contrib/python-zstandard/tests/test_compressor_fuzzing.py

import io
import os
import unittest

try:
    import hypothesis
    import hypothesis.strategies as strategies
except ImportError:
    raise unittest.SkipTest("hypothesis not available")

import zstandard as zstd

from .common import (
    make_cffi,
    NonClosingBytesIO,
    random_input_data,
    TestCase,
)


@unittest.skipUnless("ZSTD_SLOW_TESTS" in os.environ, "ZSTD_SLOW_TESTS not set")
@make_cffi
class TestCompressor_stream_reader_fuzzing(TestCase):
    @hypothesis.settings(
        suppress_health_check=[hypothesis.HealthCheck.large_base_example]
    )
    @hypothesis.given(
        original=strategies.sampled_from(random_input_data()),
        level=strategies.integers(min_value=1, max_value=5),
        source_read_size=strategies.integers(1, 16384),
        read_size=strategies.integers(-1, zstd.COMPRESSION_RECOMMENDED_OUTPUT_SIZE),
    )
    def test_stream_source_read(self, original, level, source_read_size, read_size):
        if read_size == 0:
            read_size = -1

        refctx = zstd.ZstdCompressor(level=level)
        ref_frame = refctx.compress(original)

        cctx = zstd.ZstdCompressor(level=level)
        with cctx.stream_reader(
            io.BytesIO(original), size=len(original), read_size=source_read_size
        ) as reader:
            chunks = []
            while True:
                chunk = reader.read(read_size)
                if not chunk:
                    break

                chunks.append(chunk)

        self.assertEqual(b"".join(chunks), ref_frame)

    @hypothesis.settings(
        suppress_health_check=[hypothesis.HealthCheck.large_base_example]
    )
    @hypothesis.given(
        original=strategies.sampled_from(random_input_data()),
        level=strategies.integers(min_value=1, max_value=5),
        source_read_size=strategies.integers(1, 16384),
        read_size=strategies.integers(-1, zstd.COMPRESSION_RECOMMENDED_OUTPUT_SIZE),
    )
    def test_buffer_source_read(self, original, level, source_read_size, read_size):
        if read_size == 0:
            read_size = -1

        refctx = zstd.ZstdCompressor(level=level)
        ref_frame = refctx.compress(original)

        cctx = zstd.ZstdCompressor(level=level)
        with cctx.stream_reader(
            original, size=len(original), read_size=source_read_size
        ) as reader:
            chunks = []
            while True:
                chunk = reader.read(read_size)
                if not chunk:
                    break

                chunks.append(chunk)

        self.assertEqual(b"".join(chunks), ref_frame)

    @hypothesis.settings(
        suppress_health_check=[
            hypothesis.HealthCheck.large_base_example,
            hypothesis.HealthCheck.too_slow,
        ]
    )
    @hypothesis.given(
        original=strategies.sampled_from(random_input_data()),
        level=strategies.integers(min_value=1, max_value=5),
        source_read_size=strategies.integers(1, 16384),
        read_sizes=strategies.data(),
    )
    def test_stream_source_read_variance(
        self, original, level, source_read_size, read_sizes
    ):
        refctx = zstd.ZstdCompressor(level=level)
        ref_frame = refctx.compress(original)

        cctx = zstd.ZstdCompressor(level=level)
        with cctx.stream_reader(
            io.BytesIO(original), size=len(original), read_size=source_read_size
        ) as reader:
            chunks = []
            while True:
                read_size = read_sizes.draw(strategies.integers(-1, 16384))
                chunk = reader.read(read_size)
                if not chunk and read_size:
                    break

                chunks.append(chunk)

        self.assertEqual(b"".join(chunks), ref_frame)

    @hypothesis.settings(
        suppress_health_check=[
            hypothesis.HealthCheck.large_base_example,
            hypothesis.HealthCheck.too_slow,
        ]
    )
    @hypothesis.given(
        original=strategies.sampled_from(random_input_data()),
        level=strategies.integers(min_value=1, max_value=5),
        source_read_size=strategies.integers(1, 16384),
        read_sizes=strategies.data(),
    )
    def test_buffer_source_read_variance(
        self, original, level, source_read_size, read_sizes
    ):

        refctx = zstd.ZstdCompressor(level=level)
        ref_frame = refctx.compress(original)

        cctx = zstd.ZstdCompressor(level=level)
        with cctx.stream_reader(
            original, size=len(original), read_size=source_read_size
        ) as reader:
            chunks = []
            while True:
                read_size = read_sizes.draw(strategies.integers(-1, 16384))
                chunk = reader.read(read_size)
                if not chunk and read_size:
                    break

                chunks.append(chunk)

        self.assertEqual(b"".join(chunks), ref_frame)

    @hypothesis.settings(
        suppress_health_check=[hypothesis.HealthCheck.large_base_example]
    )
    @hypothesis.given(
        original=strategies.sampled_from(random_input_data()),
        level=strategies.integers(min_value=1, max_value=5),
        source_read_size=strategies.integers(1, 16384),
        read_size=strategies.integers(1, zstd.COMPRESSION_RECOMMENDED_OUTPUT_SIZE),
    )
    def test_stream_source_readinto(self, original, level, source_read_size, read_size):
        refctx = zstd.ZstdCompressor(level=level)
        ref_frame = refctx.compress(original)

        cctx = zstd.ZstdCompressor(level=level)
        with cctx.stream_reader(
            io.BytesIO(original), size=len(original), read_size=source_read_size
        ) as reader:
            chunks = []
            while True:
                b = bytearray(read_size)
                count = reader.readinto(b)

                if not count:
                    break

                chunks.append(bytes(b[0:count]))

        self.assertEqual(b"".join(chunks), ref_frame)

    @hypothesis.settings(
        suppress_health_check=[hypothesis.HealthCheck.large_base_example]
    )
    @hypothesis.given(
        original=strategies.sampled_from(random_input_data()),
        level=strategies.integers(min_value=1, max_value=5),
        source_read_size=strategies.integers(1, 16384),
        read_size=strategies.integers(1, zstd.COMPRESSION_RECOMMENDED_OUTPUT_SIZE),
    )
    def test_buffer_source_readinto(self, original, level, source_read_size, read_size):

        refctx = zstd.ZstdCompressor(level=level)
        ref_frame = refctx.compress(original)

        cctx = zstd.ZstdCompressor(level=level)
        with cctx.stream_reader(
            original, size=len(original), read_size=source_read_size
        ) as reader:
            chunks = []
            while True:
                b = bytearray(read_size)
                count = reader.readinto(b)

                if not count:
                    break

                chunks.append(bytes(b[0:count]))

        self.assertEqual(b"".join(chunks), ref_frame)

    @hypothesis.settings(
        suppress_health_check=[
            hypothesis.HealthCheck.large_base_example,
            hypothesis.HealthCheck.too_slow,
        ]
    )
    @hypothesis.given(
        original=strategies.sampled_from(random_input_data()),
        level=strategies.integers(min_value=1, max_value=5),
        source_read_size=strategies.integers(1, 16384),
        read_sizes=strategies.data(),
    )
    def test_stream_source_readinto_variance(
        self, original, level, source_read_size, read_sizes
    ):
        refctx = zstd.ZstdCompressor(level=level)
        ref_frame = refctx.compress(original)

        cctx = zstd.ZstdCompressor(level=level)
        with cctx.stream_reader(
            io.BytesIO(original), size=len(original), read_size=source_read_size
        ) as reader:
            chunks = []
            while True:
                read_size = read_sizes.draw(strategies.integers(1, 16384))
                b = bytearray(read_size)
                count = reader.readinto(b)

                if not count:
                    break

                chunks.append(bytes(b[0:count]))

        self.assertEqual(b"".join(chunks), ref_frame)

    @hypothesis.settings(
        suppress_health_check=[
            hypothesis.HealthCheck.large_base_example,
            hypothesis.HealthCheck.too_slow,
        ]
    )
    @hypothesis.given(
        original=strategies.sampled_from(random_input_data()),
        level=strategies.integers(min_value=1, max_value=5),
        source_read_size=strategies.integers(1, 16384),
        read_sizes=strategies.data(),
    )
    def test_buffer_source_readinto_variance(
        self, original, level, source_read_size, read_sizes
    ):

        refctx = zstd.ZstdCompressor(level=level)
        ref_frame = refctx.compress(original)

        cctx = zstd.ZstdCompressor(level=level)
        with cctx.stream_reader(
            original, size=len(original), read_size=source_read_size
        ) as reader:
            chunks = []
            while True:
                read_size = read_sizes.draw(strategies.integers(1, 16384))
                b = bytearray(read_size)
                count = reader.readinto(b)

                if not count:
                    break

                chunks.append(bytes(b[0:count]))

        self.assertEqual(b"".join(chunks), ref_frame)

    @hypothesis.settings(
        suppress_health_check=[hypothesis.HealthCheck.large_base_example]
    )
    @hypothesis.given(
        original=strategies.sampled_from(random_input_data()),
        level=strategies.integers(min_value=1, max_value=5),
        source_read_size=strategies.integers(1, 16384),
        read_size=strategies.integers(-1, zstd.COMPRESSION_RECOMMENDED_OUTPUT_SIZE),
    )
    def test_stream_source_read1(self, original, level, source_read_size, read_size):
        if read_size == 0:
            read_size = -1

        refctx = zstd.ZstdCompressor(level=level)
        ref_frame = refctx.compress(original)

        cctx = zstd.ZstdCompressor(level=level)
        with cctx.stream_reader(
            io.BytesIO(original), size=len(original), read_size=source_read_size
        ) as reader:
            chunks = []
            while True:
                chunk = reader.read1(read_size)
                if not chunk:
                    break

                chunks.append(chunk)

        self.assertEqual(b"".join(chunks), ref_frame)

    @hypothesis.settings(
        suppress_health_check=[hypothesis.HealthCheck.large_base_example]
    )
    @hypothesis.given(
        original=strategies.sampled_from(random_input_data()),
        level=strategies.integers(min_value=1, max_value=5),
        source_read_size=strategies.integers(1, 16384),
        read_size=strategies.integers(-1, zstd.COMPRESSION_RECOMMENDED_OUTPUT_SIZE),
    )
    def test_buffer_source_read1(self, original, level, source_read_size, read_size):
        if read_size == 0:
            read_size = -1

        refctx = zstd.ZstdCompressor(level=level)
        ref_frame = refctx.compress(original)

        cctx = zstd.ZstdCompressor(level=level)
        with cctx.stream_reader(
            original, size=len(original), read_size=source_read_size
        ) as reader:
            chunks = []
            while True:
                chunk = reader.read1(read_size)
                if not chunk:
                    break

                chunks.append(chunk)

        self.assertEqual(b"".join(chunks), ref_frame)

    @hypothesis.settings(
        suppress_health_check=[
            hypothesis.HealthCheck.large_base_example,
            hypothesis.HealthCheck.too_slow,
        ]
    )
    @hypothesis.given(
        original=strategies.sampled_from(random_input_data()),
        level=strategies.integers(min_value=1, max_value=5),
        source_read_size=strategies.integers(1, 16384),
        read_sizes=strategies.data(),
    )
    def test_stream_source_read1_variance(
        self, original, level, source_read_size, read_sizes
    ):
        refctx = zstd.ZstdCompressor(level=level)
        ref_frame = refctx.compress(original)

        cctx = zstd.ZstdCompressor(level=level)
        with cctx.stream_reader(
            io.BytesIO(original), size=len(original), read_size=source_read_size
        ) as reader:
            chunks = []
            while True:
                read_size = read_sizes.draw(strategies.integers(-1, 16384))
                chunk = reader.read1(read_size)
                if not chunk and read_size:
                    break

                chunks.append(chunk)

        self.assertEqual(b"".join(chunks), ref_frame)

    @hypothesis.settings(
        suppress_health_check=[
            hypothesis.HealthCheck.large_base_example,
            hypothesis.HealthCheck.too_slow,
        ]
    )
    @hypothesis.given(
        original=strategies.sampled_from(random_input_data()),
        level=strategies.integers(min_value=1, max_value=5),
        source_read_size=strategies.integers(1, 16384),
        read_sizes=strategies.data(),
    )
    def test_buffer_source_read1_variance(
        self, original, level, source_read_size, read_sizes
    ):

        refctx = zstd.ZstdCompressor(level=level)
        ref_frame = refctx.compress(original)

        cctx = zstd.ZstdCompressor(level=level)
        with cctx.stream_reader(
            original, size=len(original), read_size=source_read_size
        ) as reader:
            chunks = []
            while True:
                read_size = read_sizes.draw(strategies.integers(-1, 16384))
                chunk = reader.read1(read_size)
                if not chunk and read_size:
                    break

                chunks.append(chunk)

        self.assertEqual(b"".join(chunks), ref_frame)

    @hypothesis.settings(
        suppress_health_check=[hypothesis.HealthCheck.large_base_example]
    )
    @hypothesis.given(
        original=strategies.sampled_from(random_input_data()),
        level=strategies.integers(min_value=1, max_value=5),
        source_read_size=strategies.integers(1, 16384),
        read_size=strategies.integers(1, zstd.COMPRESSION_RECOMMENDED_OUTPUT_SIZE),
    )
    def test_stream_source_readinto1(
        self, original, level, source_read_size, read_size
    ):
        if read_size == 0:
            read_size = -1

        refctx = zstd.ZstdCompressor(level=level)
        ref_frame = refctx.compress(original)

        cctx = zstd.ZstdCompressor(level=level)
        with cctx.stream_reader(
            io.BytesIO(original), size=len(original), read_size=source_read_size
        ) as reader:
            chunks = []
            while True:
                b = bytearray(read_size)
                count = reader.readinto1(b)

                if not count:
                    break

                chunks.append(bytes(b[0:count]))

        self.assertEqual(b"".join(chunks), ref_frame)

    @hypothesis.settings(
        suppress_health_check=[hypothesis.HealthCheck.large_base_example]
    )
    @hypothesis.given(
        original=strategies.sampled_from(random_input_data()),
        level=strategies.integers(min_value=1, max_value=5),
        source_read_size=strategies.integers(1, 16384),
        read_size=strategies.integers(1, zstd.COMPRESSION_RECOMMENDED_OUTPUT_SIZE),
    )
    def test_buffer_source_readinto1(
        self, original, level, source_read_size, read_size
    ):
        if read_size == 0:
            read_size = -1

        refctx = zstd.ZstdCompressor(level=level)
        ref_frame = refctx.compress(original)

        cctx = zstd.ZstdCompressor(level=level)
        with cctx.stream_reader(
            original, size=len(original), read_size=source_read_size
        ) as reader:
            chunks = []
            while True:
                b = bytearray(read_size)
                count = reader.readinto1(b)

                if not count:
                    break

                chunks.append(bytes(b[0:count]))

        self.assertEqual(b"".join(chunks), ref_frame)

    @hypothesis.settings(
        suppress_health_check=[
            hypothesis.HealthCheck.large_base_example,
            hypothesis.HealthCheck.too_slow,
        ]
    )
    @hypothesis.given(
        original=strategies.sampled_from(random_input_data()),
        level=strategies.integers(min_value=1, max_value=5),
        source_read_size=strategies.integers(1, 16384),
        read_sizes=strategies.data(),
    )
    def test_stream_source_readinto1_variance(
        self, original, level, source_read_size, read_sizes
    ):
        refctx = zstd.ZstdCompressor(level=level)
        ref_frame = refctx.compress(original)

        cctx = zstd.ZstdCompressor(level=level)
        with cctx.stream_reader(
            io.BytesIO(original), size=len(original), read_size=source_read_size
        ) as reader:
            chunks = []
            while True:
                read_size = read_sizes.draw(strategies.integers(1, 16384))
                b = bytearray(read_size)
                count = reader.readinto1(b)

                if not count:
                    break

                chunks.append(bytes(b[0:count]))

        self.assertEqual(b"".join(chunks), ref_frame)

    @hypothesis.settings(
        suppress_health_check=[
            hypothesis.HealthCheck.large_base_example,
            hypothesis.HealthCheck.too_slow,
        ]
    )
    @hypothesis.given(
        original=strategies.sampled_from(random_input_data()),
        level=strategies.integers(min_value=1, max_value=5),
        source_read_size=strategies.integers(1, 16384),
        read_sizes=strategies.data(),
    )
    def test_buffer_source_readinto1_variance(
        self, original, level, source_read_size, read_sizes
    ):

        refctx = zstd.ZstdCompressor(level=level)
        ref_frame = refctx.compress(original)

        cctx = zstd.ZstdCompressor(level=level)
        with cctx.stream_reader(
            original, size=len(original), read_size=source_read_size
        ) as reader:
            chunks = []
            while True:
                read_size = read_sizes.draw(strategies.integers(1, 16384))
                b = bytearray(read_size)
                count = reader.readinto1(b)

                if not count:
                    break

                chunks.append(bytes(b[0:count]))

        self.assertEqual(b"".join(chunks), ref_frame)


@unittest.skipUnless("ZSTD_SLOW_TESTS" in os.environ, "ZSTD_SLOW_TESTS not set")
@make_cffi
class TestCompressor_stream_writer_fuzzing(TestCase):
    @hypothesis.given(
        original=strategies.sampled_from(random_input_data()),
        level=strategies.integers(min_value=1, max_value=5),
        write_size=strategies.integers(min_value=1, max_value=1048576),
    )
    def test_write_size_variance(self, original, level, write_size):
        refctx = zstd.ZstdCompressor(level=level)
        ref_frame = refctx.compress(original)

        cctx = zstd.ZstdCompressor(level=level)
        b = NonClosingBytesIO()
        with cctx.stream_writer(
            b, size=len(original), write_size=write_size
        ) as compressor:
            compressor.write(original)

        self.assertEqual(b.getvalue(), ref_frame)


@unittest.skipUnless("ZSTD_SLOW_TESTS" in os.environ, "ZSTD_SLOW_TESTS not set")
@make_cffi
class TestCompressor_copy_stream_fuzzing(TestCase):
    @hypothesis.given(
        original=strategies.sampled_from(random_input_data()),
        level=strategies.integers(min_value=1, max_value=5),
        read_size=strategies.integers(min_value=1, max_value=1048576),
        write_size=strategies.integers(min_value=1, max_value=1048576),
    )
    def test_read_write_size_variance(self, original, level, read_size, write_size):
        refctx = zstd.ZstdCompressor(level=level)
        ref_frame = refctx.compress(original)

        cctx = zstd.ZstdCompressor(level=level)
        source = io.BytesIO(original)
        dest = io.BytesIO()

        cctx.copy_stream(
            source, dest, size=len(original), read_size=read_size, write_size=write_size
        )

        self.assertEqual(dest.getvalue(), ref_frame)


@unittest.skipUnless("ZSTD_SLOW_TESTS" in os.environ, "ZSTD_SLOW_TESTS not set")
@make_cffi
class TestCompressor_compressobj_fuzzing(TestCase):
    @hypothesis.settings(
        suppress_health_check=[
            hypothesis.HealthCheck.large_base_example,
            hypothesis.HealthCheck.too_slow,
        ]
    )
    @hypothesis.given(
        original=strategies.sampled_from(random_input_data()),
        level=strategies.integers(min_value=1, max_value=5),
        chunk_sizes=strategies.data(),
    )
    def test_random_input_sizes(self, original, level, chunk_sizes):
        refctx = zstd.ZstdCompressor(level=level)
        ref_frame = refctx.compress(original)

        cctx = zstd.ZstdCompressor(level=level)
        cobj = cctx.compressobj(size=len(original))

        chunks = []
        i = 0
        while True:
            chunk_size = chunk_sizes.draw(strategies.integers(1, 4096))
            source = original[i : i + chunk_size]
            if not source:
                break

            chunks.append(cobj.compress(source))
            i += chunk_size

        chunks.append(cobj.flush())

        self.assertEqual(b"".join(chunks), ref_frame)

    @hypothesis.settings(
        suppress_health_check=[
            hypothesis.HealthCheck.large_base_example,
            hypothesis.HealthCheck.too_slow,
        ]
    )
    @hypothesis.given(
        original=strategies.sampled_from(random_input_data()),
        level=strategies.integers(min_value=1, max_value=5),
        chunk_sizes=strategies.data(),
        flushes=strategies.data(),
    )
    def test_flush_block(self, original, level, chunk_sizes, flushes):
        cctx = zstd.ZstdCompressor(level=level)
        cobj = cctx.compressobj()

        dctx = zstd.ZstdDecompressor()
        dobj = dctx.decompressobj()

        compressed_chunks = []
        decompressed_chunks = []
        i = 0
        while True:
            input_size = chunk_sizes.draw(strategies.integers(1, 4096))
            source = original[i : i + input_size]
            if not source:
                break

            i += input_size

            chunk = cobj.compress(source)
            compressed_chunks.append(chunk)
            decompressed_chunks.append(dobj.decompress(chunk))

            if not flushes.draw(strategies.booleans()):
                continue

            chunk = cobj.flush(zstd.COMPRESSOBJ_FLUSH_BLOCK)
            compressed_chunks.append(chunk)
            decompressed_chunks.append(dobj.decompress(chunk))

            self.assertEqual(b"".join(decompressed_chunks), original[0:i])

        chunk = cobj.flush(zstd.COMPRESSOBJ_FLUSH_FINISH)
        compressed_chunks.append(chunk)
        decompressed_chunks.append(dobj.decompress(chunk))

        self.assertEqual(
            dctx.decompress(b"".join(compressed_chunks), max_output_size=len(original)),
            original,
        )
        self.assertEqual(b"".join(decompressed_chunks), original)


@unittest.skipUnless("ZSTD_SLOW_TESTS" in os.environ, "ZSTD_SLOW_TESTS not set")
@make_cffi
class TestCompressor_read_to_iter_fuzzing(TestCase):
    @hypothesis.given(
        original=strategies.sampled_from(random_input_data()),
        level=strategies.integers(min_value=1, max_value=5),
        read_size=strategies.integers(min_value=1, max_value=4096),
        write_size=strategies.integers(min_value=1, max_value=4096),
    )
    def test_read_write_size_variance(self, original, level, read_size, write_size):
        refcctx = zstd.ZstdCompressor(level=level)
        ref_frame = refcctx.compress(original)

        source = io.BytesIO(original)

        cctx = zstd.ZstdCompressor(level=level)
        chunks = list(
            cctx.read_to_iter(
                source, size=len(original), read_size=read_size, write_size=write_size
            )
        )

        self.assertEqual(b"".join(chunks), ref_frame)


@unittest.skipUnless("ZSTD_SLOW_TESTS" in os.environ, "ZSTD_SLOW_TESTS not set")
class TestCompressor_multi_compress_to_buffer_fuzzing(TestCase):
    @hypothesis.given(
        original=strategies.lists(
            strategies.sampled_from(random_input_data()), min_size=1, max_size=1024
        ),
        threads=strategies.integers(min_value=1, max_value=8),
        use_dict=strategies.booleans(),
    )
    def test_data_equivalence(self, original, threads, use_dict):
        kwargs = {}

        # Use a content dictionary because it is cheap to create.
        if use_dict:
            kwargs["dict_data"] = zstd.ZstdCompressionDict(original[0])

        cctx = zstd.ZstdCompressor(level=1, write_checksum=True, **kwargs)

        if not hasattr(cctx, "multi_compress_to_buffer"):
            self.skipTest("multi_compress_to_buffer not available")

        result = cctx.multi_compress_to_buffer(original, threads=-1)

        self.assertEqual(len(result), len(original))

        # The frame produced via the batch APIs may not be bit identical to that
        # produced by compress() because compression parameters are adjusted
        # from the first input in batch mode. So the only thing we can do is
        # verify the decompressed data matches the input.
        dctx = zstd.ZstdDecompressor(**kwargs)

        for i, frame in enumerate(result):
            self.assertEqual(dctx.decompress(frame), original[i])


@unittest.skipUnless("ZSTD_SLOW_TESTS" in os.environ, "ZSTD_SLOW_TESTS not set")
@make_cffi
class TestCompressor_chunker_fuzzing(TestCase):
    @hypothesis.settings(
        suppress_health_check=[
            hypothesis.HealthCheck.large_base_example,
            hypothesis.HealthCheck.too_slow,
        ]
    )
    @hypothesis.given(
        original=strategies.sampled_from(random_input_data()),
        level=strategies.integers(min_value=1, max_value=5),
        chunk_size=strategies.integers(min_value=1, max_value=32 * 1048576),
        input_sizes=strategies.data(),
    )
    def test_random_input_sizes(self, original, level, chunk_size, input_sizes):
        cctx = zstd.ZstdCompressor(level=level)
        chunker = cctx.chunker(chunk_size=chunk_size)

        chunks = []
        i = 0
        while True:
            input_size = input_sizes.draw(strategies.integers(1, 4096))
            source = original[i : i + input_size]
            if not source:
                break

            chunks.extend(chunker.compress(source))
            i += input_size

        chunks.extend(chunker.finish())

        dctx = zstd.ZstdDecompressor()

        self.assertEqual(
            dctx.decompress(b"".join(chunks), max_output_size=len(original)), original
        )

        self.assertTrue(all(len(chunk) == chunk_size for chunk in chunks[:-1]))

    @hypothesis.settings(
        suppress_health_check=[
            hypothesis.HealthCheck.large_base_example,
            hypothesis.HealthCheck.too_slow,
        ]
    )
    @hypothesis.given(
        original=strategies.sampled_from(random_input_data()),
        level=strategies.integers(min_value=1, max_value=5),
        chunk_size=strategies.integers(min_value=1, max_value=32 * 1048576),
        input_sizes=strategies.data(),
        flushes=strategies.data(),
    )
    def test_flush_block(self, original, level, chunk_size, input_sizes, flushes):
        cctx = zstd.ZstdCompressor(level=level)
        chunker = cctx.chunker(chunk_size=chunk_size)

        dctx = zstd.ZstdDecompressor()
        dobj = dctx.decompressobj()

        compressed_chunks = []
        decompressed_chunks = []
        i = 0
        while True:
            input_size = input_sizes.draw(strategies.integers(1, 4096))
            source = original[i : i + input_size]
            if not source:
                break

            i += input_size

            chunks = list(chunker.compress(source))
            compressed_chunks.extend(chunks)
            decompressed_chunks.append(dobj.decompress(b"".join(chunks)))

            if not flushes.draw(strategies.booleans()):
                continue

            chunks = list(chunker.flush())
            compressed_chunks.extend(chunks)
            decompressed_chunks.append(dobj.decompress(b"".join(chunks)))

            self.assertEqual(b"".join(decompressed_chunks), original[0:i])

        chunks = list(chunker.finish())
        compressed_chunks.extend(chunks)
        decompressed_chunks.append(dobj.decompress(b"".join(chunks)))

        self.assertEqual(
            dctx.decompress(b"".join(compressed_chunks), max_output_size=len(original)),
            original,
        )
        self.assertEqual(b"".join(decompressed_chunks), original)