feat: add brotli example to test suite (#259)

- include tests/examples/brotli in the members list of mcpp.toml
- enables testing for brotli library integration

Author: yizhinailong

mcpp.toml

@@ -17,6 +17,7 @@ members = [
     "tests/examples/boost-throw-exception",
     "tests/examples/boost-type-traits",
     "tests/examples/boost-uuid",
+    "tests/examples/brotli",
     "tests/examples/build-mcpp",
     "tests/examples/c-ares",
     "tests/examples/catch2",

pkgs/c/compat.brotli.lua

@@ -0,0 +1,56 @@
+-- Form B C-source compat descriptor for Brotli. The three source globs match
+-- upstream v1.2.0's BROTLI_COMMON_SOURCES, BROTLI_DEC_SOURCES, and
+-- BROTLI_ENC_SOURCES CMake sets; the CLI, tests, fuzzers, and the optional C++
+-- lazy static-initialization implementation are outside those sets.
+package = {
+    spec        = "1",
+    namespace   = "compat",
+    name        = "brotli",
+    description = "Brotli compression library",
+    licenses    = {"MIT"},
+    repo        = "https://github.com/google/brotli",
+    type        = "package",
+
+    xpm = {
+        linux = {
+            ["1.2.0"] = {
+                url    = "https://github.com/google/brotli/archive/refs/tags/v1.2.0.tar.gz",
+                sha256 = "816c96e8e8f193b40151dad7e8ff37b1221d019dbcb9c35cd3fadbfe6477dfec",
+            },
+        },
+        macosx = {
+            ["1.2.0"] = {
+                url    = "https://github.com/google/brotli/archive/refs/tags/v1.2.0.tar.gz",
+                sha256 = "816c96e8e8f193b40151dad7e8ff37b1221d019dbcb9c35cd3fadbfe6477dfec",
+            },
+        },
+        windows = {
+            ["1.2.0"] = {
+                url    = "https://github.com/google/brotli/archive/refs/tags/v1.2.0.tar.gz",
+                sha256 = "816c96e8e8f193b40151dad7e8ff37b1221d019dbcb9c35cd3fadbfe6477dfec",
+            },
+        },
+    },
+
+    mcpp = {
+        language     = "c++23",
+        import_std   = false,
+        c_standard   = "c11",
+        include_dirs = { "*/c/include" },
+        sources      = {
+            "*/c/common/*.c",
+            "*/c/dec/*.c",
+            "*/c/enc/*.c",
+        },
+        targets = { ["brotli"] = { kind = "lib" } },
+        deps    = {},
+
+        -- Upstream detects libm and propagates it for static builds.
+        linux   = { ldflags = { "-lm" } },
+        macosx  = { ldflags = { "-lm" } },
+        windows = {
+            -- This is upstream's only MSVC-specific library definition.
+            cflags = { "-D_CRT_SECURE_NO_WARNINGS" },
+        },
+    },
+}

tests/examples/brotli/mcpp.toml

@@ -0,0 +1,8 @@
+# Brotli test project: consumes compat.brotli through the workspace-root
+# `compat` index redirect and exercises encoder, decoder, and common code.
+[package]
+name = "brotli-tests"
+version = "0.1.0"
+
+[dependencies.compat]
+brotli = "1.2.0"

tests/examples/brotli/tests/roundtrip.cpp

@@ -0,0 +1,43 @@
+#include <brotli/decode.h>
+#include <brotli/encode.h>
+
+#include <cstddef>
+#include <cstring>
+#include <vector>
+
+int main() {
+    static constexpr unsigned char original[] =
+        "Brotli round-trip payload. Brotli round-trip payload. "
+        "Brotli round-trip payload. Brotli round-trip payload.";
+    constexpr std::size_t original_size = sizeof(original) - 1;
+
+    const std::size_t encoded_capacity = BrotliEncoderMaxCompressedSize(original_size);
+    if (original_size == 0 || encoded_capacity == 0) return 1;
+
+    std::vector<unsigned char> encoded(encoded_capacity);
+    std::size_t encoded_size = encoded.size();
+    const BROTLI_BOOL encoded_ok = BrotliEncoderCompress(
+        BROTLI_DEFAULT_QUALITY,
+        BROTLI_DEFAULT_WINDOW,
+        BROTLI_MODE_GENERIC,
+        original_size,
+        original,
+        &encoded_size,
+        encoded.data());
+    if (encoded_ok != BROTLI_TRUE || encoded_size == 0) return 2;
+
+    std::vector<unsigned char> decoded(original_size);
+    std::size_t decoded_size = decoded.size();
+    const BrotliDecoderResult decoded_result = BrotliDecoderDecompress(
+        encoded_size,
+        encoded.data(),
+        &decoded_size,
+        decoded.data());
+    if (decoded_result != BROTLI_DECODER_RESULT_SUCCESS) return 3;
+    if (decoded_size != original_size) return 4;
+
+    for (std::size_t i = 0; i < original_size; ++i) {
+        if (decoded[i] != original[i]) return 5;
+    }
+    return std::memcmp(decoded.data(), original, original_size) == 0 ? 0 : 6;
+}