Tests: Reorganize LibCompress unit tests

Move LibCompress unit tests to LibCompress/Tests directory and register
them with CMake's add_test. This allows us to run these tests with
ninja test instead of running a separate executable.

Also split the existing tests in 3 test files that better follow the
source code structure (inspired by AK tests).

5 files changed, 355 insertions, 0 deletions

diff --git a/Userland/Libraries/LibCompress/CMakeLists.txt b/Userland/Libraries/LibCompress/CMakeLists.txt
index 6fbb50fb8f..90242cf195 100644
--- a/Userland/Libraries/LibCompress/CMakeLists.txt
+++ b/Userland/Libraries/LibCompress/CMakeLists.txt
@@ -6,3 +6,5 @@ set(SOURCES
 
 serenity_lib(LibCompress compress)
 target_link_libraries(LibCompress LibC LibCrypto)
+
+add_subdirectory(Tests)
diff --git a/Userland/Libraries/LibCompress/Tests/CMakeLists.txt b/Userland/Libraries/LibCompress/Tests/CMakeLists.txt
new file mode 100644
index 0000000000..8b15789971
--- /dev/null
+++ b/Userland/Libraries/LibCompress/Tests/CMakeLists.txt
@@ -0,0 +1,8 @@
+file(GLOB TEST_SOURCES CONFIGURE_DEPENDS "*.cpp")
+
+foreach(source ${TEST_SOURCES})
+    get_filename_component(name ${source} NAME_WE)
+    add_executable(${name} ${source})
+    target_link_libraries(${name} LibCore LibCompress)
+    install(TARGETS ${name} RUNTIME DESTINATION usr/Tests/LibCompress)
+endforeach()
diff --git a/Userland/Libraries/LibCompress/Tests/TestDeflate.cpp b/Userland/Libraries/LibCompress/Tests/TestDeflate.cpp
new file mode 100644
index 0000000000..91f2b39cb1
--- /dev/null
+++ b/Userland/Libraries/LibCompress/Tests/TestDeflate.cpp
@@ -0,0 +1,179 @@
+/*
+ * Copyright (c) 2020-2021, the SerenityOS developers.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ *    list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <AK/TestSuite.h>
+
+#include <AK/Array.h>
+#include <AK/MemoryStream.h>
+#include <AK/Random.h>
+#include <LibCompress/Deflate.h>
+#include <cstring>
+
+TEST_CASE(canonical_code_simple)
+{
+    const Array<u8, 32> code {
+        0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05,
+        0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05,
+        0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05
+    };
+    const Array<u8, 6> input {
+        0x00, 0x42, 0x84, 0xa9, 0xb0, 0x15
+    };
+    const Array<u32, 9> output {
+        0x00, 0x01, 0x01, 0x02, 0x03, 0x05, 0x08, 0x0d, 0x15
+    };
+
+    const auto huffman = Compress::CanonicalCode::from_bytes(code).value();
+    auto memory_stream = InputMemoryStream { input };
+    auto bit_stream = InputBitStream { memory_stream };
+
+    for (size_t idx = 0; idx < 9; ++idx)
+        EXPECT_EQ(huffman.read_symbol(bit_stream), output[idx]);
+}
+
+TEST_CASE(canonical_code_complex)
+{
+    const Array<u8, 6> code {
+        0x03, 0x02, 0x03, 0x03, 0x02, 0x03
+    };
+    const Array<u8, 4> input {
+        0xa1, 0xf3, 0xa1, 0xf3
+    };
+    const Array<u32, 12> output {
+        0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x00, 0x01, 0x02, 0x03, 0x04, 0x05
+    };
+
+    const auto huffman = Compress::CanonicalCode::from_bytes(code).value();
+    auto memory_stream = InputMemoryStream { input };
+    auto bit_stream = InputBitStream { memory_stream };
+
+    for (size_t idx = 0; idx < 12; ++idx)
+        EXPECT_EQ(huffman.read_symbol(bit_stream), output[idx]);
+}
+
+TEST_CASE(deflate_decompress_compressed_block)
+{
+    const Array<u8, 28> compressed {
+        0x0B, 0xC9, 0xC8, 0x2C, 0x56, 0x00, 0xA2, 0x44, 0x85, 0xE2, 0xCC, 0xDC,
+        0x82, 0x9C, 0x54, 0x85, 0x92, 0xD4, 0x8A, 0x12, 0x85, 0xB4, 0x4C, 0x20,
+        0xCB, 0x4A, 0x13, 0x00
+    };
+
+    const u8 uncompressed[] = "This is a simple text file :)";
+
+    const auto decompressed = Compress::DeflateDecompressor::decompress_all(compressed);
+    EXPECT(decompressed.value().bytes() == ReadonlyBytes({ uncompressed, sizeof(uncompressed) - 1 }));
+}
+
+TEST_CASE(deflate_decompress_uncompressed_block)
+{
+    const Array<u8, 18> compressed {
+        0x01, 0x0d, 0x00, 0xf2, 0xff, 0x48, 0x65, 0x6c, 0x6c, 0x6f, 0x2c, 0x20,
+        0x57, 0x6f, 0x72, 0x6c, 0x64, 0x21
+    };
+
+    const u8 uncompressed[] = "Hello, World!";
+
+    const auto decompressed = Compress::DeflateDecompressor::decompress_all(compressed);
+    EXPECT(decompressed.value().bytes() == (ReadonlyBytes { uncompressed, sizeof(uncompressed) - 1 }));
+}
+
+TEST_CASE(deflate_decompress_multiple_blocks)
+{
+    const Array<u8, 84> compressed {
+        0x00, 0x1f, 0x00, 0xe0, 0xff, 0x54, 0x68, 0x65, 0x20, 0x66, 0x69, 0x72,
+        0x73, 0x74, 0x20, 0x62, 0x6c, 0x6f, 0x63, 0x6b, 0x20, 0x69, 0x73, 0x20,
+        0x75, 0x6e, 0x63, 0x6f, 0x6d, 0x70, 0x72, 0x65, 0x73, 0x73, 0x65, 0x64,
+        0x53, 0x48, 0xcc, 0x4b, 0x51, 0x28, 0xc9, 0x48, 0x55, 0x28, 0x4e, 0x4d,
+        0xce, 0x07, 0x32, 0x93, 0x72, 0xf2, 0x93, 0xb3, 0x15, 0x32, 0x8b, 0x15,
+        0x92, 0xf3, 0x73, 0x0b, 0x8a, 0x52, 0x8b, 0x8b, 0x53, 0x53, 0xf4, 0x00
+    };
+
+    const u8 uncompressed[] = "The first block is uncompressed and the second block is compressed.";
+
+    const auto decompressed = Compress::DeflateDecompressor::decompress_all(compressed);
+    EXPECT(decompressed.value().bytes() == (ReadonlyBytes { uncompressed, sizeof(uncompressed) - 1 }));
+}
+
+TEST_CASE(deflate_decompress_zeroes)
+{
+    const Array<u8, 20> compressed {
+        0xed, 0xc1, 0x01, 0x0d, 0x00, 0x00, 0x00, 0xc2, 0xa0, 0xf7, 0x4f, 0x6d,
+        0x0f, 0x07, 0x14, 0x00, 0x00, 0x00, 0xf0, 0x6e
+    };
+
+    const Array<u8, 4096> uncompressed { 0 };
+
+    const auto decompressed = Compress::DeflateDecompressor::decompress_all(compressed);
+    EXPECT(uncompressed == decompressed.value().bytes());
+}
+
+TEST_CASE(deflate_round_trip_store)
+{
+    auto original = ByteBuffer::create_uninitialized(1024);
+    fill_with_random(original.data(), 1024);
+    auto compressed = Compress::DeflateCompressor::compress_all(original, Compress::DeflateCompressor::CompressionLevel::STORE);
+    EXPECT(compressed.has_value());
+    auto uncompressed = Compress::DeflateDecompressor::decompress_all(compressed.value());
+    EXPECT(uncompressed.has_value());
+    EXPECT(uncompressed.value() == original);
+}
+
+TEST_CASE(deflate_round_trip_compress)
+{
+    auto original = ByteBuffer::create_uninitialized(2048);
+    fill_with_random(original.data(), 1024);
+    memset(original.offset_pointer(1024), 0, 1024); // we fill the second half with 0s to make sure we test back references as well
+    // Since the different levels just change how much time is spent looking for better matches, just use fast here to reduce test time
+    auto compressed = Compress::DeflateCompressor::compress_all(original, Compress::DeflateCompressor::CompressionLevel::FAST);
+    EXPECT(compressed.has_value());
+    auto uncompressed = Compress::DeflateDecompressor::decompress_all(compressed.value());
+    EXPECT(uncompressed.has_value());
+    EXPECT(uncompressed.value() == original);
+}
+
+TEST_CASE(deflate_round_trip_compress_large)
+{
+    auto size = Compress::DeflateCompressor::block_size * 2;
+    auto original = ByteBuffer::create_uninitialized(size); // Compress a buffer larger than the maximum block size to test the sliding window mechanism
+    fill_with_random(original.data(), size);
+    // Since the different levels just change how much time is spent looking for better matches, just use fast here to reduce test time
+    auto compressed = Compress::DeflateCompressor::compress_all(original, Compress::DeflateCompressor::CompressionLevel::FAST);
+    EXPECT(compressed.has_value());
+    auto uncompressed = Compress::DeflateDecompressor::decompress_all(compressed.value());
+    EXPECT(uncompressed.has_value());
+    EXPECT(uncompressed.value() == original);
+}
+
+TEST_CASE(deflate_compress_literals)
+{
+    // This byte array is known to not produce any back references with our lz77 implementation even at the highest compression settings
+    Array<u8, 0x13> test { 0, 0, 0, 0, 0x72, 0, 0, 0xee, 0, 0, 0, 0x26, 0, 0, 0, 0x28, 0, 0, 0x72 };
+    auto compressed = Compress::DeflateCompressor::compress_all(test, Compress::DeflateCompressor::CompressionLevel::GOOD);
+    EXPECT(compressed.has_value());
+}
+
+TEST_MAIN(Deflate)
diff --git a/Userland/Libraries/LibCompress/Tests/TestGzip.cpp b/Userland/Libraries/LibCompress/Tests/TestGzip.cpp
new file mode 100644
index 0000000000..f816ee3902
--- /dev/null
+++ b/Userland/Libraries/LibCompress/Tests/TestGzip.cpp
@@ -0,0 +1,119 @@
+/*
+ * Copyright (c) 2020-2021, the SerenityOS developers.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ *    list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <AK/TestSuite.h>
+
+#include <AK/Array.h>
+#include <AK/Random.h>
+#include <LibCompress/Gzip.h>
+
+TEST_CASE(gzip_decompress_simple)
+{
+    const Array<u8, 33> compressed {
+        0x1f, 0x8b, 0x08, 0x00, 0x77, 0xff, 0x47, 0x5f, 0x02, 0xff, 0x2b, 0xcf,
+        0x2f, 0x4a, 0x31, 0x54, 0x48, 0x4c, 0x4a, 0x56, 0x28, 0x07, 0xb2, 0x8c,
+        0x00, 0xc2, 0x1d, 0x22, 0x15, 0x0f, 0x00, 0x00, 0x00
+    };
+
+    const u8 uncompressed[] = "word1 abc word2";
+
+    const auto decompressed = Compress::GzipDecompressor::decompress_all(compressed);
+    EXPECT(decompressed.value().bytes() == (ReadonlyBytes { uncompressed, sizeof(uncompressed) - 1 }));
+}
+
+TEST_CASE(gzip_decompress_multiple_members)
+{
+    const Array<u8, 52> compressed {
+        0x1f, 0x8b, 0x08, 0x00, 0xe0, 0x03, 0x48, 0x5f, 0x02, 0xff, 0x4b, 0x4c,
+        0x4a, 0x4e, 0x4c, 0x4a, 0x06, 0x00, 0x4c, 0x99, 0x6e, 0x72, 0x06, 0x00,
+        0x00, 0x00, 0x1f, 0x8b, 0x08, 0x00, 0xe0, 0x03, 0x48, 0x5f, 0x02, 0xff,
+        0x4b, 0x4c, 0x4a, 0x4e, 0x4c, 0x4a, 0x06, 0x00, 0x4c, 0x99, 0x6e, 0x72,
+        0x06, 0x00, 0x00, 0x00
+    };
+
+    const u8 uncompressed[] = "abcabcabcabc";
+
+    const auto decompressed = Compress::GzipDecompressor::decompress_all(compressed);
+    EXPECT(decompressed.value().bytes() == (ReadonlyBytes { uncompressed, sizeof(uncompressed) - 1 }));
+}
+
+TEST_CASE(gzip_decompress_zeroes)
+{
+    const Array<u8, 161> compressed {
+        0x1f, 0x8b, 0x08, 0x00, 0x6e, 0x7a, 0x4b, 0x5f, 0x02, 0xff, 0xed, 0xc1,
+        0x31, 0x01, 0x00, 0x00, 0x00, 0xc2, 0xa0, 0xf5, 0x4f, 0xed, 0x61, 0x0d,
+        0xa0, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x6e, 0xcd, 0xcd, 0xe8,
+        0x7e, 0x00, 0x00, 0x02, 0x00
+    };
+
+    const Array<u8, 128 * 1024> uncompressed = { 0 };
+
+    const auto decompressed = Compress::GzipDecompressor::decompress_all(compressed);
+    EXPECT(uncompressed == decompressed.value().bytes());
+}
+
+TEST_CASE(gzip_decompress_repeat_around_buffer)
+{
+    const Array<u8, 70> compressed {
+        0x1f, 0x8b, 0x08, 0x00, 0xc6, 0x74, 0x53, 0x5f, 0x02, 0xff, 0xed, 0xc1,
+        0x01, 0x0d, 0x00, 0x00, 0x0c, 0x02, 0xa0, 0xdb, 0xbf, 0xf4, 0x37, 0x6b,
+        0x08, 0x24, 0xdb, 0x0e, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x80, 0xca,
+        0xb8, 0x07, 0xcd, 0xe5, 0x38, 0xfa, 0x00, 0x80, 0x00, 0x00
+    };
+
+    Array<u8, 0x8000> uncompressed;
+    uncompressed.span().slice(0x0000, 0x0100).fill(1);
+    uncompressed.span().slice(0x0100, 0x7e00).fill(0);
+    uncompressed.span().slice(0x7f00, 0x0100).fill(1);
+
+    const auto decompressed = Compress::GzipDecompressor::decompress_all(compressed);
+    EXPECT(uncompressed == decompressed.value().bytes());
+}
+
+TEST_CASE(gzip_round_trip)
+{
+    auto original = ByteBuffer::create_uninitialized(1024);
+    fill_with_random(original.data(), 1024);
+    auto compressed = Compress::GzipCompressor::compress_all(original);
+    EXPECT(compressed.has_value());
+    auto uncompressed = Compress::GzipDecompressor::decompress_all(compressed.value());
+    EXPECT(uncompressed.has_value());
+    EXPECT(uncompressed.value() == original);
+}
+
+TEST_MAIN(Gzip)
diff --git a/Userland/Libraries/LibCompress/Tests/TestZlib.cpp b/Userland/Libraries/LibCompress/Tests/TestZlib.cpp
new file mode 100644
index 0000000000..3b1cd37f77
--- /dev/null
+++ b/Userland/Libraries/LibCompress/Tests/TestZlib.cpp
@@ -0,0 +1,47 @@
+/*
+ * Copyright (c) 2020-2021, the SerenityOS developers.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ *    list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <AK/TestSuite.h>
+
+#include <AK/Array.h>
+#include <LibCompress/Zlib.h>
+
+TEST_CASE(zlib_decompress_simple)
+{
+    const Array<u8, 40> compressed {
+        0x78, 0x01, 0x01, 0x1D, 0x00, 0xE2, 0xFF, 0x54, 0x68, 0x69, 0x73, 0x20,
+        0x69, 0x73, 0x20, 0x61, 0x20, 0x73, 0x69, 0x6D, 0x70, 0x6C, 0x65, 0x20,
+        0x74, 0x65, 0x78, 0x74, 0x20, 0x66, 0x69, 0x6C, 0x65, 0x20, 0x3A, 0x29,
+        0x99, 0x5E, 0x09, 0xE8
+    };
+
+    const u8 uncompressed[] = "This is a simple text file :)";
+
+    const auto decompressed = Compress::Zlib::decompress_all(compressed);
+    EXPECT(decompressed.value().bytes() == (ReadonlyBytes { uncompressed, sizeof(uncompressed) - 1 }));
+}
+
+TEST_MAIN(Zlib)