Remove fuzztest support from OR-Tools (#4938)

* Remove fuzztest support from OR-Tools

Author: gchatelet

CMakeLists.txt

@@ -202,32 +202,15 @@ if(BUILD_TESTING)
   CMAKE_DEPENDENT_OPTION(BUILD_benchmark "Build benchmark" OFF
     "NOT BUILD_DEPS" ON)
   set(BUILD_protobuf_matchers ON)
-  # Fuzztest do not support MSVC or toolchain
-  if(APPLE OR MSVC OR CMAKE_CROSSCOMPILING)
-    set(USE_fuzztest OFF)
-  else()
-    # since no distro provide a fuzztest package disable support by default.
-    CMAKE_DEPENDENT_OPTION(USE_fuzztest "Enable fuzztest" ${BUILD_DEPS} "BUILD_CXX" OFF)
-  endif()
-  if(NOT USE_fuzztest)
-    set(BUILD_fuzztest OFF)
-  else()
-    CMAKE_DEPENDENT_OPTION(BUILD_fuzztest "Build fuzztest" OFF
-      "NOT BUILD_DEPS" ON)
-  endif()
 else()
   set(OR_TOOLS_BUILD_TESTING OFF)
   set(BUILD_googletest OFF)
   set(BUILD_protobuf_matchers OFF)
   set(BUILD_benchmark OFF)
-  set(USE_fuzztest OFF)
-  set(BUILD_fuzztest OFF)
 endif()
 message(STATUS "Build googletest: ${BUILD_googletest}")
 message(STATUS "Build protobuf_matchers: ${BUILD_protobuf_matchers}")
 message(STATUS "Build benchmark: ${BUILD_benchmark}")
-message(STATUS "Enable fuzztest: ${USE_fuzztest}")
-message(STATUS "Build fuzztest: ${BUILD_fuzztest}")
 
 # Optional third party solvers (enabled by default)
 ## BOP

MODULE.bazel

@@ -41,7 +41,6 @@ bazel_dep(name = "rules_shell", version = "0.6.1")
 bazel_dep(name = "abseil-cpp", version = "20250814.1")
 bazel_dep(name = "bzip2", version = "1.0.8.bcr.2")
 bazel_dep(name = "eigen", version = "3.4.0.bcr.3")
-bazel_dep(name = "fuzztest", version = "20250805.0")
 bazel_dep(name = "glpk", version = "5.0.bcr.4")
 bazel_dep(name = "google_benchmark", version = "1.9.2")
 bazel_dep(name = "googletest", version = "1.17.0")

cmake/check_deps.cmake

@@ -121,9 +121,6 @@ if(BUILD_TESTING)
   if(NOT TARGET benchmark::benchmark)
     message(FATAL_ERROR "Target benchmark::benchmark not available.")
   endif()
-  if(USE_fuzztest AND NOT TARGET fuzztest::fuzztest)
-    message(FATAL_ERROR "Target fuzztest::fuzztest not available.")
-  endif()
 endif()
 
 # Check language Dependencies

cmake/dependencies/CMakeLists.txt

@@ -573,20 +573,3 @@ if(BUILD_benchmark)
   list(POP_BACK CMAKE_MESSAGE_INDENT)
   message(CHECK_PASS "fetched")
 endif()
-
-if(BUILD_fuzztest)
-  message(CHECK_START "Fetching fuzztest")
-  list(APPEND CMAKE_MESSAGE_INDENT "  ")
-  FetchContent_Declare(
-    fuzztest
-    GIT_REPOSITORY https://github.com/google/fuzztest.git
-    GIT_TAG 2025-08-05
-    GIT_SHALLOW TRUE
-    UPDATE_COMMAND git reset --hard
-    PATCH_COMMAND git apply --ignore-whitespace
-    "${CMAKE_CURRENT_LIST_DIR}/../../patches/fuzztest-2025-08-05.patch"
-  )
-  FetchContent_MakeAvailable(fuzztest)
-  list(POP_BACK CMAKE_MESSAGE_INDENT)
-  message(CHECK_PASS "fetched")
-endif()

cmake/system_deps.cmake

@@ -112,12 +112,6 @@ if(BUILD_TESTING)
   if(NOT BUILD_benchmark AND NOT TARGET benchmark::benchmark)
     find_package(benchmark REQUIRED)
   endif()
-
-  if(USE_fuzztest)
-    if(NOT BUILD_fuzztest AND NOT TARGET fuzztest::fuzztest)
-      find_package(fuzztest REQUIRED)
-    endif()
-  endif()
 endif()
 
 # Check language Dependencies

ortools/algorithms/BUILD.bazel

@@ -435,3 +435,20 @@ cc_library(
         "@abseil-cpp//absl/time",
     ],
 )
+
+cc_test(
+    name = "n_choose_k_test",
+    srcs = ["n_choose_k_test.cc"],
+    deps = [
+        ":n_choose_k",
+        "//ortools/base:dump_vars",
+        "//ortools/base:gmock_main",
+        "//ortools/util:flat_matrix",
+        "@abseil-cpp//absl/numeric:int128",
+        "@abseil-cpp//absl/random",
+        "@abseil-cpp//absl/random:distributions",
+        "@abseil-cpp//absl/status",
+        "@abseil-cpp//absl/status:statusor",
+        "@google_benchmark//:benchmark",
+    ],
+)

ortools/algorithms/CMakeLists.txt

@@ -52,20 +52,6 @@ if(BUILD_TESTING)
         GTest::gmock
     )
   endforeach()
-  if(USE_fuzztest)
-    ortools_cxx_test(
-      NAME
-      algorithms_n_choose_k_test
-      SOURCES
-      "./n_choose_k_test.cc"
-      LINK_LIBRARIES
-      benchmark::benchmark
-      fuzztest::fuzztest
-      fuzztest::fuzztest_gtest_main
-      GTest::gmock
-    )
-  endif()
-
   # These tests are too long so we disable them.
   set_tests_properties(
     cxx_algorithms_radix_sort_test

ortools/algorithms/n_choose_k_test.cc

@@ -16,26 +16,19 @@
 #include <cmath>
 #include <cstdint>
 #include <limits>
-#include <random>
-#include <utility>
-#include <vector>
 
 #include "absl/numeric/int128.h"
 #include "absl/random/distributions.h"
 #include "absl/random/random.h"
 #include "absl/status/status.h"
 #include "absl/status/statusor.h"
-#include "benchmark/benchmark.h"
 #include "gtest/gtest.h"
 #include "ortools/base/dump_vars.h"
-//#include "ortools/base/fuzztest.h"
 #include "ortools/base/gmock.h"
-#include "ortools/base/mathutil.h"
 #include "ortools/util/flat_matrix.h"
 
 namespace operations_research {
 namespace {
-//using ::fuzztest::NonNegative;
 using ::testing::HasSubstr;
 using ::testing::status::IsOkAndHolds;
 using ::testing::status::StatusIs;
@@ -248,74 +241,5 @@ TEST(NChooseKTest, ComparisonAgainstPascalTriangleForK5OrAbove) {
   }
 }
 
-void MatchesLogCombinations(int n, int k) {
-  if (n < k) {
-    std::swap(k, n);
-  }
-  const auto exact = NChooseK(n, k);
-  const double log_approx = MathUtil::LogCombinations(n, k);
-  if (exact.ok()) {
-    // We accepted to compute the exact value, make sure that it matches the
-    // approximation.
-    ASSERT_NEAR(log(exact.value()), log_approx, 0.0001);
-  } else {
-    // We declined to compute the exact value, make sure that we had a good
-    // reason to, i.e. that the result did indeed overflow.
-    ASSERT_THAT(exact, StatusIs(absl::StatusCode::kInvalidArgument,
-                                HasSubstr("overflows int64")));
-    const double approx = exp(log_approx);
-    ASSERT_GE(std::nextafter(approx, std::numeric_limits<double>::infinity()),
-              std::numeric_limits<int64_t>::max())
-        << "we declined to compute the exact value of NChooseK(" << n << ", "
-        << k << "), but the log value is " << log_approx
-        << " (value: " << approx << "), which fits in int64_t";
-  }
-}
-/*
-FUZZ_TEST(NChooseKTest, MatchesLogCombinations)
-    // Ideally we'd test with `uint64_t`, but `LogCombinations` only accepts
-    // `int`.
-    .WithDomains(NonNegative<int>(), NonNegative<int>());
-*/
-template <int kMaxN, auto algo>
-void BM_NChooseK(benchmark::State& state) {
-  static constexpr int kNumInputs = 1000;
-  // Use deterministic random numbers to avoid noise.
-  std::mt19937 gen(42);
-  std::uniform_int_distribution<int64_t> random(0, kMaxN);
-  std::vector<std::pair<int64_t, int64_t>> inputs;
-  inputs.reserve(kNumInputs);
-  for (int i = 0; i < kNumInputs; ++i) {
-    int64_t n = random(gen);
-    int64_t k = random(gen);
-    if (n < k) {
-      std::swap(n, k);
-    }
-    inputs.emplace_back(n, k);
-  }
-  // Force the one-time, costly static initializations of NChooseK() to happen
-  // before the benchmark starts.
-  auto result = NChooseK(62, 31);
-  benchmark::DoNotOptimize(result);
-
-  // Start the benchmark.
-  for (auto _ : state) {
-    for (const auto [n, k] : inputs) {
-      auto result = algo(n, k);
-      benchmark::DoNotOptimize(result);
-    }
-  }
-  state.SetItemsProcessed(state.iterations() * kNumInputs);
-}
-// int32_t domain.
-BENCHMARK(BM_NChooseK<30, operations_research::NChooseK>);
-
-// int{32,64} domain.
-BENCHMARK(BM_NChooseK<60, operations_research::NChooseK>);
-
-// int{32,64,128} domain.
-BENCHMARK(BM_NChooseK<100, operations_research::NChooseK>);
-BENCHMARK(BM_NChooseK<100, MathUtil::LogCombinations>);
-
 }  // namespace
 }  // namespace operations_research

ortools/base/fuzztest.h

@@ -50,8 +50,6 @@ if(BUILD_TESTING)
   file(GLOB _TEST_SRCS "*_test.cc")
   list(FILTER _TEST_SRCS
     EXCLUDE REGEX "elemental_export_model_update_test.cc$")
-  list(FILTER _TEST_SRCS
-    EXCLUDE REGEX "elemental_from_proto_fuzz_test.cc$") # need fuzztest
   foreach(_FULL_FILE_NAME IN LISTS _TEST_SRCS)
     get_filename_component(_NAME ${_FULL_FILE_NAME} NAME_WE)
     get_filename_component(_FILE_NAME ${_FULL_FILE_NAME} NAME)