Python: Add unit tests for brotli.compress and brotli.decompress (#467)

Also
  - rename `test_utils` to `_test_utils`
  - refactor shared code into `_test_utils`

8 files changed, 282 insertions, 119 deletions

diff --git a/python/tests/_test_utils.py b/python/tests/_test_utils.py
new file mode 100644
index 0000000..ad48210
--- /dev/null
+++ b/python/tests/_test_utils.py
@@ -0,0 +1,100 @@
+from __future__ import print_function
+import filecmp
+import glob
+import os
+import sys
+import sysconfig
+import unittest
+
+
+def diff_q(first_file, second_file):
+    """Simulate call to POSIX diff with -q argument"""
+    if not filecmp.cmp(first_file, second_file, shallow=False):
+        print(
+            'Files %s and %s differ' % (first_file, second_file),
+            file=sys.stderr)
+        return 1
+    return 0
+
+
+project_dir = os.path.abspath(os.path.join(__file__, '..', '..', '..'))
+
+PYTHON = sys.executable or 'python'
+
+BRO = os.path.join(project_dir, 'python', 'bro.py')
+
+# Get the platform/version-specific build folder.
+# By default, the distutils build base is in the same location as setup.py.
+platform_lib_name = 'lib.{platform}-{version[0]}.{version[1]}'.format(
+    platform=sysconfig.get_platform(), version=sys.version_info)
+build_dir = os.path.join(project_dir, 'bin', platform_lib_name)
+
+# Prepend the build folder to sys.path and the PYTHONPATH environment variable.
+if build_dir not in sys.path:
+    sys.path.insert(0, build_dir)
+TEST_ENV = os.environ.copy()
+if 'PYTHONPATH' not in TEST_ENV:
+    TEST_ENV['PYTHONPATH'] = build_dir
+else:
+    TEST_ENV['PYTHONPATH'] = build_dir + os.pathsep + TEST_ENV['PYTHONPATH']
+
+TESTDATA_DIR = os.path.join(project_dir, 'tests', 'testdata')
+
+TESTDATA_FILES = [
+    'empty',  # Empty file
+    '10x10y',  # Small text
+    'alice29.txt',  # Large text
+    'random_org_10k.bin',  # Small data
+    'mapsdatazrh',  # Large data
+]
+
+TESTDATA_PATHS = [os.path.join(TESTDATA_DIR, f) for f in TESTDATA_FILES]
+
+TESTDATA_PATHS_FOR_DECOMPRESSION = glob.glob(
+    os.path.join(TESTDATA_DIR, '*.compressed'))
+
+
+def get_temp_compressed_name(filename):
+    return filename + '.bro'
+
+
+def get_temp_uncompressed_name(filename):
+    return filename + '.unbro'
+
+
+def bind_method_args(method, *args):
+    return lambda self: method(self, *args)
+
+
+def generate_test_methods(test_case_class, for_decompression=False):
+    # Add test methods for each test data file.  This makes identifying problems
+    # with specific compression scenarios easier.
+    if for_decompression:
+        paths = TESTDATA_PATHS_FOR_DECOMPRESSION
+    else:
+        paths = TESTDATA_PATHS
+    for method in [m for m in dir(test_case_class) if m.startswith('_test')]:
+        for testdata in paths:
+            f = os.path.splitext(os.path.basename(testdata))[0]
+            name = 'test_{method}_{file}'.format(method=method, file=f)
+            func = bind_method_args(getattr(test_case_class, method), testdata)
+            setattr(test_case_class, name, func)
+
+
+class TestCase(unittest.TestCase):
+
+    def tearDown(self):
+        for f in TESTDATA_PATHS:
+            try:
+                os.unlink(get_temp_compressed_name(f))
+            except OSError:
+                pass
+            try:
+                os.unlink(get_temp_uncompressed_name(f))
+            except OSError:
+                pass
+
+    def assertFilesMatch(self, first, second):
+        self.assertTrue(
+            filecmp.cmp(first, second, shallow=False),
+            'File {} differs from {}'.format(first, second))
diff --git a/python/tests/compatibility_test.py b/python/tests/compatibility_test.py
index b6dbf77..d6e5151 100755..100644
--- a/python/tests/compatibility_test.py
+++ b/python/tests/compatibility_test.py
@@ -5,7 +5,7 @@ import sys
 import os
 from subprocess import check_call
 
-from test_utils import PYTHON, BRO, TEST_ENV, diff_q
+from _test_utils import PYTHON, BRO, TEST_ENV, diff_q
 
 
 os.chdir(os.path.abspath("../../tests"))
diff --git a/python/tests/compress_test.py b/python/tests/compress_test.py
new file mode 100644
index 0000000..62a07a1
--- /dev/null
+++ b/python/tests/compress_test.py
@@ -0,0 +1,114 @@
+# Copyright 2016 The Brotli Authors. All rights reserved.
+#
+# Distributed under MIT license.
+# See file LICENSE for detail or copy at https://opensource.org/licenses/MIT
+
+import unittest
+
+import _test_utils
+import brotli
+
+
+class TestCompress(_test_utils.TestCase):
+
+    def _check_decompression(self, test_data, **kwargs):
+        # Write decompression to temp file and verify it matches the original.
+        temp_uncompressed = _test_utils.get_temp_uncompressed_name(test_data)
+        temp_compressed = _test_utils.get_temp_compressed_name(test_data)
+        original = test_data
+        with open(temp_uncompressed, 'wb') as out_file:
+            with open(temp_compressed, 'rb') as in_file:
+                out_file.write(brotli.decompress(in_file.read(), **kwargs))
+        self.assertFilesMatch(temp_uncompressed, original)
+
+    def _compress(self, test_data, **kwargs):
+        temp_compressed = _test_utils.get_temp_compressed_name(test_data)
+        with open(temp_compressed, 'wb') as out_file:
+            with open(test_data, 'rb') as in_file:
+                out_file.write(brotli.compress(in_file.read(), **kwargs))
+
+    def _test_compress_quality_1(self, test_data):
+        self._compress(test_data, quality=1)
+        self._check_decompression(test_data)
+
+    def _test_compress_quality_6(self, test_data):
+        self._compress(test_data, quality=6)
+        self._check_decompression(test_data)
+
+    def _test_compress_quality_9(self, test_data):
+        self._compress(test_data, quality=9)
+        self._check_decompression(test_data)
+
+    def _test_compress_quality_11(self, test_data):
+        self._compress(test_data, quality=11)
+        self._check_decompression(test_data)
+
+    def _test_compress_quality_1_lgwin_10(self, test_data):
+        self._compress(test_data, quality=1, lgwin=10)
+        self._check_decompression(test_data)
+
+    def _test_compress_quality_6_lgwin_15(self, test_data):
+        self._compress(test_data, quality=6, lgwin=15)
+        self._check_decompression(test_data)
+
+    def _test_compress_quality_9_lgwin_20(self, test_data):
+        self._compress(test_data, quality=9, lgwin=20)
+        self._check_decompression(test_data)
+
+    def _test_compress_quality_11_lgwin_24(self, test_data):
+        self._compress(test_data, quality=11, lgwin=24)
+        self._check_decompression(test_data)
+
+    def _test_compress_quality_1_custom_dictionary(self, test_data):
+        with open(test_data, 'rb') as in_file:
+            dictionary = in_file.read()
+        self._compress(test_data, quality=1, dictionary=dictionary)
+        self._check_decompression(test_data, dictionary=dictionary)
+
+    def _test_compress_quality_6_custom_dictionary(self, test_data):
+        with open(test_data, 'rb') as in_file:
+            dictionary = in_file.read()
+        self._compress(test_data, quality=6, dictionary=dictionary)
+        self._check_decompression(test_data, dictionary=dictionary)
+
+    def _test_compress_quality_9_custom_dictionary(self, test_data):
+        with open(test_data, 'rb') as in_file:
+            dictionary = in_file.read()
+        self._compress(test_data, quality=9, dictionary=dictionary)
+        self._check_decompression(test_data, dictionary=dictionary)
+
+    def _test_compress_quality_11_custom_dictionary(self, test_data):
+        with open(test_data, 'rb') as in_file:
+            dictionary = in_file.read()
+        self._compress(test_data, quality=11, dictionary=dictionary)
+        self._check_decompression(test_data, dictionary=dictionary)
+
+    def _test_compress_quality_1_lgwin_10_custom_dictionary(self, test_data):
+        with open(test_data, 'rb') as in_file:
+            dictionary = in_file.read()
+        self._compress(test_data, quality=1, lgwin=10, dictionary=dictionary)
+        self._check_decompression(test_data, dictionary=dictionary)
+
+    def _test_compress_quality_6_lgwin_15_custom_dictionary(self, test_data):
+        with open(test_data, 'rb') as in_file:
+            dictionary = in_file.read()
+        self._compress(test_data, quality=6, lgwin=15, dictionary=dictionary)
+        self._check_decompression(test_data, dictionary=dictionary)
+
+    def _test_compress_quality_9_lgwin_20_custom_dictionary(self, test_data):
+        with open(test_data, 'rb') as in_file:
+            dictionary = in_file.read()
+        self._compress(test_data, quality=9, lgwin=20, dictionary=dictionary)
+        self._check_decompression(test_data, dictionary=dictionary)
+
+    def _test_compress_quality_11_lgwin_24_custom_dictionary(self, test_data):
+        with open(test_data, 'rb') as in_file:
+            dictionary = in_file.read()
+        self._compress(test_data, quality=11, lgwin=24, dictionary=dictionary)
+        self._check_decompression(test_data, dictionary=dictionary)
+
+
+_test_utils.generate_test_methods(TestCompress)
+
+if __name__ == '__main__':
+    unittest.main()
diff --git a/python/tests/compressor_test.py b/python/tests/compressor_test.py
index 6983c31..5924e4c 100644
--- a/python/tests/compressor_test.py
+++ b/python/tests/compressor_test.py
@@ -3,135 +3,85 @@
 # Distributed under MIT license.
 # See file LICENSE for detail or copy at https://opensource.org/licenses/MIT
 
-import filecmp
 import functools
-import os
-import sys
-import types
 import unittest
 
-import test_utils
-
+import _test_utils
 import brotli
 
 
-TEST_DATA_FILES = [
-    'empty',  # Empty file
-    '10x10y',  # Small text
-    'alice29.txt',  # Large text
-    'random_org_10k.bin',  # Small data
-    'mapsdatazrh',  # Large data
-]
-TEST_DATA_PATHS = [os.path.join(test_utils.TESTDATA_DIR, f)
-                   for f in TEST_DATA_FILES]
-
-
-def get_compressed_name(filename):
-    return filename + '.compressed'
-
-
-def get_temp_compressed_name(filename):
-    return filename + '.bro'
-
-
-def get_temp_uncompressed_name(filename):
-    return filename + '.unbro'
-
-
-def bind_method_args(method, *args):
-    return lambda self: method(self, *args)
-
-
-# Do not inherit from unittest.TestCase here to ensure that test methods
+# Do not inherit from TestCase here to ensure that test methods
 # are not run automatically and instead are run as part of a specific
 # configuration below.
 class _TestCompressor(object):
 
-    def _check_decompression_matches(self, test_data):
+    CHUNK_SIZE = 2048
+
+    def _check_decompression(self, test_data):
         # Write decompression to temp file and verify it matches the original.
-        with open(get_temp_uncompressed_name(test_data), 'wb') as out_file:
-            with open(get_temp_compressed_name(test_data), 'rb') as in_file:
+        temp_uncompressed = _test_utils.get_temp_uncompressed_name(test_data)
+        temp_compressed = _test_utils.get_temp_compressed_name(test_data)
+        original = test_data
+        with open(temp_uncompressed, 'wb') as out_file:
+            with open(temp_compressed, 'rb') as in_file:
                 out_file.write(brotli.decompress(in_file.read()))
-        self.assertTrue(
-            filecmp.cmp(get_temp_uncompressed_name(test_data),
-                        test_data,
-                        shallow=False))
+        self.assertFilesMatch(temp_uncompressed, original)
 
     def _test_single_process(self, test_data):
         # Write single-shot compression to temp file.
-        with open(get_temp_compressed_name(test_data), 'wb') as out_file:
+        temp_compressed = _test_utils.get_temp_compressed_name(test_data)
+        with open(temp_compressed, 'wb') as out_file:
             with open(test_data, 'rb') as in_file:
                 out_file.write(self.compressor.process(in_file.read()))
             out_file.write(self.compressor.finish())
-        self._check_decompression_matches(test_data)
+        self._check_decompression(test_data)
 
     def _test_multiple_process(self, test_data):
         # Write chunked compression to temp file.
-        chunk_size = 2048
-        with open(get_temp_compressed_name(test_data), 'wb') as out_file:
+        temp_compressed = _test_utils.get_temp_compressed_name(test_data)
+        with open(temp_compressed, 'wb') as out_file:
             with open(test_data, 'rb') as in_file:
-                read_chunk = functools.partial(in_file.read, chunk_size)
+                read_chunk = functools.partial(in_file.read, self.CHUNK_SIZE)
                 for data in iter(read_chunk, b''):
                     out_file.write(self.compressor.process(data))
             out_file.write(self.compressor.finish())
-        self._check_decompression_matches(test_data)
+        self._check_decompression(test_data)
 
     def _test_multiple_process_and_flush(self, test_data):
         # Write chunked and flushed compression to temp file.
-        chunk_size = 2048
-        with open(get_temp_compressed_name(test_data), 'wb') as out_file:
+        temp_compressed = _test_utils.get_temp_compressed_name(test_data)
+        with open(temp_compressed, 'wb') as out_file:
             with open(test_data, 'rb') as in_file:
-                read_chunk = functools.partial(in_file.read, chunk_size)
+                read_chunk = functools.partial(in_file.read, self.CHUNK_SIZE)
                 for data in iter(read_chunk, b''):
                     out_file.write(self.compressor.process(data))
                     out_file.write(self.compressor.flush())
             out_file.write(self.compressor.finish())
-        self._check_decompression_matches(test_data)
-
-
-# Add test methods for each test data file.  This makes identifying problems
-# with specific compression scenarios easier.
-for methodname in [m for m in dir(_TestCompressor) if m.startswith('_test')]:
-    for test_data in TEST_DATA_PATHS:
-        filename = os.path.splitext(os.path.basename(test_data))[0]
-        name = 'test_{method}_{file}'.format(method=methodname, file=filename)
-        func = bind_method_args(getattr(_TestCompressor, methodname), test_data)
-        setattr(_TestCompressor, name, func)
-
+        self._check_decompression(test_data)
 
-class _CompressionTestCase(unittest.TestCase):
 
-    def tearDown(self):
-        for f in TEST_DATA_PATHS:
-            try:
-                os.unlink(get_temp_compressed_name(f))
-            except OSError:
-                pass
-            try:
-                os.unlink(get_temp_uncompressed_name(f))
-            except OSError:
-                pass
+_test_utils.generate_test_methods(_TestCompressor)
 
 
-class TestCompressorQuality1(_TestCompressor, _CompressionTestCase):
+class TestCompressorQuality1(_TestCompressor, _test_utils.TestCase):
 
     def setUp(self):
         self.compressor = brotli.Compressor(quality=1)
 
 
-class TestCompressorQuality6(_TestCompressor, _CompressionTestCase):
+class TestCompressorQuality6(_TestCompressor, _test_utils.TestCase):
 
     def setUp(self):
         self.compressor = brotli.Compressor(quality=6)
 
 
-class TestCompressorQuality9(_TestCompressor, _CompressionTestCase):
+class TestCompressorQuality9(_TestCompressor, _test_utils.TestCase):
 
     def setUp(self):
         self.compressor = brotli.Compressor(quality=9)
 
 
-class TestCompressorQuality11(_TestCompressor, _CompressionTestCase):
+class TestCompressorQuality11(_TestCompressor, _test_utils.TestCase):
 
     def setUp(self):
         self.compressor = brotli.Compressor(quality=11)
diff --git a/python/tests/custom_dictionary_test.py b/python/tests/custom_dictionary_test.py
index a64ee9d..07aa3c1 100644
--- a/python/tests/custom_dictionary_test.py
+++ b/python/tests/custom_dictionary_test.py
@@ -4,7 +4,7 @@ import sys
 import os
 from subprocess import check_call, Popen, PIPE
 
-from test_utils import PYTHON, BRO, TEST_ENV, diff_q
+from _test_utils import PYTHON, BRO, TEST_ENV, diff_q
 
 
 INPUTS = """\
diff --git a/python/tests/decompress_test.py b/python/tests/decompress_test.py
new file mode 100644
index 0000000..536f19a
--- /dev/null
+++ b/python/tests/decompress_test.py
@@ -0,0 +1,38 @@
+# Copyright 2016 The Brotli Authors. All rights reserved.
+#
+# Distributed under MIT license.
+# See file LICENSE for detail or copy at https://opensource.org/licenses/MIT
+
+import unittest
+
+import _test_utils
+import brotli
+
+
+def _get_original_name(test_data):
+    return test_data.split('.compressed')[0]
+
+
+class TestDecompress(_test_utils.TestCase):
+
+    def _check_decompression(self, test_data):
+        # Verify decompression matches the original.
+        temp_uncompressed = _test_utils.get_temp_uncompressed_name(test_data)
+        original = _get_original_name(test_data)
+        self.assertFilesMatch(temp_uncompressed, original)
+
+    def _decompress(self, test_data):
+        temp_uncompressed = _test_utils.get_temp_uncompressed_name(test_data)
+        with open(temp_uncompressed, 'wb') as out_file:
+            with open(test_data, 'rb') as in_file:
+                out_file.write(brotli.decompress(in_file.read()))
+
+    def _test_decompress(self, test_data):
+        self._decompress(test_data)
+        self._check_decompression(test_data)
+
+
+_test_utils.generate_test_methods(TestDecompress, for_decompression=True)
+
+if __name__ == '__main__':
+    unittest.main()
diff --git a/python/tests/roundtrip_test.py b/python/tests/roundtrip_test.py
index 4cb7462..610c4f3 100755..100644
--- a/python/tests/roundtrip_test.py
+++ b/python/tests/roundtrip_test.py
@@ -4,7 +4,7 @@ import sys
 import os
 from subprocess import check_call, Popen, PIPE
 
-from test_utils import PYTHON, BRO, TEST_ENV, diff_q
+from _test_utils import PYTHON, BRO, TEST_ENV, diff_q
 
 
 INPUTS = """\
diff --git a/python/tests/test_utils.py b/python/tests/test_utils.py
deleted file mode 100644
index 2a62a2f..0000000
--- a/python/tests/test_utils.py
+++ /dev/null
@@ -1,39 +0,0 @@
-from __future__ import print_function
-import sys
-import os
-import sysconfig
-import filecmp
-
-
-def diff_q(first_file, second_file):
-    """Simulate call to POSIX diff with -q argument"""
-    if not filecmp.cmp(first_file, second_file, shallow=False):
-        print(
-            'Files %s and %s differ' % (first_file, second_file),
-            file=sys.stderr)
-        return 1
-    return 0
-
-
-project_dir = os.path.abspath(os.path.join(__file__, '..', '..', '..'))
-
-PYTHON = sys.executable or 'python'
-
-BRO = os.path.join(project_dir, 'python', 'bro.py')
-
-TESTDATA_DIR = os.path.join(project_dir, 'tests', 'testdata')
-
-# Get the platform/version-specific build folder.
-# By default, the distutils build base is in the same location as setup.py.
-platform_lib_name = 'lib.{platform}-{version[0]}.{version[1]}'.format(
-    platform=sysconfig.get_platform(), version=sys.version_info)
-build_dir = os.path.join(project_dir, 'bin', platform_lib_name)
-
-# Prepend the build folder to sys.path and the PYTHONPATH environment variable.
-if build_dir not in sys.path:
-    sys.path.insert(0, build_dir)
-TEST_ENV = os.environ.copy()
-if 'PYTHONPATH' not in TEST_ENV:
-    TEST_ENV['PYTHONPATH'] = build_dir
-else:
-    TEST_ENV['PYTHONPATH'] = build_dir + os.pathsep + TEST_ENV['PYTHONPATH']