fuzz: utility fuzz test

test/common/common/BUILD

@@ -26,6 +26,13 @@ envoy_cc_fuzz_test(
     deps = ["//source/common/common:base64_lib"],
 )
 
+envoy_cc_fuzz_test(
+    name = "utility_fuzz_test",
+    srcs = ["utility_fuzz_test.cc"],
+    corpus = "utility_corpus",
+    deps = ["//source/common/common:utility_lib"],
+)
+
 envoy_cc_test(
     name = "cleanup_test",
     srcs = ["cleanup_test.cc"],

test/common/common/utility_corpus/test

@@ -0,0 +1 @@
+hello world

test/common/common/utility_fuzz_test.cc

@@ -0,0 +1,63 @@
+#include "common/common/utility.h"
+
+#include "test/fuzz/fuzz_runner.h"
+
+#include "absl/strings/string_view.h"
+
+namespace Envoy {
+namespace Fuzz {
+
+DEFINE_FUZZER(const uint8_t* buf, size_t len) {
+  {
+    uint64_t out;
+    const std::string string_buffer(reinterpret_cast<const char*>(buf), len);
+    StringUtil::atoul(string_buffer.c_str(), out);
+  }
+  {
+    const std::string string_buffer(reinterpret_cast<const char*>(buf), len);
+    StringUtil::escape(string_buffer);
+  }
+  {
+    const std::string string_buffer(reinterpret_cast<const char*>(buf), len);
+    StringUtil::toUpper(string_buffer);
+  }
+  {
+    const std::string string_buffer(reinterpret_cast<const char*>(buf), len);
+    StringUtil::trim(string_buffer);
+  }
+  {
+    const std::string string_buffer(reinterpret_cast<const char*>(buf), len);
+    StringUtil::ltrim(string_buffer);
+  }
+  {
+    const std::string string_buffer(reinterpret_cast<const char*>(buf), len);
+    StringUtil::rtrim(string_buffer);
+  }
+  if (len > 0) {
+    const size_t split_point = *reinterpret_cast<const uint8_t*>(buf) % len;
+    //  (string_buffer.substr(0, split_point), string_buffer.substr(split_point))
+    //  @param1: substring of buffer from beginning to split_point
+    //  @param2: substring of buffer from split_point to end of the string
+    {
+      const std::string string_buffer(reinterpret_cast<const char*>(buf), len);
+      StringUtil::endsWith(string_buffer.substr(0, split_point), string_buffer.substr(split_point));
+    }
+    {
+      const std::string string_buffer(reinterpret_cast<const char*>(buf), len);
+      StringUtil::caseCompare(string_buffer.substr(0, split_point),
+                              string_buffer.substr(split_point));
+    }
+    {
+      const std::string string_buffer(reinterpret_cast<const char*>(buf), len);
+      StringUtil::cropLeft(string_buffer.substr(0, split_point), string_buffer.substr(split_point));
+    }
+    {
+      const std::string string_buffer(reinterpret_cast<const char*>(buf), len);
+      StringUtil::cropRight(string_buffer.substr(0, split_point),
+                            string_buffer.substr(split_point));
+    }
+  }
+}
+
+} // namespace Fuzz
+} // namespace Envoy