/*

 * A fuzzer focused on the node::LoadEnvironment() function.

 *

 * Code here has been inspired by the cctest test case.

 */

#include <stdlib.h>

#include "node.h"

#include "node_platform.h"

#include "node_internals.h"

#include "env-inl.h"

#include "util-inl.h"

#include "v8.h"

#include "libplatform/libplatform.h"

#include "aliased_buffer.h"

#include "fuzz_helper.h"

#include <fuzzer/FuzzedDataProvider.h>

#include <cstdio>

using node::AliasedBufferBase;

/* General set up */

using ArrayBufferUniquePtr = std::unique_ptr<node::ArrayBufferAllocator,

  decltype(&node::FreeArrayBufferAllocator)>;

using TracingAgentUniquePtr = std::unique_ptr<node::tracing::Agent>;

using NodePlatformUniquePtr = std::unique_ptr<node::NodePlatform>;

static TracingAgentUniquePtr tracing_agent;

static NodePlatformUniquePtr platform;

static uv_loop_t current_loop;

extern "C" int LLVMFuzzerInitialize(int* argc, char*** argv) {

  uv_os_unsetenv("NODE_OPTIONS");

  std::vector<std::string> node_argv{ "fuzz_env" };

  std::vector<std::string> exec_argv;

  std::vector<std::string> errors;

  node::InitializeNodeWithArgs(&node_argv, &exec_argv, &errors);

  tracing_agent = std::make_unique<node::tracing::Agent>();

  node::tracing::TraceEventHelper::SetAgent(tracing_agent.get());

  node::tracing::TracingController* tracing_controller =

    tracing_agent->GetTracingController();  

  CHECK_EQ(0, uv_loop_init(&current_loop));

  static constexpr int kV8ThreadPoolSize = 4;

  platform.reset(

    new node::NodePlatform(kV8ThreadPoolSize, tracing_controller));

  v8::V8::InitializePlatform(platform.get());

  cppgc::InitializeProcess(platform->GetPageAllocator());

  v8::V8::Initialize();

  return 0;

}

class FuzzerFixtureHelper {

public:

  v8::Isolate* isolate_;

  ArrayBufferUniquePtr allocator;

  FuzzerFixtureHelper()

    : allocator(ArrayBufferUniquePtr(node::CreateArrayBufferAllocator(),

                                     &node::FreeArrayBufferAllocator)) {

    isolate_ = NewIsolate(allocator.get(), &current_loop, platform.get());

    CHECK_NOT_NULL(isolate_);

    isolate_->Enter();

  };

  void Teardown() {

    platform->DrainTasks(isolate_);

    isolate_->Exit();

    platform->UnregisterIsolate(isolate_);

    isolate_->Dispose();

    isolate_ = nullptr;

  }

};

std::string S1 = 

  "const Stream = require('stream');\n"

  "const readableStream = new Stream.Readable();\n"

  "readableStream.push('";

std::string S2 = 

  "');\n"

  "readableStream.push(null);\n"

  "async function getContentReadStream(readable) {\n"

  " for await (const chunk of readable) {\n"

      "   var _ = chunk;\n"

      "   var _ = chunk.toString();\n"

  " }\n"

  "}\n"

  "getContentReadStream(readableStream);\n";

void EnvTest(v8::Isolate* isolate_, char* env_string) {

  const v8::HandleScope handle_scope(isolate_);

  Argv argv;

  node::EnvironmentFlags::Flags flags = node::EnvironmentFlags::kDefaultFlags;

  auto isolate = handle_scope.GetIsolate();

  v8::Local<v8::Context> context_ = node::NewContext(isolate);

  context_->Enter();

  node::IsolateData* isolate_data_ = node::CreateIsolateData(isolate, &current_loop,

                                                             platform.get());

  std::vector<std::string> args(*argv, *argv + 1);

  std::vector<std::string> exec_args(*argv, *argv + 1);

  node::Environment* environment_ = node::CreateEnvironment(isolate_data_,

                                          context_, args, exec_args, flags);

  node::Environment* envi = environment_;

  SetProcessExitHandler(envi, [&](node::Environment* env_, int exit_code) {

    node::Stop(envi);

  });

  node::LoadEnvironment(envi, env_string);

  // Cleanup!

  node::FreeEnvironment(environment_);

  node::FreeIsolateData(isolate_data_);

  context_->Exit();

}

extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data2, size_t size) {

  FuzzedDataProvider prov(data2, size);

  std::string r1 = prov.ConsumeRemainingBytesAsString();

  if (hasUnescapedSingleQuotes(r1)) {

    return 0;

  }

  std::stringstream stream;

  stream << S1 << r1 << S2 << std::endl;

  FuzzerFixtureHelper ffh;

  std::string js_code = stream.str();

  EnvTest(ffh.isolate_, (char*)js_code.c_str());

  ffh.Teardown();

  return 0;

}