LibAudio: Test reading and writing of wav files

Includes a set of wav files of different frequencies, these are
each loaded and then written to a temporary file, checking that
the meta-data is correctly read and that the output matches the input.

Tests/LibAudio/CMakeLists.txt

@@ -1,10 +1,13 @@
 set(TEST_SOURCES
+    TestWav.cpp
     TestFLACSpec.cpp
     TestPlaybackStream.cpp
 )
 
 foreach(source IN LISTS TEST_SOURCES)
-    serenity_test("${source}" LibAudio LIBS LibAudio)
+    serenity_test("${source}" LibAudio LIBS LibAudio LibFileSystem)
 endforeach()
 
 install(DIRECTORY ${FLAC_SPEC_TEST_PATH} DESTINATION usr/Tests/LibAudio/FLAC)
+
+install(DIRECTORY WAV DESTINATION usr/Tests/LibAudio)

Tests/LibAudio/TestWav.cpp

@@ -0,0 +1,128 @@
+/*
+ * Copyright (c) 2024, Lee Hanken <github-12-2017-ds8@leehanken.uk>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <AK/ByteString.h>
+#include <AK/LexicalPath.h>
+#include <LibAudio/WavLoader.h>
+#include <LibAudio/WavWriter.h>
+#include <LibCore/Directory.h>
+#include <LibCore/File.h>
+#include <LibFileSystem/FileSystem.h>
+#include <LibFileSystem/TempFile.h>
+#include <LibTest/TestCase.h>
+
+static void compare_files(StringView const& in_path, StringView const& out_path)
+{
+    Array<u8, 4096> buffer1;
+    Array<u8, 4096> buffer2;
+
+    auto original_file = MUST(Core::File::open(in_path, Core::File::OpenMode::Read));
+    auto copied_file = MUST(Core::File::open(out_path, Core::File::OpenMode::Read));
+
+    while (!original_file->is_eof() && !copied_file->is_eof()) {
+        auto original_bytes = TRY_OR_FAIL(original_file->read_some(buffer1));
+        auto copied_bytes = TRY_OR_FAIL(copied_file->read_some(buffer2));
+
+        EXPECT_EQ(original_bytes, copied_bytes);
+    }
+}
+
+static void run_test(StringView file_name, int const num_samples, int const channels, u32 const rate)
+{
+
+    constexpr auto format = "RIFF WAVE (.wav)";
+    constexpr int bits = 16;
+
+    auto out_file = TRY_OR_FAIL(FileSystem::TempFile::create_temp_file());
+    auto out_path = out_file->path();
+
+// This makes sure that the tests will run both on target and in Lagom.
+#ifdef AK_OS_SERENITY
+    ByteString in_path = ByteString::formatted("/usr/Tests/LibAudio/WAV/{}", file_name);
+#else
+    ByteString in_path = ByteString::formatted("WAV/{}", file_name);
+#endif
+
+    auto loader = TRY_OR_FAIL(Audio::Loader::create(in_path));
+
+    EXPECT_EQ(loader->format_name(), format);
+    EXPECT_EQ(loader->sample_rate(), rate);
+    EXPECT_EQ(loader->num_channels(), channels);
+    EXPECT_EQ(loader->bits_per_sample(), bits);
+    EXPECT_EQ(loader->total_samples(), num_samples);
+
+    auto writer = TRY_OR_FAIL(Audio::WavWriter::create_from_file(out_path, rate, channels));
+
+    int samples_read = 0;
+    int size = 0;
+
+    do {
+        auto samples = TRY_OR_FAIL(loader->get_more_samples());
+        TRY_OR_FAIL(writer->write_samples(samples.span()));
+
+        size = samples.size();
+        samples_read += size;
+
+    } while (size);
+
+    TRY_OR_FAIL(writer->finalize());
+
+    EXPECT_EQ(samples_read, num_samples);
+
+    compare_files(in_path, out_path);
+}
+
+// 5 seconds, 16-bit audio samples
+
+TEST_CASE(mono_8khz)
+{
+    run_test("tone_8000_mono.wav"sv, 40000, 1, 8000);
+}
+
+TEST_CASE(stereo_8khz)
+{
+    run_test("tone_8000_stereo.wav"sv, 40000, 2, 8000);
+}
+
+TEST_CASE(mono_11khz)
+{
+    run_test("tone_11025_mono.wav"sv, 55125, 1, 11025);
+}
+
+TEST_CASE(stereo_11khz)
+{
+    run_test("tone_11025_stereo.wav"sv, 55125, 2, 11025);
+}
+
+TEST_CASE(mono_16khz)
+{
+    run_test("tone_16000_mono.wav"sv, 80000, 1, 16000);
+}
+
+TEST_CASE(stereo_16khz)
+{
+    run_test("tone_16000_stereo.wav"sv, 80000, 2, 16000);
+}
+
+TEST_CASE(mono_22khz)
+{
+    run_test("tone_22050_mono.wav"sv, 110250, 1, 22050);
+}
+
+TEST_CASE(stereo_22khz)
+{
+    run_test("tone_22050_stereo.wav"sv, 110250, 2, 22050);
+}
+
+TEST_CASE(mono_44khz)
+{
+    run_test("tone_44100_mono.wav"sv, 220500, 1, 44100);
+}
+
+TEST_CASE(stereo_44khz)
+{
+    run_test("tone_44100_stereo.wav"sv, 220500, 2, 44100);
+}