test against libsnapp

.circleci/config.yml

@@ -20,6 +20,9 @@ common: &common
     - restore_cache:
         keys:
           - cache-{{ .Environment.CIRCLE_JOB }}-{{ checksum "setup.py" }}-{{ checksum "tox.ini" }}
+    - run:
+        name: install libsnappy-dev
+        command: sudo apt install -y libsnappy-dev
     - run:
         name: install dependencies
         command: pip install --user tox

py_snappy/main.py

@@ -159,11 +159,13 @@ def decompress(buf: bytes) -> bytes:
             if length > len(dst) - d or length > src_len - s:
                 raise CorruptError
 
-            dst = list(itertools.chain(  # noqa: E203
-                dst[:d],
-                src[s : s + length],  # noqa: E203
-                dst[d + length :],  # noqa: E203
-            ))
+            dst = list(
+                itertools.chain(  # noqa: E203
+                    dst[:d],
+                    src[s : s + length],  # noqa: E203
+                    dst[d + length :],  # noqa: E203
+                )
+            )
             d += length
             s += length
             continue
@@ -268,7 +270,7 @@ def emit_copy(offset: int, length: int) -> Iterable[int]:
 MAX_TABLE_SIZE = 1 << 14
 
 
-@tuple_gen
+@bytes_gen
 def compress(buf: bytes) -> Iterable[int]:
     """compress returns the compressed form of buf."""
     src = tuple(buf)
@@ -308,12 +310,12 @@ def compress(buf: bytes) -> Iterable[int]:
         t, table[p] = table[p] - 1, s + 1
 
         if (
-                t < 0
-                or s - t >= MAX_OFFSET  # noqa: W503
-                or b0 != src[t]  # noqa: W503
-                or b1 != src[t + 1]  # noqa: W503
-                or b2 != src[t + 2]  # noqa: W503
-                or b3 != src[t + 3]  # noqa: W503
+            t < 0
+            or s - t >= MAX_OFFSET  # noqa: W503
+            or b0 != src[t]  # noqa: W503
+            or b1 != src[t + 1]  # noqa: W503
+            or b2 != src[t + 2]  # noqa: W503
+            or b3 != src[t + 3]  # noqa: W503
         ):
             # If t is invalid or src[s:s+4] differs from src[t:t+4], accumulate a literal byte.
             s += 1

setup.py

@@ -11,6 +11,7 @@
         "pytest-xdist",
         "tox>=2.9.1,<3",
         "hypothesis==3.74.3",
+        "python-snappy>=0.5.3,<1",
     ],
     'lint': [
         "flake8==3.4.1",

tests/test_libsnappy_compat.py

@@ -0,0 +1,22 @@
+from hypothesis import given, settings, strategies as st
+
+from py_snappy import compress, decompress
+from snappy import compress as libsnappy_compress, decompress as libsnappy_decompress
+
+MEGABYTE = 1000000
+
+
+@given(value=st.binary(min_size=1, max_size=2 * MEGABYTE))
+@settings(max_examples=1000)
+def test_local_decompress_libsnappy_compressed(value):
+    intermediate = libsnappy_compress(value)
+    result = decompress(intermediate)
+    assert value == result
+
+
+@given(value=st.binary(min_size=1, max_size=2 * MEGABYTE))
+@settings(max_examples=1000)
+def test_libsnappy_decompress_local_compressed(value):
+    intermediate = compress(value)
+    result = libsnappy_decompress(intermediate)
+    assert value == result