Set up FuzzTest and use Clang.

PiperOrigin-RevId: 698895223

.bazelrc

@@ -1,3 +1,17 @@
 # Use C++ 20.
 build --cxxopt=-std=c++20
 build --host_cxxopt=-std=c++20
+
+# Force the use of Clang for all builds. FuzzTest relies on Clang for sanitizer
+# coverage (https://clang.llvm.org/docs/SanitizerCoverage.html).
+build --action_env=CC=clang
+build --action_env=CXX=clang++
+
+# Show everything when running tests.
+test --test_output=streamed
+
+# To create this file, please run:
+#
+#  bazel run @com_google_fuzztest//bazel:setup_configs > fuzztest.bazelrc
+#
+try-import %workspace%/fuzztest.bazelrc

.github/workflows/build.yml

@@ -25,9 +25,9 @@ jobs:
         uses: actions/cache/restore@v4
         with:
           path: "~/.cache/bazel"
-          key: bazel-${{ hashFiles('MODULE.bazel', 'WORKSPACE.bazel', '.bazelrc') }}-${{ github.ref_name }}
+          key: bazel-${{ hashFiles('*.bazel', '*.bazelrc') }}-${{ github.ref_name }}
           restore-keys: |
-            bazel-${{hashFiles('MODULE.bazel', 'WORKSPACE.bazel', '.bazelrc') }}
+            bazel-${{hashFiles('*.bazel', '*.bazelrc') }}
             bazel-
 
       - name: Save start time
@@ -66,4 +66,4 @@ jobs:
         if: github.ref_name == 'main' || env.duration > 300
         with:
           path: "~/.cache/bazel"
-          key: bazel-${{ hashFiles('MODULE.bazel', 'WORKSPACE.bazel', '.bazelrc') }}-${{ github.ref_name }}-${{ github.run_id }}
+          key: bazel-${{ hashFiles('*.bazel', '*.bazelrc') }}-${{ github.ref_name }}-${{ github.run_id }}

.gitignore

@@ -0,0 +1,5 @@
+# Don't track lock files.
+*.lock
+
+# Don't track Bazel output folders.
+bazel-*

MODULE.bazel

@@ -21,7 +21,10 @@ module(
     compatibility_level = 1,
 )
 
-bazel_dep(name = "rules_license", version = "1.0.0")
 bazel_dep(name = "protobuf", version = "28.2", repo_name = "com_google_protobuf")
 bazel_dep(name = "abseil-cpp", version = "20240116.2", repo_name = "com_google_absl")
-bazel_dep(name = "googletest", version = "1.15.2", repo_name = "com_google_googletest")
+
+# Dev Depdencies.
+bazel_dep(name = "rules_license", version = "1.0.0", dev_dependency = True)
+bazel_dep(name = "googletest", version = "1.15.2", dev_dependency = True, repo_name = "com_google_googletest")
+bazel_dep(name = "fuzztest", version = "20241028.0", dev_dependency = True, repo_name = "com_google_fuzztest")

fuzztest.bazelrc

@@ -0,0 +1,44 @@
+### DO NOT EDIT. Generated file.
+#
+# To regenerate, run the following from your project's workspace:
+#
+#  bazel run @com_google_fuzztest//bazel:setup_configs > fuzztest.bazelrc
+#
+# And don't forget to add the following to your project's .bazelrc:
+#
+#  try-import %workspace%/fuzztest.bazelrc
+### Common options.
+#
+# Do not use directly.
+
+# Standard define for \"ifdef-ing\" any fuzz test specific code.
+build:fuzztest-common --copt=-DFUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
+
+# In fuzz tests, we want to catch assertion violations even in optimized builds.
+build:fuzztest-common --copt=-UNDEBUG
+
+# Enable libc++ assertions.
+# See https://libcxx.llvm.org/UsingLibcxx.html#enabling-the-safe-libc-mode
+build:fuzztest-common --copt=-D_LIBCPP_ENABLE_ASSERTIONS=1
+### ASan (Address Sanitizer) build configuration.
+#
+# Use with: --config=asan
+
+build:asan --linkopt=-fsanitize=address
+build:asan --copt=-fsanitize=address
+### FuzzTest build configuration.
+#
+# Use with: --config=fuzztest
+#
+# Note that this configuration includes the ASan configuration.
+
+build:fuzztest --config=asan
+build:fuzztest --config=fuzztest-common
+
+# Link statically.
+build:fuzztest --dynamic_mode=off
+
+# We rely on the following flag instead of the compiler provided
+# __has_feature(address_sanitizer) to know that we have an ASAN build even in
+# the uninstrumented runtime.
+build:fuzztest --copt=-DADDRESS_SANITIZER

netkat/BUILD.bazel

@@ -22,6 +22,7 @@ cc_test(
     deps = [
         ":netkat_cc_proto",
         "@com_google_absl//absl/log",
+        "@com_google_fuzztest//fuzztest",
         "@com_google_googletest//:gtest_main",
     ],
 )

netkat/netkat_test.cc

@@ -14,12 +14,20 @@
 // -----------------------------------------------------------------------------
 
 #include "absl/log/log.h"
+#include "fuzztest/fuzztest.h"
 #include "gtest/gtest.h"
 #include "netkat/netkat.pb.h"
 
 namespace netkat {
 namespace {
 
+// Sanity fuzz test to show that the FuzzTest library works.
+void DummmyFuzzTest(PredicateProto pred, PolicyProto pol) {
+  LOG_EVERY_N_SEC(INFO, 1) << "pred = " << pred;
+  LOG_EVERY_N_SEC(INFO, 1) << "pol = " << pol;
+}
+FUZZ_TEST(NetkatProtoTest, DummmyFuzzTest);
+
 // Ensures that the protobuf C++ compiler does not add underscores to the
 // generated code for sub messages and oneof fields of `PredicateProto`.
 //