\r") res = sio.read() assert res == "a\rb\r\rc\rd" sio.seek(0) res = list(sio) assert res == ["a\r", "b\r", "\r", "c\r", "d"] def test_newline_crlf(self): import io sio = io.StringIO("a\nb\r\nc\rd", newline="\r\n") res = sio.read() assert res == "a\r\nb\r\r\nc\rd" sio.seek(0) res = list(sio) assert res == ["a\r\n", "b\r\r\n", "c\rd"] def test_newline_property(self): import io sio = io.StringIO(newline=None) assert sio.newlines is None sio.write("a\n") assert sio.newlines == "\n" sio.write("b\r\n") assert sio.newlines == ("\n", "\r\n") sio.write("c\rd") assert sio.newlines == ("\r", "\n", "\r\n") def test_iterator(self): import io s = "1234567890\n" sio = io.StringIO(s * 10) assert iter(sio) is sio assert hasattr(sio, "__iter__") assert hasattr(sio, "__next__") i = 0 for line in sio: assert line == s i += 1 assert i == 10 sio.seek(0) i = 0 for line in sio: assert line == s i += 1 assert i == 10 sio.seek(len(s) * 10 +1) assert list(sio) == [] sio = io.StringIO(s * 2) sio.close() raises(ValueError, next, sio) def test_getstate(self): import io sio = io.StringIO() state = sio.__getstate__() assert len(state) == 4 assert isinstance(state[0], str) assert isinstance(state[1], str) assert isinstance(state[2], int) assert isinstance(state[3], dict) sio.close() raises(ValueError, sio.__getstate__) def test_setstate(self): import io sio = io.StringIO() sio.__setstate__(("no error", "\n", 0, None)) sio.__setstate__(("no error", "", 0, {"spam": 3})) raises(ValueError, sio.__setstate__, ("", "f", 0, None)) raises(ValueError, sio.__setstate__, ("", "", -1, None)) raises(TypeError, sio.__setstate__, (b"", "", 0, None)) raises(TypeError, sio.__setstate__, ("", "", 0.0, None)) raises(TypeError, sio.__setstate__, ("", "", 0, 0)) raises(TypeError, sio.__setstate__, ("len-test", 0)) raises(TypeError, sio.__setstate__) raises(TypeError, sio.__setstate__, 0) sio.close() raises(ValueError, sio.__setstate__, ("closed", "", 0, None))