view tests/test-cappedreader.py @ 49487:e8481625c582

rust: add Debug constraint to Matcher trait

This makes sure we can easily debug which Matcher we're looking at when using
trait objects, and is just generally useful. Effort to make the debugging
output nicer has been kept to a minimum, please feel free to improve.

import io
import unittest

from mercurial import util


class CappedReaderTests(unittest.TestCase):
    def testreadfull(self):
        source = io.BytesIO(b'x' * 100)

        reader = util.cappedreader(source, 10)
        res = reader.read(10)
        self.assertEqual(res, b'x' * 10)
        self.assertEqual(source.tell(), 10)
        source.seek(0)

        reader = util.cappedreader(source, 15)
        res = reader.read(16)
        self.assertEqual(res, b'x' * 15)
        self.assertEqual(source.tell(), 15)
        source.seek(0)

        reader = util.cappedreader(source, 100)
        res = reader.read(100)
        self.assertEqual(res, b'x' * 100)
        self.assertEqual(source.tell(), 100)
        source.seek(0)

        reader = util.cappedreader(source, 50)
        res = reader.read()
        self.assertEqual(res, b'x' * 50)
        self.assertEqual(source.tell(), 50)
        source.seek(0)

    def testreadnegative(self):
        source = io.BytesIO(b'x' * 100)

        reader = util.cappedreader(source, 20)
        res = reader.read(-1)
        self.assertEqual(res, b'x' * 20)
        self.assertEqual(source.tell(), 20)
        source.seek(0)

        reader = util.cappedreader(source, 100)
        res = reader.read(-1)
        self.assertEqual(res, b'x' * 100)
        self.assertEqual(source.tell(), 100)
        source.seek(0)

    def testreadmultiple(self):
        source = io.BytesIO(b'x' * 100)

        reader = util.cappedreader(source, 10)
        for i in range(10):
            res = reader.read(1)
            self.assertEqual(res, b'x')
            self.assertEqual(source.tell(), i + 1)

        self.assertEqual(source.tell(), 10)
        res = reader.read(1)
        self.assertEqual(res, b'')
        self.assertEqual(source.tell(), 10)
        source.seek(0)

        reader = util.cappedreader(source, 45)
        for i in range(4):
            res = reader.read(10)
            self.assertEqual(res, b'x' * 10)
            self.assertEqual(source.tell(), (i + 1) * 10)

        res = reader.read(10)
        self.assertEqual(res, b'x' * 5)
        self.assertEqual(source.tell(), 45)

    def readlimitpasteof(self):
        source = io.BytesIO(b'x' * 100)

        reader = util.cappedreader(source, 1024)
        res = reader.read(1000)
        self.assertEqual(res, b'x' * 100)
        self.assertEqual(source.tell(), 100)
        res = reader.read(1000)
        self.assertEqual(res, b'')
        self.assertEqual(source.tell(), 100)


if __name__ == '__main__':
    import silenttestrunner

    silenttestrunner.main(__name__)